Question

我想在WPF中创建一个“Hello World”。这是我的XAML：

<Grid>
    <TextBlock HorizontalAlignment="Center" TextWrapping="Wrap" Text="Hello, WPF" VerticalAlignment="Center" FontSize="60" MouseEnter="TextBlock_MouseEnter" MouseLeave="TextBlock_MouseLeave"/>

</Grid>

...和我的代码隐藏：

 private void TextBlock_MouseEnter(object sender, MouseEventArgs e)
    {
        this.FontSize = 90;
    }

    private void TextBlock_MouseLeave(object sender, MouseEventArgs e)
    {
        this.FontSize = 72;
    }

当我将鼠标移到TextBlock时，字体应该设置为更大的尺寸，而在MouseLeave上它应该设置为更小的尺寸。

但是，字体大小不变。处理程序被成功调用，为什么字体大小不会改变？

Answer 1

为您的TextBlock命名并影响新的FontSize

<Grid>
        <TextBlock Name="Tb" HorizontalAlignment="Center" TextWrapping="Wrap" Text="Hello, WPF" VerticalAlignment="Center" FontSize="60" MouseEnter="TextBlock_MouseEnter" MouseLeave="TextBlock_MouseLeave"/>        
</Grid>

和背后的代码

  private void TextBlock_MouseEnter(object sender, MouseEventArgs e)
    {
        Tb.FontSize = 90;
    }

    private void TextBlock_MouseLeave(object sender, MouseEventArgs e)
    {
        Tb.FontSize = 72;
    }

更好的解决方案

更好的解决方案是使用Trigger，不需要事件处理程序

<TextBlock  HorizontalAlignment="Center" TextWrapping="Wrap" Text="Hello, WPF" VerticalAlignment="Center" >
        <TextBlock.Style>
            <Style TargetType="TextBlock">
                <Style.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter Property="FontSize" Value="90"></Setter>
                    </Trigger>
                    <Trigger Property="IsMouseOver" Value="False">
                        <Setter Property="FontSize" Value="72"></Setter>
                    </Trigger>
                </Style.Triggers>
            </Style>
        </TextBlock.Style>
    </TextBlock>

Answer 2

你必须从这样的对象中获取textBlock。在这种情况下，您不需要TextBlock的名称。

private void TextBlock_MouseEnter(object sender, MouseEventArgs e)
    {
       var block = sender as TextBlock;
       block.FontSize = 90;
    }

private void TextBlock_MouseLeave(object sender, MouseEventArgs e)
    {
      var block = sender as TextBlock;
      block.FontSize = 72;
    }

WPF字体大小不变

2 个答案: