I'm following the article by Xamarin that describes how to customize a pin using an image here
protected override MarkerOptions CreateMarker(Pin pin)
{
var marker = new MarkerOptions();
marker.SetPosition(new LatLng(pin.Position.Latitude, pin.Position.Longitude));
marker.SetTitle(pin.Label);
marker.SetSnippet(pin.Address);
marker.SetIcon(BitmapDescriptorFactory.FromResource(Resource.Drawable.pin));
return marker;
}
I have a png image in resources/drawable. However, the map does not show any pins. I put a breakpoint in the custom renderer and it hits so I know its being called. Here is the code for the page that implements the custom map:
Xaml
<controls:CustomMap MapType="Street" x:Name="map" WidthRequest="150" IsVisible="True" HasZoomEnabled="True" HasScrollEnabled="True">
<controls:CustomMap.HeightRequest>
<OnIdiom>
<OnIdiom.Phone>
<OnPlatform
iOS="250"
Android="150" />
</OnIdiom.Phone>
</OnIdiom>
</controls:CustomMap.HeightRequest>
</controls:CustomMap>
and the code behind
var position = new Xamarin.Forms.Maps.Position(item.Latitude.Value, item.Longitude.Value); // Latitude, Longitude
var pin = new CustomPin
{
Type = PinType.Place,
Position = position,
Label = item.Name,
Address = item.AddressString
};
pin.Clicked += async (sender, e) =>
{
await Navigation.PushAsync(new RestaurantDetails(item));
};
Device.BeginInvokeOnMainThread(() =>
{
map.Pins.Add(pin);
map.CustomPins.Add(pin);
// map.MoveToRegion(MapSpan.FromCenterAndRadius(position, Distance.FromMiles(0.3)));
});
This is solved, didn't put the images also in the drawable-xxxx folders. UGH!
For me, the issue was the CustomMap class which I was adding the CustomPins to did not raise the CreateMarker overridden method.
It may help someone else to know that you may see this same issue where the Pins do not appear on your CustomMap if you are adding your CustomPin objects to the CustomPin collection. I was able to fix this by adding each of them to the Pins collection as well.
Related
I've an Editor on a page in my Xamarin Forms Project and I'm looking to amend the placeholder text position by adding a slight margin.
I was able to add a margin to the text the user types (but not the placeholder) using "TextContainerInset" in my iOS Custom renderer.
protected override void OnElementChanged(ElementChangedEventArgs<Editor> e)
{
base.OnElementChanged(e);
this.Control.InputAccessoryView = null;
this.Control.Layer.CornerRadius = 10;
this.Control.Layer.BorderColor = UIColor.LightGray.CGColor;
this.Control.Layer.BorderWidth = (nfloat)0.5;
this.Control.TextContainerInset = new UIEdgeInsets(15,15,15,15);
}
However, this inset doesn't apply to the placeholder position.
Is there a way to move the placeholder position using the custom renderer?
You could set the padding like:
public class MyEntryRenderer : EntryRenderer
{
protected override void OnElementChanged (ElementChangedEventArgs<Entry> e)
{
base.OnElementChanged (e);
if (Control != null) {
Control.LeftView = new UIView(new CGRect(0,0,15,0));
Control.LeftViewMode = UITextFieldViewMode.Always;
Control.RightView = new UIView(new CGRect(0, 0, 15, 0));
Control.RightViewMode = UITextFieldViewMode.Always;
}
}
}
Workaournd for editor:
warp the editor in the frame and set the padding like:
<StackLayout Margin="20">
<Frame CornerRadius="10" BorderColor="Gray" HeightRequest="50" Padding="5,10,5,10" HasShadow="False">
<Editor Placeholder="Enter the editor text" ></Editor>
</Frame>
</StackLayout>
The underlying UITextView does not implement the Placeholder. However if you look at the EditorRenderer code which derives from UITextView, Xamarin has implemented the Placeholder there.
private UILabel _placeholderLabel;
By using reflection, I can get a pointer to the UILabel _placeholderLabel, but I can't for the life of me move it.
If someone can help me move the UILabel, I believe we have the answer!
protected override void OnElementChanged(ElementChangedEventArgs<Editor> e)
{
base.OnElementChanged(e);
if (Control != null)
{
editor = e.NewElement as EditorEx;
//Use reflection to access private placeholder in parent
//https://www.c-sharpcorner.com/UploadFile/6f0898/how-to-access-a-private-member-of-a-class-from-other-class/
System.Reflection.FieldInfo receivedObject = typeof(EditorRenderer).GetFields(System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)[1];
_placeholderLabel = receivedObject.GetValue(this) as UILabel;
_placeholderLabel.Text = "move me!!; //this works
_placeholderLabel.BackgroundColor = UIColor.Green; //this works
//put it on another message to see if that solves it (it doesn't)
Device.BeginInvokeOnMainThread(() =>
{
//HELP NEEDED HERE!!!
//_placeholderLabel.Frame = new CGRect(-15, -10, 500, 30); //doesn't work
//_placeholderLabel.Bounds = new CGRect(-15, -10, 500, 30); //doesn't work
_placeholderLabel.LayoutMargins = new UIEdgeInsets(-15, -10, 5, 5); //doesn't work
});
}
}
I have a grid on my page with a few items.
I want to change the location/span of these items in C#.
On Xaml I can do this:
<Grid>
<Label Grid.Row="1" Grid.RowSpan="2"/>
</Grid>
I could do grd.Children.Remove and then grd.Children.Add in the new position, but is there another way?
public MyPage()
{
var grid = new Grid();
var lbl1 = new Label { Text= "lbl1" };
var lbl2 = new Label { Text = "lbl2" };
grid.Children.Add(lbl1);
grid.Children.Add(lbl2);
Grid.SetRow(lbl1, 1);
Grid.SetRow(lbl2, 0);
this.Content = grid;
}
However I would recommend not to do it dynamically but once in the constructor. More info in the official doc.
Solved: The answer was to update all of the nuget packages and target a newer version of Android. Now images loads as expected. I'm not happy with this as I was using exactly the code that Xamarin provided and targeting newer versions has deprecated some of the items the code relys on. Initial version was Xamarin.Forms v23 and I updated to V25
I have a brand new Xamarin forms project with a simple view in which I'm trying to display an image. I've tried several ways of getting an image to display and I am not having any luck at all.
I'm using <image> and I have also tried FFImageLoader control as well.
<StackLayout Orientation="Vertical">
<ff:CachedImage Source="https://static.pexels.com/photos/104827/cat-pet-animal-domestic-104827.jpeg" WidthRequest="100" HeightRequest="100" />
<Button x:Name="btn" Text="Image" Clicked="Button_Clicked" />
<Frame OutlineColor="Red">
<Image x:Name="StupidImage" Source="{Binding Thumbnail}" Aspect="Fill" HeightRequest="100" WidthRequest="100" />
</Frame>
</StackLayout>
This is the current view. I've also set the Source directly to a value with no result.
I'm able to get a stream for the image. I'm able to read all of the bytes from the stream. I built a debug visualizer to display the bytes as an image. Getting the image from a source is not a problem. Getting the image control(s) to display the image is a problem.
I tried binding with a view model. When that failed, I tried that directly setting the source
StupidImage.Source = ImageSource.FromStream(() => result.Stream);
I also made a copy of the bytes and tried
StupidImage.Source = ImageSource.FromStream(() => new MemoryStream(imageBytes));
I've tried ImageSource.FromFile() and .FromUri. I tried adding an image to the project as a resource. Each try was the same, the resource was read and the bytes were available, but the image control just doesn't display it.
I thought maybe it was a size problem, so I set the size of the control. Nothing. I thought maybe it was a resolution problem, so I used a smaller image. I tried several different images of varying quality.
Then I gave up on the image control and I got the FFImageLoading nuget package and gave it a direct url to an image. Same example that FFImageLoading examples used. Still no image.
I tried the emulator and I tried 2 different physical devices. Same result.
I also tried setting an image on a button using btn.Image = "whatever.jpg" with the same result.
This is the result every time. I'm lost. How do I get images to display?
EDIT:
I did get this to work, but only on the emulator
<Image x:Name="StupidImage" Source="https://static.pexels.com/photos/104827/cat-pet-animal-domestic-104827.jpeg" />
and same for
StupidImage.Source = ImageSource.FromUri(new Uri("https://static.pexels.com/photos/104827/cat-pet-animal-domestic-104827.jpeg"));
EDIT 2 - Clarification
My goal is to allow the user to select a photo from the device and then display a preview of it.
If you want to use images in you app you can load them into your Shared Project, like
Make sure you change the Build Action to Embedded resource
Then in your code
image.Source = ImageSource.FromResource("App5.Images.useravatar.png");
Note the Resource name.
And XAML
<ContentPage.Content>
<StackLayout>
<Image x:Name="image" WidthRequest="50"/>
</StackLayout>
</ContentPage.Content>
Just a few things you can take off the list:
[x] Adding a image from Visual studio :
Right click on the correct folder
select Add >> New File ...
NB: you have to add it with visual studio and not just throw it in the folder. Visual studio needs to know about it
[x] When Adding the image is it in the correct place :
For android: it has to be in
ProjectName.Driod.Resources.drawable folder
For ios: it has to be in
ProjectName.iOS.Resources folder
[x] Naming Convention
Its always best to use .png , all lowercase , no spaces or special char on both android and ios
with ios you normally get 3 images of the same image with the following namting convention
theman.png
theman#2x.png
theman#3x.png
They are all the same image just different sizes
[x] Showing it in xaml :
<StackLayout>
<Image Source="thedog.png" HeightRequest="100" WidthRequest="100" />
</StackLayout>
In your example you used a frame , how about a stacklayout ? a frame has more requirements.
for MVVM you can change Source with the following , dont forget that twoway :)
Source="{Binding Thumbnail, Mode=TwoWay}"
NB This is VERY basic explanations
You can try implementing the CrossMedia Plugin.
Then in your button clicked code section, put the following:
Button_Clicked.Clicked += async (sender, args) =>
{
if ( !CrossMedia.Current.IsPickPhotoSupported )
{
DisplayAlert("Error message here", "More message", "OK");
return;
}
var file = await Plugin.Media.CrossMedia.Current.PickPhotoAsync(new Plugin.Media.Abstractions.PickMediaOptions
{
PhotoSize = Plugin.Media.Abstractions.PhotoSize.Medium
});
if (file == null)
return;
image.Source = ImageSource.FromStream(() =>
{
var stream = file.GetStream();
file.Dispose();
return stream;
});
};
Once the button is clicked, the gallery/directory will be displayed. You can choose the photo you want. Once you hit OK the image will be displayed in the Image control/tag. I'm not sure if this is the solution you are looking for. Hopes it gets you on the right direction.
This may or may not help I'll add some code, one of the surprising things about Xamarin forms and Android and using a memory stream.. is that the device density multiplier is still applied even if you aren't using a resource(If I am remembering correctly) so I would imagine if you are looking at the ADB interface you will see memory issues which is why you cant display an image... I solved this previously via sampling
The way I solved it was creating a new Image subclass -ResourceImage,
public class ResourceImage :Image
{
public enum SourceTypes{
Database,
File,
Function,
}
private bool _LoadAct = false;
public bool LoadAct { get{
return _LoadAct;
}
set{ _LoadAct = value; OnPropertyChanged ("LoadAct");
}
}
public Func<Stream> Func{ get; set; }
public SourceTypes SourceType{ get; set;}
public string ResName{ get; set;}
public ResourceImage ()
{
}
public ResourceImage (string name)
{
ResName = name;
}
public ResourceImage(Func<Stream> func){
SourceType = SourceTypes.Function;
Func = func;
}
}
then in the Android Renderer : I did the following
public class ResourceImageRenderer : ImageRenderer
{
protected override void OnElementChanged (ElementChangedEventArgs<Image> e)
{
base.OnElementChanged (e);
if (e.OldElement == null)
{
var el = (ResourceImage)Element;
if (el.SourceType == ResourceImage.SourceTypes.Database) {
//Ignore for now
} else if (el.SourceType == ResourceImage.SourceTypes.File) {
using (global::Android.Graphics.BitmapFactory.Options options = new global::Android.Graphics.BitmapFactory.Options ()) {
options.InJustDecodeBounds = false;
options.InSampleSize = 1;//calculateInSampleSize (options, outS.X / 4, outS.Y / 4);
var gd = Context.Resources.GetIdentifier (el.ResName.Split (new char[]{ '.' }) [0], "drawable", Context.PackageName);
using (global::Android.Graphics.Rect rt = new global::Android.Graphics.Rect (0, 0, 0, 0)) {
var bitmap = global::Android.Graphics.BitmapFactory.DecodeResource (Context.Resources, gd, options);//DecodeStream (ms, rt, options);
bitmap.Density = global::Android.Graphics.Bitmap.DensityNone;
Control.SetImageDrawable (new global::Android.Graphics.Drawables.BitmapDrawable (bitmap));
}
}
} else if (el.SourceType == ResourceImage.SourceTypes.Function) {
new Task (() => {
var ms = el.Func();
if(ms == null)return;
global::Android.Graphics.BitmapFactory.Options options = new global::Android.Graphics.BitmapFactory.Options ();
options.InJustDecodeBounds = false;
options.InSampleSize = 2;//calculateInSampleSize (options, outS.X / 4, outS.Y / 4);
ms.Position = 0;
Device.BeginInvokeOnMainThread(()=>{
using (global::Android.Graphics.Rect rt = new global::Android.Graphics.Rect (0, 0, 0, 0)) {
try{
var bitmap = global::Android.Graphics.BitmapFactory.DecodeStream (ms, rt, options);
bitmap.Density = global::Android.Graphics.Bitmap.DensityNone;
Control.SetImageDrawable (new global::Android.Graphics.Drawables.BitmapDrawable (bitmap));
}catch(Exception eee){
}
}
});
}).Start();
}
}
}
Looking back at the code(haven't touched it in years.) there are plenty of places for improvement, I had to add the sampling to solve the same issue , users were selecting images to display in a messaging app and it worked perfectly on iOS just never displayed on Android
This is how I allow a user to select an image and then display it on a page.
I call my image service Select Image method passing in a callback method
await _imageService.SelectImage(ImageSelected);
This is my SelectImage method. There is some permission checking at the start. It uses the Media Plugin to display the gallery and allow the user to select an image.
public async Task SelectImage(Action<MediaFile> imageAction)
{
var allowed = await _permissionService.CheckOrRequestStoragePermission();
if (!allowed) return;
if (!_media.IsPickPhotoSupported)
{
throw new GalleryUnavailableException("Gallery unavailable");
}
var file = await _media.PickPhotoAsync(new PickMediaOptions
{
PhotoSize = PhotoSize.Small,
CompressionQuality = 92
});
imageAction(file);
}
It returns a MediaFile
Here is the Image Selected callback method
private void ImageSelected(MediaFile image)
{
if (image == null)
{
return;
}
ChosenImage = new IncidentImage
{
ImageBytes = image.ToByteArray()
};
}
ChosenImage is a Property in my view model
public IncidentImage ChosenImage {get; set;}
I use PropertyChanged.Fody to trigger property changed notifications but you can also use INotifyPropertyChanged.
And IncidentImage is a class I use to both store and display images
public class IncidentImage
{
[PrimaryKey, AutoIncrement]
public int Id { get; set; }
public int IncidentDetailsId { get; set; }
public byte[] ImageBytes { get; set; }
[Ignore]
public ImageSource ImageSource
{
get
{
ImageSource retval = null;
try
{
if (ImageBytes != null)
{
retval = ImageSource.FromStream(() => new MemoryStream(ImageBytes));
}
}
catch (Exception e)
{
Debug.WriteLine(e);
}
return retval;
}
}
}
And here is the XAML
<Image Source="{Binding ChosenImage.ImageSource}"
Aspect="AspectFit"/>
How do I change the height of a Xamarin Forms ProgressBar in code? Am using Xamarin Forms V2.1.
.HeightRequest and .MinimumHeightRequest seem to have no effect. The default progress bar is so thin that it might not even be noticed.
.BackgroundColor does not seem to work either.
What am I missing here?
You need custom renderers for this:
First create a class for your custom progress bar:
public class CustomProgressBar :ProgressBar
{
public CustomProgressBar()
{
}
}
And then also add a new file for your custom progress bar renderer:
For iOS:
public class CustomProgressBarRenderer : ProgressBarRenderer
{
protected override void OnElementChanged(
ElementChangedEventArgs<Xamarin.Forms.ProgressBar> e)
{
base.OnElementChanged(e);
Control.ProgressTintColor = Color.FromRgb(182, 231, 233).ToUIColor();// This changes the color of the progress
}
public override void LayoutSubviews()
{
base.LayoutSubviews();
var X = 1.0f;
var Y = 10.0f; // This changes the height
CGAffineTransform transform = CGAffineTransform.MakeScale(X, Y);
Control.Transform = transform;
}
}
[EDIT: fixed code above as per comment]
For Android:
public class CustomProgressBarRenderer :ProgressBarRenderer
{
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.ProgressBar> e)
{
base.OnElementChanged(e);
Control.ProgressTintList = Android.Content.Res.ColorStateList.ValueOf(Color.FromRgb(182, 231, 233).ToAndroid()); //Change the color
Control.ScaleY = 10; //Changes the height
}
}
I hope this helps you!
To make the progress bar thicker, you just have to change the ScaleY property of the ProgressBar.
For example:
This code
<ProgressBar Progress=".5"/>
<ProgressBar ScaleY="2" Progress=".5"/>
<ProgressBar ScaleY="5" Progress=".5"/>
Produces this
Note that you may need to adjust your margins accordingly.
<ProgressBar
BackgroundColor="White"
ProgressColor="#BCC7EF"
Progress="0.7">
<ProgressBar.ScaleY>
<OnPlatform
x:TypeArguments="x:Double"
iOS="2"
Android="1" />
</ProgressBar.ScaleY>
#BillF is correct basically
In the iOS renderer code try using
this.Control.Transform = transform;
instead of
this.Transform = transform;
I faced the same need and on the latest version of Visual Studio, 16.5.2 I figured out that to get a bigger horizontal bar you just need to set ScaleY within the progressbar declaration inside the xml.
To avoid glitches on Android and be sure that the progress bar is not overwhelming other elements I added a margin as you can see from the declaration here below.
<ProgressBar
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/progressBar1"
android:layout_below="#+id/message"
android:scaleY="8"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"/>
For me, the most simple solution is to use Xamarin.Forms.Visual.Material
Then in your XAML, in progress bar set HeightRequest property to what you want and use Visual property as Material.
i want to create a greeting card maker app for WP7, when a user double taps an image from a listbox, I want that selected image to fill a rectangle on the same page.
Im passing 50 images into the list box like this:
public GCM()
{
InitializeComponent();
var articles = new List<Article>();
for (byte i = 1; i <= 20; i++)
{
Article article = new Article() { Name = "name"+i, ImagePath = "Assets/Images/Backgrounds/"+i+".jpg" };
articles.Add(article);
}
listBox1.DataContext = articles;
}
and its working fine, now heres an xml snippet:
<Rectangle Fill="#FFF4F4F5" Margin="28,24,30,148" Stroke="Black" Name="rect1" />
................(more code here).........................
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Margin="10" >
<Image Name="bgs" Source="{Binding ImagePath}" Height="90" Width="90" DoubleTap="Load_BG" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
how can i fill the rectangle with the tapped image? this code (below) sets the string null everytime, no matter which image i select, although to my knowledge each has a different name and it should give different names for different images. I will use the name of the image to fill the rectangle. What am i doing wrong?
private void Load_BG(object sender, System.Windows.Input.GestureEventArgs e)
{
string abc = sender.GetType().Name;
}
Please excuse me if the solution is obvious..this is my first app ever. Thank you!
sender parameter should contains the control that triggered the event, in this case Image control. Try to cast it to Image type, then you can get the information you needed from Source property :
private void Load_BG(object sender, System.Windows.Input.GestureEventArgs e)
{
Image img = (Image)sender;
//do something with img.Source here
}
so heres the solution, it works now :)
private void listBox1_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
var img = listBox1.SelectedItem as Article;
ImageBrush imgBrush = new ImageBrush();
imgBrush.ImageSource = new BitmapImage(new Uri(img.ImagePath, UriKind.RelativeOrAbsolute));
rect1.Fill = imgBrush;
}