3 回答

• 1

  我在我的应用程序上使用这些属性，对我来说工作正常 . 我将这些属性与“样式”一起使用 .

  例：

  <Style x:Key="buttonStyle" TargetType="Button">
      <Setter Property="BackgroundColor" Value="{DynamicResource Snow}"/>
      <Setter Property="TextColor" Value="{DynamicResource LightBlue}" />
      <Setter Property="BorderColor" Value="{DynamicResource LightBlue}"/>
      <Setter Property="BorderRadius" Value="15"/>
      <Setter Property="BorderWidth" Value="1"/>
      <Setter Property="FontAttributes" Value="Bold" />
    </Style>
  

  我的按钮：

  <Button Text="Login" Command="{Binding LoginCommand}" Style="{DynamicResource buttonStyle}" />
  

  Xamarin Styles

  回复于 2024-04-24T03:22:13+08:00
• 1

  在Android中， RadiusProperty 仅停止与 AppCompat 一起工作known issue

  AppCompat

  如果要同时使用普通按钮和AppCompat，则需要从Button继承并注册 CustomRenderer .

  [assembly: ExportRenderer(typeof(RoundButton), typeof(RoundButtonRenderer))]
  namespace Project.Droid.Renderers
  {
      public class RoundButtonRenderer : Xamarin.Forms.Platform.Android.AppCompat.ButtonRenderer
      {
          ButtonDrawable _backgroundDrawable;
          Drawable _defaultDrawable;
          bool _drawableEnabled;
  
          protected override void Dispose(bool disposing)
          {
              if (disposing)
              {
                  if (_backgroundDrawable != null)
                  {
                      _backgroundDrawable.Dispose();
                      _backgroundDrawable = null;
                  }
              }
  
              base.Dispose(disposing);
          }
  
  
          protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.Button> e)
          {
              base.OnElementChanged(e);
  
              if (e.OldElement != null && _drawableEnabled)
              {
                  _drawableEnabled = false;
                  _backgroundDrawable.Reset();
                  _backgroundDrawable = null;
              }
              UpdateDrawable();
          }
  
  
  
          protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
          {
              if (_drawableEnabled &&
                  (e.PropertyName == VisualElement.BackgroundColorProperty.PropertyName || e.PropertyName == Xamarin.Forms.Button.BorderColorProperty.PropertyName || e.PropertyName == Xamarin.Forms.Button.BorderRadiusProperty.PropertyName ||
                  e.PropertyName == Xamarin.Forms.Button.BorderWidthProperty.PropertyName))
              {
                  _backgroundDrawable.Reset();
                  Control.Invalidate();
              }
  
              base.OnElementPropertyChanged(sender, e);
          }
  
          private void UpdateDrawable()
          {
              if (Element.BackgroundColor == Color.Default)
              {
                  if (!_drawableEnabled)
                      return;
  
                  if (_defaultDrawable != null)
                      Control.SetBackground(_defaultDrawable);
  
                  _drawableEnabled = false;
              }
              else
              {
                  if (_backgroundDrawable == null)
                      _backgroundDrawable = new ButtonDrawable();
  
                  _backgroundDrawable.Button = Element;
  
                  if (_drawableEnabled)
                      return;
  
                  if (_defaultDrawable == null)
                      _defaultDrawable = Control.Background;
  
                  Control.SetBackground(_backgroundDrawable.GetDrawable());
                  _drawableEnabled = true;
              }
  
              Control.Invalidate();
          }
      }
  
  
      public class ButtonDrawable : IDisposable
      {
          object _backgroundDrawable;
  
          PropertyInfo ButtonProperty;
          public Xamarin.Forms.Button Button
          {
              get
              {
                  return (Xamarin.Forms.Button)ButtonProperty.GetMethod.Invoke(_backgroundDrawable, null);
              }
              set
              {
                  ButtonProperty.SetMethod.Invoke(_backgroundDrawable, new object[] { value });
              }
          }
  
          public ButtonDrawable()
          {
              _backgroundDrawable = typeof(Xamarin.Forms.Platform.Android.ButtonRenderer).Assembly.CreateInstance("Xamarin.Forms.Platform.Android.ButtonDrawable");
              this.ResetMethod = _backgroundDrawable.GetType().GetMethod("Reset", BindingFlags.Instance | BindingFlags.Public);
              this.DisposeMethod = _backgroundDrawable.GetType().GetMethod("Dispose", BindingFlags.Instance | BindingFlags.Public);
              this.ButtonProperty = _backgroundDrawable.GetType().GetProperty("Button", BindingFlags.Instance | BindingFlags.Public);
          }
  
          MethodInfo ResetMethod;
          public void Reset()
          {
              ResetMethod.Invoke(_backgroundDrawable, null);
          }
  
          MethodInfo DisposeMethod;
          public void Dispose()
          {
              DisposeMethod.Invoke(_backgroundDrawable, null);
          }
  
          public Android.Graphics.Drawables.Drawable GetDrawable()
          {
              return _backgroundDrawable as Android.Graphics.Drawables.Drawable;
          }
      }
  }
  

  没有AppCompat

  如果你想删除AppCompat，你必须做两件事

  您的 MainActivity 必须现在从 global::Xamarin.Forms.Platform.Android.FormsApplicationActivity 继承，并且您的样式通常在 resources/values/styles.xml 中必须从非AppCompat样式继承，如 android:Theme.Material

  <resources>
    <!-- inherit from the material theme -->
    <style name="AppTheme" parent="android:Theme.Material">
      <!-- Main theme colors -->
      <!--   your app branding color for the app bar -->
      <item name="android:colorPrimary">@color/primary</item>
      <!--   darker variant for the status bar and contextual app bars -->
      <item name="android:colorPrimaryDark">@color/primary_dark</item>
      <!--   theme UI controls like checkboxes and text fields -->
      <item name="android:colorAccent">@color/accent</item>
    </style>
  </resources>
  

  回复于 2024-04-24T03:22:13+08:00
• 0

  在“内容页面”资源中创建样式，然后在按钮中添加此样式 . CornerRadius必须是HeightRequest和WidthRequest的一半 . 这适用于Xamarin.Forms> = 3.4 . 现在BorderRadius转换为CornerRadius .

  <ContentPage.Resources>
      <ResourceDictionary>
          <Style x:Key="myRoundbutton" TargetType="Button">
              <Setter Property="BackgroundColor" Value="Green"/>
              <Setter Property="TextColor" Value="White" />
              <Setter Property="BorderColor" Value="Blue"/>
               <Setter Property="CornerRadius" Value="35"/>
              <Setter Property="HeightRequest" Value="70" />
              <Setter Property="WidthRequest" Value="70"/>
              <Setter Property="BorderWidth" Value="2"/>
              <Setter Property="FontAttributes" Value="Bold" />
          </Style>
      </ResourceDictionary>
  </ContentPage.Resources>
  
  <ContentPage.Content>
        <StackLayout HorizontalOptions="Fill" 
                     VerticalOptions="Fill">
  
            <Button Image="myBtn3.png" 
                    Command="{Binding LoginCommand}" 
                    Style="{DynamicResource myRoundbutton}" />
  
        </StackLayout>
  </ContentPage.Content>
  

  回复于 2024-04-24T03:22:13+08:00