如何以编程方式更改样式中的控件

Question

我有一个按钮样式。我无法更改"边界"的CornerRadius，这是"模板"中的内容。

样式：

<Style TargetType="Button" x:Key="Circle">
<Setter Property="Background" Value="#373737"/>
<Setter Property="SnapsToDevicePixels" Value="True" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Border Name="Bord1" CornerRadius="20" Background="{TemplateBinding Background}">
<Grid>
<TextBlock Name="tx" Text="{TemplateBinding Content}" HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="{TemplateBinding FontSize}" Foreground="White"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="#EBEBEB" />
<Setter TargetName="tx" Property="Foreground" Value="Black"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Background" >
<Setter.Value>
<LinearGradientBrush StartPoint="0,0" EndPoint="0,1" >
<GradientStop Color="#F3F3F3" Offset="0.35"/>
<GradientStop Color="#FFC9C7BA" Offset="0.95"/>
<GradientStop Color="#CDCDCD" Offset="1"/>
</LinearGradientBrush>
</Setter.Value>
</Setter>
<Setter TargetName="tx" Property="RenderTransform" >
<Setter.Value>
<TranslateTransform Y="1.0" />
</Setter.Value>
</Setter>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>

我写了这个代码，但对我没有帮助。

Style A = Application.Current.Resources["Circle"] as Style;
Setter A1 = (Setter)A.Setters[2];
ControlTemplate C1 = (ControlTemplate)A1.Value;
Border B = (Border)C1.LoadContent();
B.SetValue(Border.CornerRadiusProperty, new CornerRadius(2));

Answer 1

你可以这样使用你的风格：

将模板中的固定角半径更改为模板绑定

创建一个新类，如：

public class MyButton : Button {
public static readonly DependencyProperty CornerRadiusProperty = DependencyProperty.Register(
"CornerRadius", typeof(CornerRadius), typeof(MyButton), new PropertyMetadata(default(CornerRadius)));
public CornerRadius CornerRadius {
get { return (CornerRadius) GetValue(CornerRadiusProperty); }
set { SetValue(CornerRadiusProperty, value); }
}
}

在你的风格和xaml:中使用这样的类

<Window x:Class="WpfApp1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApp1"
mc:Ignorable="d"
Title="{Binding Path=Content.Title, ElementName=MainFrame}" Height="450" Width="800">
<Window.Resources>
<Style TargetType="local:MyButton" x:Key="Circle">
<Setter Property="Background" Value="#373737"/>
<Setter Property="SnapsToDevicePixels" Value="True" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="local:MyButton">
<Border Name="Bord1" CornerRadius="{TemplateBinding CornerRadius}" Background="{TemplateBinding Background}">
<Grid>
<TextBlock Name="tx" Text="{TemplateBinding Content}" HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="{TemplateBinding FontSize}" Foreground="White"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="#EBEBEB" />
<Setter TargetName="tx" Property="Foreground" Value="Black"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Background" >
<Setter.Value>
<LinearGradientBrush StartPoint="0,0" EndPoint="0,1" >
<GradientStop Color="#F3F3F3" Offset="0.35"/>
<GradientStop Color="#FFC9C7BA" Offset="0.95"/>
<GradientStop Color="#CDCDCD" Offset="1"/>
</LinearGradientBrush>
</Setter.Value>
</Setter>
<Setter TargetName="tx" Property="RenderTransform" >
<Setter.Value>
<TranslateTransform Y="1.0" />
</Setter.Value>
</Setter>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<StackPanel>
<local:MyButton Style="{StaticResource Circle}" CornerRadius="10"></local:MyButton>
</StackPanel>
</Window>

更新：

或者，您可以通过程序更改边界的CornerRadius，如：

public partial class MainWindow : Window {
public MainWindow() {
InitializeComponent();
Loaded += WasLoaded;
}
private void WasLoaded(object sender, RoutedEventArgs e) {
var children = VisualTreeHelper.GetChildrenRecursive(Button1);
foreach (var child in children.OfType<Border>()) {
if (child.Name == "Bord1") {
child.CornerRadius = new CornerRadius(1);
break;
}
}
}
}
public static class VisualTreeHelper {
/// <summary>
/// Enumerates through element's children in the visual tree.
/// </summary>
public static IEnumerable<DependencyObject> GetChildrenRecursive(this DependencyObject element) {
if (element == null) {
throw new ArgumentNullException("element");
}
for (var i = 0; i < System.Windows.Media.VisualTreeHelper.GetChildrenCount(element); i++) {
var child = System.Windows.Media.VisualTreeHelper.GetChild(element, i);
yield return child;
foreach (var item in child.GetChildrenRecursive()) {
yield return item;
}
}
}
}