在WPF中给Canvas上的文字添加点击才会出现的边框并可以通过鼠标拖动边框改变控件大小,该文字控件是通过点击按钮动态添加的
时间: 2024-03-01 09:52:22 浏览: 32
可以通过以下步骤来实现在WPF中给Canvas上的文字添加点击时出现边框并可以通过鼠标拖动边框改变控件大小的效果:
1. 在XAML文件中,添加一个Canvas控件和一个Button控件,用于动态添加TextBlock控件:
```xaml
<Canvas x:Name="canvas" Background="White" MouseUp="Canvas_MouseUp">
<!-- 这里可以添加已经存在的TextBlock控件 -->
</Canvas>
<Button Content="Add TextBlock" Click="Button_Click" />
```
2. 在Button的Click事件中,动态添加TextBlock控件,并为其添加MouseDown、MouseUp、MouseMove事件:
```csharp
private void Button_Click(object sender, RoutedEventArgs e)
{
// 创建TextBlock控件,并为其设置一些属性
TextBlock textBlock = new TextBlock();
textBlock.Text = "Hello, world!";
textBlock.Foreground = Brushes.Black;
textBlock.FontSize = 16;
// 设置TextBlock控件的位置和大小
Canvas.SetLeft(textBlock, 50);
Canvas.SetTop(textBlock, 50);
textBlock.Width = 100;
textBlock.Height = 50;
// 为TextBlock控件添加MouseDown、MouseUp、MouseMove事件
textBlock.MouseDown += TextBlock_MouseDown;
textBlock.MouseUp += TextBlock_MouseUp;
textBlock.MouseMove += TextBlock_MouseMove;
// 将TextBlock控件添加到Canvas控件中
canvas.Children.Add(textBlock);
}
```
3. 在TextBlock的MouseDown事件中,创建一个边框控件,并将其添加到Canvas上,同时将TextBlock控件的位置和大小赋值给边框控件:
```csharp
private void TextBlock_MouseDown(object sender, MouseButtonEventArgs e)
{
// 创建边框控件
Border border = new Border();
border.BorderBrush = Brushes.Black;
border.BorderThickness = new Thickness(1);
border.Background = Brushes.Transparent;
// 获取当前点击的TextBlock控件
TextBlock textBlock = sender as TextBlock;
// 获取TextBlock控件的位置和大小,并设置给边框控件
double left = Canvas.GetLeft(textBlock);
double top = Canvas.GetTop(textBlock);
double width = textBlock.ActualWidth;
double height = textBlock.ActualHeight;
border.Width = width;
border.Height = height;
Canvas.SetLeft(border, left);
Canvas.SetTop(border, top);
// 将边框控件添加到Canvas控件中
canvas.Children.Add(border);
}
```
4. 在TextBlock的MouseUp事件中,移除边框控件:
```csharp
private void TextBlock_MouseUp(object sender, MouseButtonEventArgs e)
{
// 获取当前点击的TextBlock控件
TextBlock textBlock = sender as TextBlock;
// 移除边框控件
foreach (UIElement element in canvas.Children)
{
if (element is Border)
{
Border border = element as Border;
if (border.Tag == textBlock)
{
canvas.Children.Remove(border);
break;
}
}
}
}
```
5. 在TextBlock的MouseMove事件中,更新边框控件的位置和大小:
```csharp
private void TextBlock_MouseMove(object sender, MouseEventArgs e)
{
// 获取当前点击的TextBlock控件
TextBlock textBlock = sender as TextBlock;
// 查找对应的边框控件
Border border = null;
foreach (UIElement element in canvas.Children)
{
if (element is Border)
{
Border temp = element as Border;
if (temp.Tag == textBlock)
{
border = temp;
break;
}
}
}
// 如果找到了对应的边框控件,则更新其位置和大小
if (border != null)
{
double left = Canvas.GetLeft(textBlock);
double top = Canvas.GetTop(textBlock);
double width = textBlock.ActualWidth;
double height = textBlock.ActualHeight;
border.Width = width;
border.Height = height;
Canvas.SetLeft(border, left);
Canvas.SetTop(border, top);
}
}
```
这样,当用户点击TextBlock控件时,就会在其周围创建一个边框控件,可以通过鼠标拖动边框改变TextBlock控件的位置和大小。同时,当用户松开鼠标时,边框控件会被移除。
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