I'm trying to implement Darkmode for Android by using the new AppThemeBinding. It works fine for Android and iOS but i do not have a clue on how to implement it for custom renderers or custom styles.
For example i got a custom Stepper renderer which looks something like this:
protected override void OnElementChanged(ElementChangedEventArgs<Stepper> e)
{
base.OnElementChanged(e);
if (Control != null)
{
Android.Widget.Button buttonDown = (Android.Widget.Button)Control.GetChildAt(0);
Android.Widget.Button buttonUp = (Android.Widget.Button)Control.GetChildAt(1);
if(e.NewElement != null)
{
//Button Down
buttonDown.SetBackgroundResource(Resource.Drawable.button_bg_left);
buttonDown.LayoutParameters = new LinearLayout.LayoutParams(DpToPixel(50), DpToPixel(33));
buttonDown.SetPadding(0,0,0,0);
buttonDown.SetTextColor(Android.Graphics.Color.ParseColor("#007bff"));
//Button Up
buttonUp.SetBackgroundResource(Resource.Drawable.button_bg_right);
buttonUp.LayoutParameters = new LinearLayout.LayoutParams(DpToPixel(50), DpToPixel(33));
buttonUp.SetPadding(0, 0, 0, 0);
buttonUp.SetTextColor(Android.Graphics.Color.ParseColor("#007bff"));
}
}
}
I'm setting a background resource which is a .xml file and looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="#FFFFFF"/>
<stroke android:width="1dp" android:color="#007bff" />
<corners
android:topLeftRadius="5dp"
android:bottomLeftRadius="5dp"/>
</shape>
Since the AppThemeBinding is a Markup Extension and works inside .xaml files, i have no clue how i could implement color changes for my android specific renderers?
How could i go about changing the color of my custom shape for Light/Darkmode?
You can Detect the current system theme in the renderer and then set the corresponding color:
class MyStepperRenderer : StepperRenderer
{
public MyStepperRenderer(Context context) : base(context)
{
}
protected override void OnElementChanged(ElementChangedEventArgs<Stepper> e)
{
base.OnElementChanged(e);
OSAppTheme currentTheme = Xamarin.Forms.Application.Current.RequestedTheme;
if (currentTheme == OSAppTheme.Light)
{
//
}
else
{
//
}
}
}
Related
in my application i am using PushModalAsync and PopModalAsync for page navigation but page animation is displaying from bottom top and top to bottom respectively. Is there any other option to animate page from right to left or left to right?
Welcome to SO!
If using PushModelAsync , there is a workaround to achieve that effect .
Create a CustomPageRenderer for PageTwo in iOS solution :
[assembly: ExportRenderer(typeof(PageTwo), typeof(CustomPageRenderer))]
namespace XamarinMoelNavigationStyle.iOS
{
public class CustomPageRenderer :PageRenderer
{
public override void ViewWillAppear(bool animated)
{
var transition = CATransition.CreateAnimation();
transition.Duration = 0.5f;
transition.Type = CAAnimation.TransitionPush;
transition.Subtype = CAAnimation.TransitionFromRight;
View.Layer.AddAnimation(transition, null);
base.ViewWillAppear(animated);
}
}
}
We will add animation inside ViewWillAppear method .
When poping to previous MainPage , we can deal with that in ContentPage as follow :
private void Button_Clicked(object sender, EventArgs e)
{
PageTwoView.TranslateTo(300, 0, 500);
Device.StartTimer(TimeSpan.FromSeconds(0.5), () =>
{
// Do something
Navigation.PopModalAsync(false);
return false; // True = Repeat again, False = Stop the timer
});
}
Here PageTwoView is defined from Xaml :
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
x:Name="PageTwoView"
x:Class="XamarinMoelNavigationStyle.PageTwo">
...
</ContentPage>
Note : When MainPage navigate to PageTwo , need to disable the animation .
Such as :
private void Button_Clicked(object sender, EventArgs e)
{
Navigation.PushModalAsync(new PageTwo(), false);
}
The effect :
===============================Update #1==============================
Also create a CustomPageRenderer for PageTwo in Android solution :
public class CustomPageRenderer : PageRenderer
{
public CustomPageRenderer(Context context) : base(context)
{
}
protected override void OnAttachedToWindow()
{
var metrics = Resources.DisplayMetrics;
Android.Views.Animations.Animation translateAnimation = new TranslateAnimation(metrics.WidthPixels, 0, 0, 0);
translateAnimation.Duration = 500;
Animation = translateAnimation;
translateAnimation.Start();
base.OnAttachedToWindow();
}
}
The effect:
===============================Update #2=================================
If there are much ContentPages need to navigate, you can modify the CustomPageRenderer to be used for all ContentPage. As follow:
[assembly: ExportRenderer(typeof(ContentPage), typeof(CustomPageRenderer))]
...
Then using Preferences to set flag in Forms and get flag to know whether need the animation.
private void Button_Clicked(object sender, EventArgs e)
{
PageTwo pageTwo = new PageTwo();
// set a flag here
Preferences.Set("ModelAnimation", true);
Navigation.PushModalAsync(pageTwo, false);
}
Now the renderer will know whehter need the animatin:
//Android
protected override void OnAttachedToWindow()
{
var myValue = Preferences.Get("ModelAnimation", false);
if (myValue)
{
var metrics = Resources.DisplayMetrics;
Android.Views.Animations.Animation translateAnimation = new TranslateAnimation(metrics.WidthPixels, 0, 0, 0);
translateAnimation.Duration = 500;
Animation = translateAnimation;
translateAnimation.Start();
}
base.OnAttachedToWindow();
}
//iOS
public override void ViewWillAppear(bool animated)
{
var myValue = Preferences.Get("ModelAnimation", false);
if (myValue)
{
var transition = CATransition.CreateAnimation();
transition.Duration = 0.5f;
transition.Type = CAAnimation.TransitionPush;
transition.Subtype = CAAnimation.TransitionFromRight;
View.Layer.AddAnimation(transition, null);
}
base.ViewWillAppear(animated);
}
after sliding complete 1st page is open as popup and not looking like first page to second page animation..
About this issue, you can share some code and .gif to explain that.
I have some pages in Xamarin.Forms,since I need to build a custom camera,so I used Xamarin.Android.
now I need to go to Xamarin.Android/iOS from page of Xamarin.Forms and and back to Xamarin.Forms again. how can I do it?
pls help
You don't necessarily need to jump between Xamarin.Forms Views/Pages and Project Specific (iOS/Android) Views manually you can do it by using CustomRenderes which are part of Xamarin.Forms.
Basically you would create a Custom Page on Xamarin.Forms then specifying in each platform project how you want that page to look. You would attach this CustomRender to your Custom Page (the one you made in Xamarin.Forms) and the Framework would do the rest for you.
You can read about Custom Renderers here. And you can see a very similar example of what you are looking right in the Xamarin documentation here.
Hope this helps.-
Welcome to SO !
Baesd on a Xamarin Forms project , you can use Custom Renderer to achieve that .
Such as Creating the Custom Control :
public class CameraPreview : View
{
public static readonly BindableProperty CameraProperty = BindableProperty.Create (
propertyName: "Camera",
returnType: typeof(CameraOptions),
declaringType: typeof(CameraPreview),
defaultValue: CameraOptions.Rear);
public CameraOptions Camera {
get { return (CameraOptions)GetValue (CameraProperty); }
set { SetValue (CameraProperty, value); }
}
}
In Xaml :
<ContentPage ...
xmlns:local="clr-namespace:CustomRenderer;assembly=CustomRenderer"
...>
<ContentPage.Content>
<StackLayout>
<Label Text="Camera Preview:" />
<local:CameraPreview Camera="Rear"
HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" />
</StackLayout>
</ContentPage.Content>
</ContentPage>
Now you can create the Custom Renderer on each Platform.
Android :
[assembly: ExportRenderer(typeof(CustomRenderer.CameraPreview), typeof(CameraPreviewRenderer))]
namespace CustomRenderer.Droid
{
public class CameraPreviewRenderer : ViewRenderer<CustomRenderer.CameraPreview, CustomRenderer.Droid.CameraPreview>
{
CameraPreview cameraPreview;
public CameraPreviewRenderer(Context context) : base(context)
{
}
protected override void OnElementChanged(ElementChangedEventArgs<CustomRenderer.CameraPreview> e)
{
base.OnElementChanged(e);
if (e.OldElement != null)
{
// Unsubscribe
cameraPreview.Click -= OnCameraPreviewClicked;
}
if (e.NewElement != null)
{
if (Control == null)
{
cameraPreview = new CameraPreview(Context);
SetNativeControl(cameraPreview);
}
Control.Preview = Camera.Open((int)e.NewElement.Camera);
// Subscribe
cameraPreview.Click += OnCameraPreviewClicked;
}
}
void OnCameraPreviewClicked(object sender, EventArgs e)
{
if (cameraPreview.IsPreviewing)
{
cameraPreview.Preview.StopPreview();
cameraPreview.IsPreviewing = false;
}
else
{
cameraPreview.Preview.StartPreview();
cameraPreview.IsPreviewing = true;
}
}
...
}
}
iOS :
[assembly: ExportRenderer (typeof(CameraPreview), typeof(CameraPreviewRenderer))]
namespace CustomRenderer.iOS
{
public class CameraPreviewRenderer : ViewRenderer<CameraPreview, UICameraPreview>
{
UICameraPreview uiCameraPreview;
protected override void OnElementChanged (ElementChangedEventArgs<CameraPreview> e)
{
base.OnElementChanged (e);
if (e.OldElement != null) {
// Unsubscribe
uiCameraPreview.Tapped -= OnCameraPreviewTapped;
}
if (e.NewElement != null) {
if (Control == null) {
uiCameraPreview = new UICameraPreview (e.NewElement.Camera);
SetNativeControl (uiCameraPreview);
}
// Subscribe
uiCameraPreview.Tapped += OnCameraPreviewTapped;
}
}
void OnCameraPreviewTapped (object sender, EventArgs e)
{
if (uiCameraPreview.IsPreviewing) {
uiCameraPreview.CaptureSession.StopRunning ();
uiCameraPreview.IsPreviewing = false;
} else {
uiCameraPreview.CaptureSession.StartRunning ();
uiCameraPreview.IsPreviewing = true;
}
}
...
}
}
More info can refer to this official sample .
I have this custompicker class in android project:
public class CustomPickerRenderer : PickerRenderer
{
private Context context;
private IElementController ElementController => Element as IElementController;
private AlertDialog _dialog;
public CustomPickerRenderer(Context context) : base(context)
{
this.context = context;
}
protected override void OnElementChanged(ElementChangedEventArgs<Picker> e)
{
base.OnElementChanged(e);
if (Control == null || e.NewElement == null) return;
Control.Click += Control_Click1;
}
protected override void Dispose(bool disposing)
{
Control.Click -= Control_Click1;
base.Dispose(disposing);
}
private void Control_Click1(object sender, EventArgs e)
{
Picker model = Element;
var picker = new NumberPicker(Context);
if (model.Items != null && model.Items.Any())
{
picker.MaxValue = model.Items.Count - 1;
picker.MinValue = 0;
picker.SetDisplayedValues(model.Items.ToArray());
picker.WrapSelectorWheel = false;
picker.DescendantFocusability = DescendantFocusability.BlockDescendants;
picker.Value = model.SelectedIndex;
}
var layout = new LinearLayout(Context) { Orientation = Orientation.Vertical };
layout.AddView(picker);
ElementController.SetValueFromRenderer(VisualElement.IsFocusedProperty, true);
var builder = new AlertDialog.Builder(Context);
builder.SetView(layout);
builder.SetTitle(model.Title ?? "");
//change the text or color here
builder.SetNegativeButton(Html.FromHtml("<font color='#039BE5'>Cancel</font>"), (s, a) =>
{
ElementController.SetValueFromRenderer(VisualElement.IsFocusedProperty, false);
// It is possible for the Content of the Page to be changed when Focus is changed.
// In this case, we'll lose our Control.
Control?.ClearFocus();
_dialog = null;
});
//change the text or color here
builder.SetPositiveButton(Html.FromHtml("<font color='#039BE5'>OK</font>"), (s, a) =>
{
ElementController.SetValueFromRenderer(Picker.SelectedIndexProperty, picker.Value);
// It is possible for the Content of the Page to be changed on SelectedIndexChanged.
// In this case, the Element & Control will no longer exist.
if (Element != null)
{
if (model.Items.Count > 0 && Element.SelectedIndex >= 0)
Control.Text = model.Items[Element.SelectedIndex];
ElementController.SetValueFromRenderer(VisualElement.IsFocusedProperty, false);
// It is also possible for the Content of the Page to be changed when Focus is changed.
// In this case, we'll lose our Control.
Control?.ClearFocus();
}
_dialog = null;
});
_dialog = builder.Create();
_dialog.DismissEvent += (ssender, args) =>
{
ElementController?.SetValueFromRenderer(VisualElement.IsFocusedProperty, false);
};
_dialog.Show();
}
}
I tried running my project on my phone Xiaomi POCOPHONE F1 (Android 9) and 2 emulators (Android 8.1) and the colors of cancel and ok buttons are designed Perfectly. But when I tried running the project on Huawei PLE-701L and SAMSUNG SM-T365 (Android 5.1) the color of the buttons didn't changed.
Any suggestions?
Get the button object through the API of dialog and set the text color of the button. This method can be personalized. One point needs to be noted: it must be called after show
in your custom renderer,below _dialog.Show();
....
_dialog.Show();
Button btnOk = _dialog.GetButton((int)DialogInterface.ButtonPositive);
btnOk .SetTextColor(Color.Red);
Button btnCancel= _dialog.GetButton((int)DialogInterface.ButtonNegative);
btnCancel.SetTextColor(Color.Red);
add this style in style.xml
<style name="SpinnerDialog" parent="Theme.AppCompat.Light.Dialog">
<item name="android:popupBackground">#ff00ff</item>
<item name="colorPrimary">#ff00ff</item>
<item name="colorPrimaryDark">#ffff00</item>
<item name="colorAccent">#ff0000</item>
</style>
you can change allthe color including buttons.
and you can also use
<style name="AlertDialogCustom" parent="android:Theme.Material.Light.Dialog.Alert">
<item name="android:colorPrimary">#1e87f0</item>
<item name="android:colorAccent">#1e87f0</item>
</style>
<style name="AppCompatDialogStyle" parent="Theme.AppCompat.Light.Dialog">
<item name="colorAccent">#1e87f0</item>
</style>
The Question is answered here: Picker button's color not changing on android 5.1
I added the styles code in the correct answer in the link, and it worked!
I would like to extend all the contentpages in my xamarin.forms app with a native view in UWP. I can basically go to each and every page and embed a native view but i dont want this. I want to know if there is a way to do it using a pagerenderer. I tried doing like below.
my idea was to get current page rendering and extend the content with native view and stacklayout and define app.content again with this change. It works in general. If you run the small test project below, you can see that native UWP FontIcons are displayed for each page but there is a problem, if i navigate same page 2 times in MasterDetail in the attached project, page becomes blank. Why is this happening?
and is the approach below best for my case? I am open for alternative solutions.
[assembly: ExportRenderer(typeof(ContentPage), typeof(App3.UWP.ContentPageRenderer))]
namespace App3.UWP
{
public class ContentPageRenderer : PageRenderer
{
bool isDisposing = false;
protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Page> e)
{
base.OnElementChanged(e);
if (isDisposing)
return;
if (e.OldElement != null || Element == null)
{
return;
}
ContentPage page = ((ContentPage)Element);
if (page.Content == null)
return;
var XboxControls = new MyUserControl1();
StackLayout stackLayout = new StackLayout() { Orientation = StackOrientation.Vertical };
stackLayout.Children.Add(page.Content);
stackLayout.Children.Add(XboxControls.ToView());
page.Content = stackLayout;
}
protected override Windows.Foundation.Size ArrangeOverride(Windows.Foundation.Size finalSize)
{
return base.ArrangeOverride(finalSize);
}
protected override void Dispose(bool disposing)
{
isDisposing = disposing;
base.Dispose(disposing);
}
}
Test Project
I want to add a button which should be above the listView as same as how the whatsapp people have done and i want the same thing by using Xamarin Forms, i have tried doing with the xlab PopupLayout but i was unable to fix the position of the button as shown in the image the problem is with the different screen sizes and orientations..
So can any1 help me how to fix the location of the popup by using xlab popuplayout in xamarin forms and it should handle all the screen sizes and orientations.
Have a look at this great post by Alex Dunn. He implements a Floating Action Button (as it is called) on Android and iOS through Xamarin.Forms. It is basic, but you can extend on it yourself.
The gist is you create a control in your shared code, like this:
public partial class FloatingActionButton : Button
{
public static BindableProperty ButtonColorProperty = BindableProperty.Create(nameof(ButtonColor), typeof(Color), typeof(FloatingActionButton), Color.Accent);
public Color ButtonColor
{
get
{
return (Color)GetValue(ButtonColorProperty);
}
set
{
SetValue(ButtonColorProperty, value);
}
}
public FloatingActionButton()
{
InitializeComponent();
}
}
Now on Android implement a custom renderer, like this:
using FAB = Android.Support.Design.Widget.FloatingActionButton;
[assembly: ExportRenderer(typeof(SuaveControls.Views.FloatingActionButton), typeof(FloatingActionButtonRenderer))]
namespace SuaveControls.FloatingActionButton.Droid.Renderers
{
public class FloatingActionButtonRenderer : Xamarin.Forms.Platform.Android.AppCompat.ViewRenderer<SuaveControls.Views.FloatingActionButton, FAB>
{
protected override void OnElementChanged(ElementChangedEventArgs<SuaveControls.Views.FloatingActionButton> e)
{
base.OnElementChanged(e);
if (e.NewElement == null)
return;
var fab = new FAB(Context);
// set the bg
fab.BackgroundTintList = ColorStateList.ValueOf(Element.ButtonColor.ToAndroid());
// set the icon
var elementImage = Element.Image;
var imageFile = elementImage?.File;
if (imageFile != null)
{
fab.SetImageDrawable(Context.Resources.GetDrawable(imageFile));
}
fab.Click += Fab_Click;
SetNativeControl(fab);
}
protected override void OnLayout(bool changed, int l, int t, int r, int b)
{
base.OnLayout(changed, l, t, r, b);
Control.BringToFront();
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
var fab = (FAB)Control;
if (e.PropertyName == nameof(Element.ButtonColor))
{
fab.BackgroundTintList = ColorStateList.ValueOf(Element.ButtonColor.ToAndroid());
}
if (e.PropertyName == nameof(Element.Image))
{
var elementImage = Element.Image;
var imageFile = elementImage?.File;
if (imageFile != null)
{
fab.SetImageDrawable(Context.Resources.GetDrawable(imageFile));
}
}
base.OnElementPropertyChanged(sender, e);
}
private void Fab_Click(object sender, EventArgs e)
{
// proxy the click to the element
((IButtonController)Element).SendClicked();
}
}
}
And on iOS, like this:
[assembly: ExportRenderer(typeof(SuaveControls.Views.FloatingActionButton), typeof(FloatingActionButtonRenderer))]
namespace SuaveControls.FloatingActionButton.iOS.Renderers
{
[Preserve]
public class FloatingActionButtonRenderer : ButtonRenderer
{
public static void InitRenderer()
{
}
public FloatingActionButtonRenderer()
{
}
protected override void OnElementChanged(ElementChangedEventArgs<Button> e)
{
base.OnElementChanged(e);
if (e.NewElement == null)
return;
// remove text from button and set the width/height/radius
Element.WidthRequest = 50;
Element.HeightRequest = 50;
Element.BorderRadius = 25;
Element.BorderWidth = 0;
Element.Text = null;
// set background
Control.BackgroundColor = ((SuaveControls.Views.FloatingActionButton)Element).ButtonColor.ToUIColor();
}
public override void Draw(CGRect rect)
{
base.Draw(rect);
// add shadow
Layer.ShadowRadius = 2.0f;
Layer.ShadowColor = UIColor.Black.CGColor;
Layer.ShadowOffset = new CGSize(1, 1);
Layer.ShadowOpacity = 0.80f;
Layer.ShadowPath = UIBezierPath.FromOval(Layer.Bounds).CGPath;
Layer.MasksToBounds = false;
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == "ButtonColor")
{
Control.BackgroundColor = ((SuaveControls.Views.FloatingActionButton)Element).ButtonColor.ToUIColor();
}
}
}
}
You should now be able to use your button from XAML and code as you like.
Here is the XAML sample:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:local="clr-namespace:SuaveControls.FabExample" xmlns:controls="clr-namespace:SuaveControls.Views;assembly=SuaveControls.FloatingActionButton" x:Class="SuaveControls.FabExample.MainPage">
<StackLayout Margin="32">
<Label Text="This is a Floating Action Button!" VerticalOptions="Center" HorizontalOptions="Center"/>
<controls:FloatingActionButton x:Name="FAB" HorizontalOptions="CenterAndExpand" WidthRequest="50" HeightRequest="50" VerticalOptions="CenterAndExpand" Image="ic_add_white.png" ButtonColor="#03A9F4" Clicked="Button_Clicked"/>
</StackLayout>
</ContentPage>
Please note that all credits for this go out to Alex. All his code for this is up here. In the past I have also used the NControls code code to create something like this. And I'm sure there are more awesome libraries out there. However, have a good look at the support for libraries. If I'm not mistake the XLabs packages aren't supported anymore.