I am getting following exception when implementing the code below the exception.
Java.lang.IllegalStateException: The specific child already has a parent. you must call the removeView() on the child's parent first.
using System;
using Android.Support.V7.Widget;
using Android.Views;
using Android.Widget;
using Android.App;
namespace Recycle.Droid
{
internal class albumadapter1 : RecyclerView.Adapter
{
// private int[] imageid;
// private Photo_album palbum;
// private _Recycler _Recycler;
private int[] imageid;
private Activity mainActivity;
public albumadapter1(Activity context, int[] imageid)
{
this.mainActivity = context;
this.imageid = imageid;
}
public override int ItemCount
{
get
{
return imageid.Length;
}
}
public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
PhotoViewHolder vh1 = holder as PhotoViewHolder;
vh1.img.SetImageResource(imageid[position]);
//vh.Caption.Text = palbum[position].Caption;
}
public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
{
var itemview = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.view_holder, parent);
PhotoViewHolder vh = new PhotoViewHolder(itemview);
return vh;
}
}
public class PhotoViewHolder : RecyclerView.ViewHolder
{
public TextView tv { get; private set; }
public ImageView img { get; private set; }
public PhotoViewHolder(View itemView) : base(itemView)
{
img = itemView.FindViewById<ImageView>(Resource.Id.imageView1);
// var Caption = itemView.FindViewById<TextView>(Resource.Id.textView);
// public PhotoViewHolder(IntPtr javaReference, JniHandleOwnership transfer) : base(javaReference, transfer)
}
}
}
please help me with problem.
Add False to the code below your issue will be solved
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public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
{
var itemview = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.view_holder, parent, false);
PhotoViewHolder vh = new PhotoViewHolder(itemview);
return vh;
}
.....
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.
Related
I am working to achieve a recycler view interface that looks like this:
Presently, am only using a recyclerview with LinearLayoutManager using an adapter with two viewholders, i tried gridLayout manager too but i did not achieve the target interface: I need help achieving this, Do i have to create a custom Layout Manager? or What exactly do i have to do? Please, I am really stuck on this.
This is my adapter code
public class SimpleStringRecyclerViewAdapter : RecyclerView.Adapter
{
private List<Data> mValues;
private Context context;
private const int TYPE_FULL = 0;
private const int TYPE_HALF = 1;
private const int TYPE_QUARTER = 2;
public SimpleStringRecyclerViewAdapter(Context context, List<Data> items)
{
this.context = context;
mValues = items;
}
public override int ItemCount
{
get
{
return mValues.Count();
}
}
public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
if (holder is SimpleViewHolder)
try
{
Data item = mValues.ElementAt(position);
var simpleHolder = holder as SimpleViewHolder;
simpleHolder.mTxtView.Text = Android.Text.Html.FromHtml(item.article.Title).ToString();
simpleHolder.mTxtView2.Text = item.article.Description;
using (var imageView = simpleHolder.mImageView)
{
string url = Android.Text.Html.FromHtml(item.article.UrlToImage).ToString();
//Download and display image
UrlImageViewHelper.SetUrlDrawable(imageView,
url, Resource.Drawable.cheese_1
);
}
// simpleHolder.mprogressbar.Visibility = ViewStates.Gone;
}
catch (Exception e)
{
//Toast.MakeText(this.context, e.ToString(), ToastLength.Long).Show();
}
else
{
try
{
Data item = mValues.ElementAt(position);
var simpleHolder = holder as SimpleViewHolder2;
simpleHolder.mTxtView.Text = Android.Text.Html.FromHtml(item.youTubeItem.Title).ToString();
// simpleHolder.mTxtView2.Text = item.DescriptionShort;
using (var imageView = simpleHolder.mImageView)
{
string url = Android.Text.Html.FromHtml(item.youTubeItem.MaxResThumbnailUrl).ToString();
//Download and display image
UrlImageViewHelper.SetUrlDrawable(imageView,
url, Resource.Drawable.cheese_1
);
}
}
catch (Exception e)
{
//Toast.MakeText(this.context, e.ToString(), ToastLength.Long).Show();
}
}
}
public override int GetItemViewType(int position)
{
if (mValues.ElementAt(position).type == 1)
{
return Resource.Layout.ItemsList;
}
else
{
return Resource.Layout.VideoList;
}
}
public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
{
if (viewType == Resource.Layout.ItemsList)
{
View view = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.ItemsList, parent, false);
view.SetBackgroundColor(Color.White);
SimpleViewHolder holder = new SimpleViewHolder(view);
// holder.mprogressbar = view.FindViewById<ProgressBar>(Resource.Id.progressBar);
// holder.mprogressbar.Visibility = ViewStates.Visible;
//Showing loading progressbar
return holder;
}
else
{
View view = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.VideoList, parent, false);
view.SetBackgroundColor(Color.White);
SimpleViewHolder2 holder = new SimpleViewHolder2(view);
return holder;
}
}
}
public class SimpleViewHolder : RecyclerView.ViewHolder
{
public string mBoundString;
public readonly View mView;
public readonly ImageView mImageView;
public readonly TextView mTxtView;
public readonly TextView mTxtView2;
// public ProgressBar mprogressbar;
public SimpleViewHolder(View view) : base(view)
{
mView = view;
mImageView = view.FindViewById<ImageView>(Resource.Id.avatar2);
mTxtView = view.FindViewById<TextView>(Resource.Id.Text11);
mTxtView2 = view.FindViewById<TextView>(Resource.Id.Text12);
// mprogressbar = view.FindViewById<ProgressBar>(Resource.Id.progressBar);
}
public override string ToString()
{
return base.ToString() + " '" + mTxtView.Text;
}
}
public class SimpleViewHolder2 : RecyclerView.ViewHolder
{
public string mBoundString;
public readonly View mView;
public readonly ImageView mImageView;
public readonly TextView mTxtView;
public readonly TextView mTxtView2;
public SimpleViewHolder2(View view) : base(view)
{
mView = view;
mImageView = view.FindViewById<ImageView>(Resource.Id.videoavatar);
mTxtView = view.FindViewById<TextView>(Resource.Id.videoText1);
// mprogressbar = view.FindViewById<ProgressBar>(Resource.Id.progressBar);
}
}
SetUpRecyclerView Method:
dataUse = OfflineDeserializer.OfflineData(content, json2);
recyclerView.SetLayoutManager(new LinearLayoutManager(recyclerView.Context));
recyclerView.SetAdapter(new SimpleStringRecyclerViewAdapter(recyclerView.Context, dataUse));
if (vp.IsShown)
{
vp.Visibility = ViewStates.Invisible;
}
This is what I have presently:
you can use recycler view with multiple view type
here is the link you can refer
Recyclerview with multiple view types
Here is a sample code you can modify it according to your need
public class MyFeedsAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
final int
VIDEO = 1,
IMAGE = 2,
AUDIO = 3;
public MyFeedsAdapter(HomeActivity homeActivity, ArrayList<MyFeedsModel> list, MyFeedsFragment myFeedsFragment) {
this.activity = homeActivity;
this.list = list;
this.myFeedsFragment = myFeedsFragment;
metrics = new DisplayMetrics();
activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view;
switch (viewType) {
case VIDEO:
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_myfeeds, parent, false);
return new ViewForVideo(view);
case IMAGE:
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_myfeeds, parent, false);
return new ViewForImage(view);
case AUDIO:
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_myfeeds, parent, false);
return new ViewForAudio(view);
default:
return null;
}
}
#Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) {
if (list.get(position).getFile_type().equals(IntentString.VIDEO)) {
setViewForVideo((ViewForVideo) holder, position);
} else if (list.get(position).getFile_type().equals(IntentString.IMAGE)) {
setViewForImage((ViewForImage) holder, position);
} else if (list.get(position).getFile_type().equals(IntentString.AUDIO)) {
setViewForAudio((ViewForAudio) holder, position);
}
}
#Override
public int getItemCount() {
return list.size();
}
#Override
public int getItemViewType(int position) {
if (list.get(position).getFile_type().equals(IntentString.VIDEO)) {
return VIDEO;
} else if (list.get(position).getFile_type().equals(IntentString.IMAGE)) {
return IMAGE;
} else if (list.get(position).getFile_type().equals(IntentString.AUDIO)) {
return AUDIO;
} else {
return 0;
}
}
public void setViewForVideo(final ViewForVideo holder, final int position) {
}
public void setViewForImage(final ViewForImage holder, final int position) {
}
public void setViewForAudio(final ViewForAudio holder, int position) {
}
public class ViewForVideo extends RecyclerView.ViewHolder {
public ViewForVideo(View itemView) {
super(itemView);
}
}
public class ViewForImage extends RecyclerView.ViewHolder {
public ViewForImage(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
public class ViewForAudio extends RecyclerView.ViewHolder {
public ViewForAudio(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
}
I have noticed the RecyclerView.Adapter type is not generic in Xamarin.Android. Why is it so? It seems to be defined as generic in native Android according to the documentation. Is there an underlying reason for this? Or is it some kind of backward compatiblity scenario?
You can create generic RecycleView in C# but not in java. In java you need to write code multiple times. That's why java android is worse even just simple event handler, Android Team Engineers are lazy to implements all data event handling because of the nature of java.
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Support.V7.Widget;
using Android.Util;
using Android.Views;
using Android.Widget;
namespace XamarinAndroid.Basic.Core
{
public class GenericRecyclerViewAdapter<T> : RecyclerView.Adapter
{
/// <summary>
/// You can set this for different custom cardview
/// </summary>
public int CardViewResourceLayout { get; set; }
public ObservableCollection<T> Items { get; private set; }
public event EventHandler<RecyclerViewViewHolder> ItemViewTemplated;
public GenericRecyclerViewAdapter(IEnumerable<T> items, int cardViewResourceLayout) : base()
{
this.Items = new ObservableCollection<T>(items);
this.CardViewResourceLayout = cardViewResourceLayout;
this.Items.CollectionChanged += (sender, e) =>
{
try
{
this.NotifyDataSetChanged();
}
catch { }
};
}
public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
{
var itemView = LayoutInflater.From(parent.Context).Inflate(CardViewResourceLayout, parent, false);
#if DEBUG
Log.Info("GenericRecyclerViewAdapter - ", CardViewResourceLayout.ToString());
#endif
RecyclerViewViewHolder vh = new RecyclerViewViewHolder(itemView);
return vh;
}
public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
RecyclerViewViewHolder vh = holder as RecyclerViewViewHolder;
vh.ItemPosition = position;
vh.TemplateView.Tag = position;
vh.TemplateView.Click -= TemplateView_Click;
vh.TemplateView.Click += TemplateView_Click;
this.ItemViewTemplated?.Invoke(this, vh);
}
public event EventHandler<T> ItemClicked;
private void TemplateView_Click(object sender, EventArgs e)
{
var position = (int)((View)sender).Tag;
this.ItemClicked?.Invoke(this, this.Items[position]);
}
public override int ItemCount
{
get { return this.Items.Count; }
}
public override long GetItemId(int position)
{
return base.GetItemId(position);
}
}
public class RecyclerViewViewHolder : RecyclerView.ViewHolder
{
public View TemplateView { get; private set; }
public int ItemPosition { get; set; }
public RecyclerViewViewHolder(View itemView) : base(itemView)
{
// Locate and cache view references:
this.TemplateView = itemView;
}
}
}
Assigning data to each view
var recyclerViewToday = this.FindViewById<Android.Support.V7.Widget.RecyclerView>(Resource.Id.recyclerViewToday);
var layoutManager = new LinearLayoutManager(this);
recyclerViewToday.SetLayoutManager(layoutManager);
var adapter = new GenericRecyclerViewAdapter<FavoriteModel>(previousList, Resource.Layout.recent_list_item);
adapter.ItemViewTemplated += (d, holder) =>
{
var indicate = holder.ItemView.FindViewById<View>(Resource.Id.indicatorItemmRec);
indicate.SetBackgroundColor(ColorHelper.GetRandomLightColor());
(holder.ItemView.FindViewById<TextView>(Resource.Id.wordTxtRec)).Text = adapter.Items[holder.ItemPosition].Word;
var textView = (holder.ItemView.FindViewById<TextView>(Resource.Id.definitionTxtRec));
if (!string.IsNullOrEmpty(previousList[holder.ItemPosition].Definition))
textView.Text = previousList[holder.ItemPosition].Definition;
else
textView.Visibility = Android.Views.ViewStates.Gone;
};
recyclerViewToday.SetAdapter(adapter);
Result
Clean, Generic and Reusable
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.Graphics;
using Android.OS;
using Android.Runtime;
using Android.Support.V7.App;
using Android.Support.V7.Widget;
using Android.Text;
using Android.Text.Style;
using Android.Util;
using Android.Views;
using Android.Widget;
using Java.Util.Zip;
using ActionMenuView = Android.Support.V7.Widget.ActionMenuView;
namespace Android.Basic.Core
{
public class GenericRecyclerViewAdapter<T> : RecyclerView.Adapter
{
/// <summary>
/// You can set this for different custom cardview
/// </summary>
private int CardViewResourceLayout { get; set; }
public ObservableCollection<T> Items { get; private set; }
public event EventHandler<RecyclerViewViewHolder> ItemViewTemplated;
public RecyclerView.LayoutManager layoutManager;
public GenericRecyclerViewAdapter(RecyclerView recyclerView, IEnumerable<T> items, int cardViewResourceLayout, bool isList = true, bool isVertical = true) : base()
{
if(isList)
{
var vertical = isVertical ? LinearLayoutManager.Vertical : LinearLayoutManager.Horizontal;
layoutManager = new LinearLayoutManager(recyclerView.Context, vertical, false);
}
else
{
var vertical = isVertical ? GridLayoutManager.Vertical : GridLayoutManager.Horizontal;
layoutManager = new GridLayoutManager(recyclerView.Context, 3, vertical, false);
}
recyclerView.SetLayoutManager(layoutManager);
this.Items = new ObservableCollection<T>(items);
this.CardViewResourceLayout = cardViewResourceLayout;
this.Items.CollectionChanged += delegate
{
this.NotifyDataSetChanged();
};
}
public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
{
var itemView = LayoutInflater.From(parent.Context).Inflate(CardViewResourceLayout, parent, false);
#if DEBUG
Log.Info("GenericRecyclerViewAdapter - ", CardViewResourceLayout.ToString());
#endif
RecyclerViewViewHolder vh = new RecyclerViewViewHolder(itemView);
return vh;
}
public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
RecyclerViewViewHolder vh = holder as RecyclerViewViewHolder;
vh.ItemPosition = position;
vh.TemplateView.Tag = position;
vh.TemplateView.Click -= TemplateView_Click;
vh.TemplateView.Click += TemplateView_Click;
ItemViewTemplated?.Invoke(this, vh);
}
public event EventHandler<T> ItemClicked;
private void TemplateView_Click(object sender, EventArgs e)
{
var position = (int)((View)sender).Tag;
this.ItemClicked?.Invoke(sender, this.Items[position]);
}
public override int ItemCount
{
get { return this.Items.Count; }
}
public override long GetItemId(int position)
{
return base.GetItemId(position);
}
}
public class RecyclerViewViewHolder : RecyclerView.ViewHolder, View.IOnCreateContextMenuListener,
IMenuItemOnMenuItemClickListener
{
public View TemplateView { get; private set; }
public int ItemPosition { get; set; }
public event EventHandler<MenuInfo> ContextMenuCreated;
public event EventHandler<object> MenuItemClicked;
public MenuInfo MenuInfo { get; private set; }
public object Data { get; set; }
public RecyclerViewViewHolder(View itemView) : base(itemView)
{
// Locate and cache view references:
this.TemplateView = itemView;
this.TemplateView.SetOnCreateContextMenuListener(this);
}
public void OnCreateContextMenu(IContextMenu menu, View v, IContextMenuContextMenuInfo menuInfo)
{
MenuInfo = new MenuInfo(menu, v, menuInfo);
ContextMenuCreated?.Invoke(this, MenuInfo);
}
private Android.Views.MenuInflater menuInflater = null;
/// <summary>
/// After ContextMenuCreated
/// </summary>
/// <param name="resourcemenu"></param>
public void InflateMenu(int resourcemenu, SpannableString titleColor = null, object dta = null)
{
if (dta != null)
this.Data = dta;
if (this.TemplateView.Context is AppCompatActivity activity)
{
menuInflater = activity.MenuInflater;
}
else if (this.TemplateView.Context is Activity activity2)
{
menuInflater = activity2.MenuInflater;
}
var contextMenu = this.MenuInfo.ContextMenu;
contextMenu.Clear();
menuInflater.Inflate(resourcemenu, contextMenu);
var num = contextMenu.Size() - 1;
for (int i = 0; i <= num; i++)
{
var men = contextMenu.GetItem(i);
if(titleColor != null)
{
if (i == 0)
{
men.SetTitle(titleColor);
men.SetChecked(true);
}
}
if (i != 0)
{
men.SetOnMenuItemClickListener(this);
}
}
}
public bool OnMenuItemClick(IMenuItem item)
{
this.MenuItemClicked?.Invoke(item, this.Data);
return true;
}
public float PosX;
public float PosY;
}
public class MenuInfo
{
public IContextMenu ContextMenu { get; }
public View View { get; }
public IContextMenuContextMenuInfo ContextMenuInfo { get; }
public MenuInfo(IContextMenu contextMenu, View view, IContextMenuContextMenuInfo menuInfo)
{
this.ContextMenu = contextMenu;
this.View = view;
this.ContextMenuInfo = menuInfo;
}
}
}
Usage
RecyclerView recyclerView = context.FindViewById<RecyclerView>(Resource.Id.recycler);
var viewAdapter = new Android.Basic.Core.GenericRecyclerViewAdapter<StorageFile>(recyclerView, files, Resource.Layout.main_item);
viewAdapter.ItemViewTemplated += (dd, holder) =>
{
//CardView
CardView cardView = holder.ItemView.FindViewById<CardView>(Resource.Id.CategorycardView);
cardView.SetCardBackgroundColor(ThemeHelper.IsDark ? Color.ParseColor("#303030") : Color.White);
var indicator = holder.ItemView.FindViewById<LinearLayout>(Resource.Id.indicator);
indicator.SetBackgroundColor(ThemeHelper.IsDark ? ColorHelper.GetRandomLightColor() : ColorHelper.GetRandomDarkColor());
var file = files[holder.ItemPosition];
var itemIcon = holder.ItemView.FindViewById<ImageView>(Resource.Id.itemIcon);
var icon = file.GetFileThumbnail();
if (icon != null)
{
itemIcon.SetImageBitmap(icon);
}
TextView itemName = holder.ItemView.FindViewById<TextView>(Resource.Id.itemName);
itemName.Text = file.DisplayName;
itemName.SetTextColor(textColor);
};
viewAdapter.ItemClicked += (dd, ff) =>
{
var checkBttn = (dd as View).FindViewById<ImageButton>(Resource.Id.check_boxBttn);
};
recyclerView.SetAdapter(viewAdapter);
I'm having a trouble with both ListView and RecyclerView
Initially, I created a ListView, everything is fine. Then I set onClick event for it so that every time I click an item, it changes its color to yellow. The OnClick function I wrote in the MainActivity. Problem is that when I test, not only that item changes its color but 2 items change. I read that it's because I reuse the view.
So I switch my tactics, using RecyclerView instead but same problem occurs. When I click one item to change its color, another below also changes. I guess it's because both ListView and RecyclerView reuse those Item so they confuse when I click one.
I don't know how to solve this problem, I found a solution is to add an array of boolean which marks which item is clicked but it doesn't work. Any idea guys?
So here is the code
MainActivity
class MainActivity : Activity
{
public RecyclerView recyclerView;
public RecyclerView.LayoutManager manager;
public RecyclerView.Adapter adapter;
List<Row> lst;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.Main);
init();
recyclerView = (RecyclerView)FindViewById(Resource.Id.recyclerView);
manager = new LinearLayoutManager(this);
recyclerView.SetLayoutManager(manager);
CustomAdapter adapter = new CustomAdapter(lst, this);
adapter.ItemClick += onItemClick;
recyclerView.SetAdapter(adapter);
}
public void init()
{
lst = new List<Row>();
for (int i = 0; i < 15; i++)
{
Row row = new Row() { field1="1:43:00", field2="09-Apr-16", field3="KPI/Overflow", field4="Kevin Bacon", field5="Unowned", field6= "People Counting # IPCAM-ID-C-1-1" };
lst.Add(row);
}
}
public void onItemClick(object sender, int position)
{
int itemPos = position + 1;
//Toast.MakeText(this, "this is " + itemPos, ToastLength.Short).Show();
recyclerView.GetChildAt(position).SetBackgroundColor(Android.Graphics.Color.Green);
}
}
Custom adapter
public class CustomAdapter : RecyclerView.Adapter
{
public Activity _activity;
public List<Row> lst;
public event EventHandler<int> ItemClick;
public CustomAdapter(List<Row> lst, Activity activity)
{
this.lst = lst;
this._activity = activity;
}
public override int ItemCount
{
get
{
return lst.Count;
}
}
public void OnClick(int position)
{
if (ItemClick!=null)
{
ItemClick(this, position);
}
}
public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
MyViewHolder myholder = holder as MyViewHolder;
myholder.textView1.Text = lst[position].field1;
myholder.textView2.Text = lst[position].field2;
myholder.textView3.Text = lst[position].field3;
myholder.textView4.Text = lst[position].field4;
myholder.textView5.Text = lst[position].field5;
myholder.textView6.Text = lst[position].field6;
}
public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
{
View v = this._activity.LayoutInflater.Inflate(Resource.Layout.item, parent, false);
TextView tv1 = (TextView)v.FindViewById(Resource.Id.textView1);
TextView tv2 = (TextView)v.FindViewById(Resource.Id.textView2);
TextView tv3 = (TextView)v.FindViewById(Resource.Id.textView3);
TextView tv4 = (TextView)v.FindViewById(Resource.Id.textView4);
TextView tv5 = (TextView)v.FindViewById(Resource.Id.textView5);
TextView tv6 = (TextView)v.FindViewById(Resource.Id.textView6);
MyViewHolder holder = new MyViewHolder(v, OnClick) { textView1 = tv1, textView2 = tv2, textView3 = tv3, textView4 = tv4, textView5 = tv5, textView6 = tv6 };
return holder;
}
}
class MyViewHolder : RecyclerView.ViewHolder
{
public TextView textView1, textView2, textView3, textView4, textView5, textView6;
public View mainView;
public MyViewHolder(View view, Action<int> listener) : base(view)
{
mainView = view;
mainView.Click += (sender, e) => listener(base.Position);
}
}
I followed the example for the OnClick handler on Xamarin site
https://developer.xamarin.com/guides/android/user_interface/recyclerview/
Your issue is with your code. You send the correct position to your event handler, but then you increment it by one in the Activity. Both ends should be using the 0-based index of the item position. There is no need to increment by one.
For changing the background color of the selected item, you can use a selector in XML so you wouldn't even need to do this in code.
Here is an example.
row_selector.xml
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_selected="true" android:color="#android:color/green" />
<item android:state_selected="false" android:color="#android:color/transparent"/>
</selector>
row_content.axml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/row_layout_parent"
android:background="#drawable/row_selector">
<!-- your row content -->
</LinearLayout>
Then your view holder would be updated to this...
class MyViewHolder : RecyclerView.ViewHolder
{
public TextView textView1, textView2, textView3, textView4, textView5, textView6;
public View mainView;
private LinearLayout _layoutParent;
public MyViewHolder(View view, Action<int> listener) : base(view)
{
mainView = view;
_layoutParent = mainView.FindViewById<LinearLayout>(Resource.Id.row_layout_parent);
_layoutParent.Click += (sender, e) => _layoutParent.Selected = true;
}
}
I removed the other click event. If you still need it for other reasons, then you can add it back, but it's not necessary for just setting the item background color when selected.
For Listview you should set choiceMode as below.
listView.ChoiceMode = ChoiceMode.Single;
Hope it help you :)-
Create a reusable recycleview adapter GENERIC
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.Graphics;
using Android.OS;
using Android.Runtime;
using Android.Support.V7.App;
using Android.Support.V7.Widget;
using Android.Text;
using Android.Text.Style;
using Android.Util;
using Android.Views;
using Android.Widget;
using Java.Util.Zip;
using ActionMenuView = Android.Support.V7.Widget.ActionMenuView;
namespace Android.Basic.Core
{
public class GenericRecyclerViewAdapter<T> : RecyclerView.Adapter
{
/// <summary>
/// You can set this for different custom cardview
/// </summary>
private int CardViewResourceLayout { get; set; }
public ObservableCollection<T> Items { get; private set; }
public event EventHandler<RecyclerViewViewHolder> ItemViewTemplated;
public RecyclerView.LayoutManager layoutManager;
public GenericRecyclerViewAdapter(RecyclerView recyclerView, IEnumerable<T> items, int cardViewResourceLayout, bool isList = true, bool isVertical = true) : base()
{
if(isList)
{
var vertical = isVertical ? LinearLayoutManager.Vertical : LinearLayoutManager.Horizontal;
layoutManager = new LinearLayoutManager(recyclerView.Context, vertical, false);
}
else
{
var vertical = isVertical ? GridLayoutManager.Vertical : GridLayoutManager.Horizontal;
layoutManager = new GridLayoutManager(recyclerView.Context, 3, vertical, false);
}
recyclerView.SetLayoutManager(layoutManager);
this.Items = new ObservableCollection<T>(items);
this.CardViewResourceLayout = cardViewResourceLayout;
this.Items.CollectionChanged += delegate
{
this.NotifyDataSetChanged();
};
}
public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
{
var itemView = LayoutInflater.From(parent.Context).Inflate(CardViewResourceLayout, parent, false);
#if DEBUG
Log.Info("GenericRecyclerViewAdapter - ", CardViewResourceLayout.ToString());
#endif
RecyclerViewViewHolder vh = new RecyclerViewViewHolder(itemView);
return vh;
}
public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
RecyclerViewViewHolder vh = holder as RecyclerViewViewHolder;
vh.ItemPosition = position;
vh.TemplateView.Tag = position;
vh.TemplateView.Click -= TemplateView_Click;
vh.TemplateView.Click += TemplateView_Click;
ItemViewTemplated?.Invoke(this, vh);
}
public event EventHandler<T> ItemClicked;
private void TemplateView_Click(object sender, EventArgs e)
{
var position = (int)((View)sender).Tag;
this.ItemClicked?.Invoke(sender, this.Items[position]);
}
public override int ItemCount
{
get { return this.Items.Count; }
}
public override long GetItemId(int position)
{
return base.GetItemId(position);
}
}
public class RecyclerViewViewHolder : RecyclerView.ViewHolder, View.IOnCreateContextMenuListener,
IMenuItemOnMenuItemClickListener
{
public View TemplateView { get; private set; }
public int ItemPosition { get; set; }
public event EventHandler<MenuInfo> ContextMenuCreated;
public event EventHandler<object> MenuItemClicked;
public MenuInfo MenuInfo { get; private set; }
public object Data { get; set; }
public RecyclerViewViewHolder(View itemView) : base(itemView)
{
// Locate and cache view references:
this.TemplateView = itemView;
this.TemplateView.SetOnCreateContextMenuListener(this);
}
public void OnCreateContextMenu(IContextMenu menu, View v, IContextMenuContextMenuInfo menuInfo)
{
MenuInfo = new MenuInfo(menu, v, menuInfo);
ContextMenuCreated?.Invoke(this, MenuInfo);
}
private Android.Views.MenuInflater menuInflater = null;
/// <summary>
/// After ContextMenuCreated
/// </summary>
/// <param name="resourcemenu"></param>
public void InflateMenu(int resourcemenu, SpannableString titleColor = null, object dta = null)
{
if (dta != null)
this.Data = dta;
if (this.TemplateView.Context is AppCompatActivity activity)
{
menuInflater = activity.MenuInflater;
}
else if (this.TemplateView.Context is Activity activity2)
{
menuInflater = activity2.MenuInflater;
}
var contextMenu = this.MenuInfo.ContextMenu;
contextMenu.Clear();
menuInflater.Inflate(resourcemenu, contextMenu);
var num = contextMenu.Size() - 1;
for (int i = 0; i <= num; i++)
{
var men = contextMenu.GetItem(i);
if(titleColor != null)
{
if (i == 0)
{
men.SetTitle(titleColor);
men.SetChecked(true);
}
}
if (i != 0)
{
men.SetOnMenuItemClickListener(this);
}
}
}
public bool OnMenuItemClick(IMenuItem item)
{
this.MenuItemClicked?.Invoke(item, this.Data);
return true;
}
public float PosX;
public float PosY;
}
public class MenuInfo
{
public IContextMenu ContextMenu { get; }
public View View { get; }
public IContextMenuContextMenuInfo ContextMenuInfo { get; }
public MenuInfo(IContextMenu contextMenu, View view, IContextMenuContextMenuInfo menuInfo)
{
this.ContextMenu = contextMenu;
this.View = view;
this.ContextMenuInfo = menuInfo;
}
}
}
Usage
RecyclerView recyclerView = new RecyclerView(this);
var viewAdapter = new Android.Basic.Core.GenericRecyclerViewAdapter<Java.IO.File>(recyclerView, files, Resource.Layout.directory_item);
var indiColor = ThemeHelper.IsDark ? ColorHelper.GetRandomLightColor() : ColorHelper.GetRandomDarkColor();
viewAdapter.ItemViewTemplated += (dd, holder) =>
{
var file = files[holder.ItemPosition];
var view = holder.ItemView;
var expanded = view.FindViewById<ExpandedView>(Resource.Id.expandedView);
expanded.SetToggleColor(indiColor);
expanded.SetTitle(file.Name);
GenerateRecycler(expanded, file);
};
recyclerView.SetAdapter(viewAdapter);
expandedView.AddExpandedView(recyclerView);
i have used fresco library to load images in the adapter. but the images are not set correctly as i expected. Here is my code. please help me. thanks in advance.
public class HomeListingAdapter_recyler1 extends RecyclerView.Adapter {
private Context context;
private ArrayList propertyItemList;
private ImageLoader mImageLoader;
public HomeListingAdapter_recyler1(HomeListingActivity_recycler propertyViews, ArrayList propertyItemList) {
Fresco.initialize(propertyViews);
this.propertyItemList = propertyItemList;
this.context = propertyViews;
}
#Override
public CustomViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemLayoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.property_item_layout,parent,false);
CustomViewHolder viewHolder = new CustomViewHolder(itemLayoutView);
return viewHolder;
}
#Override
public void onBindViewHolder(final CustomViewHolder holder, final int position) {
mImageLoader = VolleySingletonPattern.getInstance(context).getImageLoader();
holder.txtPropertyName.setText(propertyItemList.get(position).ville);
holder.txtPropertyType.setText(propertyItemList.get(position).bienName);
if(propertyItemList.get(position).pieces.equalsIgnoreCase("0")){
holder.txtPropertySurfaceArea.setText(propertyItemList.get(position).surface+" "+context.getString(R.string.meter_square));
}else{ holder.txtPropertySurfaceArea.setText(propertyItemList.get(position).surface+" "+context.getString(R.string.meter_square)+" - "+ propertyItemList.get(position).pieces+" "+context.getResources().getString(R.string.pieces));
}
holder.txtPropertyPrice.setText(propertyItemList.get(position).montantLoyer);
Uri imageUri;
try {
if(!TextUtils.isNullOrEmpty(propertyItemList.get(position).photo)) {
imageUri = Uri.parse(propertyItemList.get(position).photo);
holder.imgPropertyImage.setVisibility(View.VISIBLE);
holder.imgPropertyImage.setImageURI(imageUri);
}
} catch (Exception e) {
}
}
#Override
public int getItemCount() {
return propertyItemList.size();
}
public class CustomViewHolder extends RecyclerView.ViewHolder {
SimpleDraweeView imgPropertyImage;
public TextView txtPropertyName , txtPropertyType , txtPropertySurfaceArea ,txtPropertyPrice;
public CustomViewHolder(View itemView) {
super(itemView);
imgPropertyImage = (SimpleDraweeView) itemView.findViewById(R.id.image_property);
txtPropertyName = (TextView) itemView.findViewById(R.id.txt_property_name);
txtPropertyType = (TextView) itemView.findViewById(R.id.txt_property_type);
txtPropertySurfaceArea = (TextView) itemView.findViewById(R.id.txt_property_surface_piece);
txtPropertyPrice = (TextView) itemView.findViewById(R.id.txt_property_price);
}
}
}
Your imgPropertyImage should be a SimpleDraweeView, not an ImageView.
I am getting wrong position in custom ListView while scrolling.
I have tried the ViewHolder pattern and an ArrayAdapter but both giving the same problem.
If I reproduce the code using Java then I am getting the proper position while scrolling.
So is it Xamarin architecture bug ?
Below is my sample code:
Activity Class
namespace ArrayAdapterDemoApp
{
[Activity(Label = "ArrayAdapterDemoApp", MainLauncher = true,
Icon ="#drawable/icon")]
public class MainActivity : Activity
{
private static List<DataBean> _ItemsList = new List<DataBean>();
private static CustomAdapter _adapter;
private ListView _listview;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.Main);
// Get our button from the layout resource,
// and attach an event to it
_listview = FindViewById<ListView>(Resource.Id.mylist);
DataBean obj1 = new DataBean();
obj1.Name = "AA";
obj1.City = "11";
_ItemsList.Add(obj1);
DataBean obj2 = new DataBean();
obj2.Name = "BB";
obj2.City = "22";
_ItemsList.Add(obj2);
DataBean obj3 = new DataBean();
obj3.Name = "CC";
obj3.City = "33";
_ItemsList.Add(obj3);
...
DataBean obj15 = new DataBean();
obj15.Name = "OO";
obj15.City = "1010";
_ItemsList.Add(obj15);
_adapter = new CustomAdapter(this, _ItemsList);
_listview.Adapter = _adapter;
}
}
}
Custom Adapter
namespace ArrayAdapterDemoApp
{
public class CustomAdapter : ArrayAdapter<DataBean>
{
private class TaskViewHolder : Java.Lang.Object
{
public TextView tvName;
public TextView tvCity;
}
List<DataBean> listData;
Activity _context;
int _position;
public CustomAdapter(Activity context, List<DataBean> dataList)
: base(context, Resource.Layout.adapter_row, dataList)
{
this._context = context;
this.listData = dataList;
}
public override long GetItemId(int position)
{
return position;
}
public override int Count
{
get { return listData.Count; }
}
//With View Holder
public override View GetView(int position, View convertView, ViewGroup parent)
{
DataBean data = listData[position];
TaskViewHolder viewHolder= null; // view lookup cache stored in tag
if (convertView == null)
{
viewHolder = new TaskViewHolder();
LayoutInflater inflater = LayoutInflater.From(_context);
convertView = inflater.Inflate(Resource.Layout.adapter_row, parent, false);
viewHolder.tvName = convertView.FindViewById<TextView>(Resource.Id.text1);
viewHolder.tvCity = convertView.FindViewById<TextView>(Resource.Id.text2);
convertView.Tag = viewHolder;
}
if(viewHolder==null)
{
viewHolder = (TaskViewHolder)convertView.Tag;
}
viewHolder.tvName.Text = data.Name;
viewHolder.tvCity.Text = data.City;
return convertView;
}
}
}
DataBean Class
namespace ArrayAdapterDemoApp
{
public class DataBean
{
public string Name { get; set; }
public string City { get; set; }
}
}
I had also same issue so I resolved it by just Tag the position to the view.for example.
//iv_delete is a imageview
holder.iv_delete.Tag = position;
and get the position from the Tag
For me it was like that
int finalPosition = (Integer)holder.iv_delete.Tag.IntValue();
Enjoy!!!!!
Add in your adapter class this method:
public DataBean GetItemAtPosition(int position)
{
return this.listData[position];
}
You can tag the position of each row to the control to get the correct position or
Another method is by using action event binding to each view row. This also solves duplicate method call issue.
this might be helpful: http://appliedcodelog.blogspot.in/2015/07/working-on-issues-with-listview-in.html#WrongPosition