I am implementing code for SwitchRenderer in Android but it appears that there is an issue with the code as I get a warning:
'SwitchRender.SwitchRender()' is obsolete; 'This constuctor is
obsolets as of version 2.5. Please use SwitchRender(Context) instead.'
Does anyone have any ideas how I can resolve this problem:
using Japanese.Android;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;
using Japanese;
[assembly: ExportRenderer(typeof(ExtSwitch), typeof(ExtSwitchRenderer))]
namespace Japanese.Android
{
public class ExtSwitchRenderer : SwitchRenderer
{
private ExtSwitch view;
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Switch> e)
{
base.OnElementChanged(e);
if (e.OldElement != null || e.NewElement == null)
return;
view = (ExtSwitch)Element;
if (Android.OS.Build.VERSION.SdkInt >= Android.OS.BuildVersionCodes.JellyBean)
{
if (this.Control != null)
{
if (this.Control.Checked)
{
this.Control.TrackDrawable.SetColorFilter(view.SwitchOnColor.ToAndroid(), PorterDuff.Mode.SrcAtop);
}
else
{
this.Control.TrackDrawable.SetColorFilter(view.SwitchOffColor.ToAndroid(), PorterDuff.Mode.SrcAtop);
}
this.Control.CheckedChange += this.OnCheckedChange;
UpdateSwitchThumbImage(view);
}
//Control.TrackDrawable.SetColorFilter(view.SwitchBGColor.ToAndroid(), PorterDuff.Mode.Multiply);
}
}
private void UpdateSwitchThumbImage(CustomSwitch view)
{
if (!string.IsNullOrEmpty(view.SwitchThumbImage))
{
view.SwitchThumbImage = view.SwitchThumbImage.Replace(".jpg", "").Replace(".png", "");
int imgid = (int)typeof(Resource.Drawable).GetField(view.SwitchThumbImage).GetValue(null);
Control.SetThumbResource(Resource.Drawable.icon);
}
else
{
Control.ThumbDrawable.SetColorFilter(view.SwitchThumbColor.ToAndroid(), PorterDuff.Mode.Multiply);
// Control.SetTrackResource(Resource.Drawable.track);
}
}
private void OnCheckedChange(object sender, CompoundButton.CheckedChangeEventArgs e)
{
if (this.Control.Checked)
{
this.Control.TrackDrawable.SetColorFilter(view.SwitchOnColor.ToAndroid(), PorterDuff.Mode.SrcAtop);
}
else
{
this.Control.TrackDrawable.SetColorFilter(view.SwitchOffColor.ToAndroid(), PorterDuff.Mode.SrcAtop);
}
}
protected override void Dispose(bool disposing)
{
this.Control.CheckedChange -= this.OnCheckedChange;
base.Dispose(disposing);
}
}
}
Check out the answer here. The new way to do Android custom renderers would be this:
public class ExtSwitchRenderer : SwitchRenderer
{
private ExtSwitch view;
public ExtSwitchRenderer(Context context) : base(context) { }
....
}
Then if you actually need to use the Android context in your custom renderer, you would use the one passed in through the constructor, instead of Forms.Context for example.
Related
I am trying to implement this solution offered as an answer here: Opening target="_blank" links with Xamarin.Forms WebView
In the Android project I have created a custom renderer which has these code excerpts:
[assembly: ExportRenderer(typeof(HybridWebView), typeof(MyApp.controls.HybridWebViewRenderer))]
public class HybridWebViewRenderer : WebViewRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.WebView> e)
{
base.OnElementChanged(e);
Control.Settings.SetSupportMultipleWindows(true);
}
}
In my shared project I have created a HybridWebView which has among others these excerpts of code:
public class HybridWebView : WebView
{
public override bool OnCreateWindow(Android.Webkit.WebView view, bool isDialog, bool isUserGesture, Android.OS.Message resultMsg)
{
Android.Webkit.WebView newWebView = new Android.Webkit.WebView(_context);
view.AddView(newWebView);
Android.Webkit.WebView.WebViewTransport transport = (Android.Webkit.WebView.WebViewTransport)resultMsg.Obj;
transport.WebView = newWebView;
resultMsg.SendToTarget();
return true;
}
}
This gives as a result the following error:
CS0115 'HybridWebViewRenderer.OnCreateWindow(WebView, bool, bool, Message)': no suitable method found to override
Any idea how to overcome this issue?
As far as I'm concerned,we do not need to override the OnCreateWindow in custom renderer in Target project.Also, please take care of the OnElementChanged method in Custom Webview.We need set SetSupportMultipleWindows to true,enabled JS,set SetWebChromeClient, set WebViewClient,set AddJSInterface and last but not least, LoadUrl for the webview.
Below is the code snippet for your reference:
[assembly: ExportRenderer(typeof(HybridWebView),
typeof(HybridWebViewRenderer))]
namespace AppHybridWebView.Droid
{
public class HybridWebViewRenderer : WebViewRenderer
{
public HybridWebViewRenderer(Context context) : base(context)
{
_context = context;
}
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.WebView> e)
{
base.OnElementChanged(e);
if (Control != null)
{
Control.Settings.SetSupportMultipleWindows(false);
Control.Settings.JavaScriptEnabled = true;
Control.SetWebChromeClient(new MyWebChromeClient());
Control.SetWebViewClient(new JavascriptWebViewClient(this, $"javascript: {JavascriptFunction}"));
Control.AddJavascriptInterface(new JSBridge(this), "jsBridge");
Control.LoadUrl($"file:///android_asset/Content/{((HybridWebView)Element).Uri}");//LoadUrl
}
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
((HybridWebView)Element).Cleanup();
}
base.Dispose(disposing);
}
}
public class MyWebChromeClient : WebChromeClient
{
public override bool OnCreateWindow(Android.Webkit.WebView view, bool isDialog, bool isUserGesture, Message resultMsg)
{
if (!isDialog)
{
return true;
}
return base.OnCreateWindow(view, isDialog, isUserGesture, resultMsg);
}
}
}
Code in xaml:
<local:HybridWebView x:Name="hybridWebView" Uri="index.html" />
I have an application that responds to a short tap on the screen. I do this by adding a gesture recognizer.
Is there a way that I can make it respond to either a short or a long press and have these call different methods?
You will have implement renderers for that. In case of iOS you can use UILongPressGestureRecognizer to detect a long-press action, while in case of Android, you can use GestureDetector to do the same.
Forms control
public class CustomView : ContentView
{
public event EventHandler<EventArgs> LongPressEvent;
public void RaiseLongPressEvent()
{
if (IsEnabled)
LongPressEvent?.Invoke(this, EventArgs.Empty);
}
}
iOS renderer
[assembly: ExportRenderer(typeof(CustomView), typeof(CustomViewRenderer))]
namespace AppNamespace.iOS
{
public class CustomViewRenderer : ViewRenderer<CustomView, UIView>
{
UILongPressGestureRecognizer longPressGestureRecognizer;
protected override void OnElementChanged(ElementChangedEventArgs<CustomView> e)
{
longPressGestureRecognizer = longPressGestureRecognizer ??
new UILongPressGestureRecognizer(() =>
{
Element.RaiseLongPressEvent();
});
if (longPressGestureRecognizer != null)
{
if (e.NewElement == null)
{
this.RemoveGestureRecognizer(longPressGestureRecognizer);
}
else if (e.OldElement == null)
{
this.AddGestureRecognizer(longPressGestureRecognizer);
}
}
}
}
}
Android renderer
[assembly: ExportRenderer(typeof(CustomView), typeof(CustomViewRenderer))]
namespace AppNamespace.Droid
{
public class CustomViewRenderer : ViewRenderer<CustomView, Android.Views.View>
{
private CustomViewListener _listener;
private GestureDetector _detector;
public CustomViewListener Listener
{
get
{
return _listener;
}
}
public GestureDetector Detector
{
get
{
return _detector;
}
}
protected override void OnElementChanged(ElementChangedEventArgs<CustomView> e)
{
base.OnElementChanged(e);
if (e.OldElement == null)
{
GenericMotion += HandleGenericMotion;
Touch += HandleTouch;
_listener = new CustomViewListener(Element);
_detector = new GestureDetector(_listener);
}
}
protected override void Dispose(bool disposing)
{
GenericMotion -= HandleGenericMotion;
Touch -= HandleTouch;
_listener = null;
_detector?.Dispose();
_detector = null;
base.Dispose(disposing);
}
void HandleTouch(object sender, TouchEventArgs e)
{
_detector.OnTouchEvent(e.Event);
}
void HandleGenericMotion(object sender, GenericMotionEventArgs e)
{
_detector.OnTouchEvent(e.Event);
}
}
public class CustomViewListener : GestureDetector.SimpleOnGestureListener
{
readonly CustomView _target;
public CustomViewListener(CustomView s)
{
_target = s;
}
public override void OnLongPress(MotionEvent e)
{
_target.RaiseLongPressEvent();
base.OnLongPress(e);
}
}
}
Sample Usage
<local:CustomView LongPressEvent="Handle_LongPress" />
Code-behind
void Handle_LongPressEvent(object sender, System.EventArgs e)
{
//handle long press event here
}
You can also customize above to add a command to make it more MVVM friendly.
You can refer this link for more details regarding gesture recognizers.
http://arteksoftware.com/gesture-recognizers-with-xamarin-forms/
You will have implement renderers for that. In case ios and android
best way for do that!
Is there a way to detect a long tap on an image control in Xamarin Forms?
I'm using the carousel view to display images and would like to give the option to delete them by selecting with a long tap.
Based on your suggestions in the comments this is what I did:
(The purpose of the control is to be able to select an Image with a LongTap)
I defined my own Image control in the PCL:
IsSelected BindableProperty.
LongTap event.
public class MyImage:Image
{
private BindableProperty IsSelectedProperty = BindableProperty.Create("IsSelected", typeof(bool), typeof(MyImage), false);
public bool IsSelected {
get {
return (bool)GetValue(IsSelectedProperty);
}
set {
SetValue(IsSelectedProperty, value);
}
}
public event EventHandler LongClick;
public void OnLongClick()
{
IsSelected = !IsSelected;
if(IsSelected)
{
Opacity = 0.5;
}
else
{
Opacity = 1;
}
if (LongClick != null)
{
LongClick(this, EventArgs.Empty);
}
}
}
And this is my custom renderer: (Defined in the Android project)
[assembly: ExportRenderer(typeof(MyImage), typeof(MyImageRenderer))]
namespace PRISMCarouselView.Droid.Renderes
{
public class MyImageRenderer : ImageRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<Image> e)
{
base.OnElementChanged(e);
if (Control != null)
{
ImageView androidSource = Control as ImageView;
MyImage myImage = e.NewElement as MyImage;
androidSource.LongClick += (object sender, LongClickEventArgs ee) =>
{
myImage.OnLongClick();
};
}
}
}
}
Edit 1:
Here's a slightly updated version, I use the BindingPropertyChangedDelegate to change the opacity of the image:
public class SelectableImage : Image
{
public SelectableImage()
{
}
private static BindableProperty IsSelectedProperty = BindableProperty.Create("IsSelected",
typeof(bool),
typeof(SelectableImage),
false, BindingMode.Default, null, (sender, o1, o2) => {
SelectableImage imageControl = sender as SelectableImage;
if(imageControl != null)
{
if(imageControl.IsSelected)
{
imageControl.Opacity = 0.5;
}else
{
imageControl.Opacity = 1;
}
}
});
public bool IsSelected {
get {
return (bool)GetValue(IsSelectedProperty);
}
set {
SetValue(IsSelectedProperty, value);
}
}
}
And the renderer:
[assembly: ExportRenderer(typeof(SelectableImage), typeof(SelectableImageRenderer))]
namespace Muserma.Apps.Droid.Renderer
{
public class SelectableImageRenderer : ImageRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<Image> e)
{
base.OnElementChanged(e);
if (Control != null)
{
ImageView androidSource = Control as ImageView;
SelectableImage selectableImage = e.NewElement as SelectableImage;
androidSource.LongClick += (object sender, LongClickEventArgs ee) =>
{
selectableImage.IsSelected = !selectableImage.IsSelected;
};
}
}
}
}
I'm trying to implement the functionality of the android button through a ButtonRender. The problem occurs when I try to join ".LongClick" and ".touch", since it does not launch the long click event.
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Button> e)
{
this.SetBackgroundResource(Resource.Drawable.button);
base.OnElementChanged(e);
Android.Widget.Button thisButton = Control as Android.Widget.Button;
thisButton.LongClickable = true;
thisButton.LongClick += delegate
{
string s = "";
};
thisButton.Touch += (object sender, Android.Views.View.TouchEventArgs e2) =>
{
if (e2.Event.Action == MotionEventActions.Down)
{
.
.
.
}
else if (e2.Event.Action == MotionEventActions.Up)
{
.
.
.
}
else if (e2.Event.Action == MotionEventActions.HoverExit || e2.Event.Action == MotionEventActions.Cancel)
{
.
.
.
}
else if (e2.Event.Action == MotionEventActions.Move)
{
.
.
.
}
};
}
To invoke the event of native control, we need to create event handlers in our custom control, and together an interface which inherits from IViewController in order to set values from renderers.
Here is my demo, first of all, create a custom button:
public class MyButton : Xamarin.Forms.Button, IMyButtonController
{
public event EventHandler Touched;
void IMyButtonController.SendTouched()
{
Touched?.Invoke(this, EventArgs.Empty);
}
public event EventHandler LongClicked;
void IMyButtonController.SendLongClicked()
{
LongClicked?.Invoke(this, EventArgs.Empty);
}
public event EventHandler Released;
void IMyButtonController.SendReleased()
{
Released?.Invoke(this, EventArgs.Empty);
}
}
The IMyButtonController inherits from IViewController like this:
public interface IMyButtonController : IViewController
{
void SendTouched();
void SendLongClicked();
void SendReleased();
}
Then in android project, implement the ButtonRenderer and IMyButtonController like this:
[assembly: ExportRenderer(typeof(MyButton), typeof(MyButtonRenderer))]
namespace ProjectNameSpace.Droid
{
public class MyButtonRenderer : Xamarin.Forms.Platform.Android.ButtonRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Button> e)
{
base.OnElementChanged(e);
if (e.NewElement != null)
{
if (Control != null)
{
Control.SetOnTouchListener(ButtonTouchListener.Instance.Value);
Control.LongClickable = true;
Control.SetOnLongClickListener(ButtonLongClickListener.Instance.Value);
}
}
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
if (Control != null)
{
Control.SetOnTouchListener(null);
Control.SetOnLongClickListener(null);
}
}
base.Dispose(disposing);
}
private class ButtonTouchListener : Java.Lang.Object, Android.Views.View.IOnTouchListener
{
public static readonly Lazy<ButtonTouchListener> Instance = new Lazy<ButtonTouchListener>(() => new ButtonTouchListener());
public bool OnTouch(Android.Views.View v, Android.Views.MotionEvent e)
{
var renderer = v.Tag as ButtonRenderer;
if (renderer != null)
{
var buttonController = renderer.Element as IMyButtonController;
if (e.Action == Android.Views.MotionEventActions.Down)
{
buttonController?.SendTouched();
}
else if (e.Action == Android.Views.MotionEventActions.Up)
{
buttonController?.SendReleased();
}
}
return false;
}
}
private class ButtonLongClickListener : Java.Lang.Object, Android.Views.View.IOnLongClickListener
{
public static readonly Lazy<ButtonLongClickListener> Instance = new Lazy<ButtonLongClickListener>(() => new ButtonLongClickListener());
public bool OnLongClick(Android.Views.View v)
{
var renderer = v.Tag as ButtonRenderer;
((IMyButtonController)renderer?.Element)?.SendLongClicked();
return true;
}
}
}
}
I want to create a renderer for an entry field using Xamarin. What is the best way to get it? I have no idea how to get it, any help will be appreciate.
This is my entry field and I want to create font size renderer for that
<Entry x:Name="txtTest"/>
This is sample of Entry that set padding to 0 and can set TextSize property.
namespace projectname
{
public class BareEntry : Entry
{
public BareEntry ()
{
}
public static readonly BindableProperty TextSizeProperty =
BindableProperty.Create<BareEntry,int> (X => X.TextSize, 10);
public int TextSize
{
get {return (int)base.GetValue (TextSizeProperty);}
set {base.SetValue (TextSizeProperty, value);}
}
}
}
This part is on android platform
using Xamarin.Forms;
using projectname;
using projectname.Droid;
using Xamarin.Forms.Platform.Android;
using MocMSearch.Droid;
using Android.Support.V4.Content;
[assembly: ExportRenderer (typeof (BareEntry), typeof (BareEntryRenderer))]
namespace MocMSearch.Droid
{
public class BareEntryRenderer : EntryRenderer
{
public BareEntryRenderer ()
{
}
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Entry> e)
{
base.OnElementChanged(e);
Recreate ();
}
void Recreate()
{
if (this.Control == null) return;
Control.SetPadding (0,0,0,0);
Control.SetTextSize (Android.Util.ComplexUnitType.Mm,(Element as BareEntry).TextSize);
}
protected override void OnElementPropertyChanged (object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged (sender, e);
if (e.PropertyName == "TextSize")
{
Recreate ();
this.Invalidate ();
}
}
}
}