按下鼠标左键时更改鼠标光标？

Question

我需要在按下鼠标左键时更改鼠标光标。不幸的是，在释放鼠标左键之前，鼠标光标的更改将被忽略。有什么解决方法吗？感谢您的任何提示！

（我正在使用 WPF 和 C#）

编辑：

示例项目： http://cid-0432ee4cfe9c26a0.skydrive.live .com/self.aspx/%c3%96ffentlich/WpfApplication5.zip （只需运行它，说明会显示在应用程序中）

示例代码：

XAML：

<Window x:Class="WpfApplication5.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="695" Loaded="Window_Loaded">
<Grid>
    <Button Content="Button1" Height="287" HorizontalAlignment="Left" Margin="12,12,0,0" Name="button1" VerticalAlignment="Top" Width="235" />
    <Button Content="Button2" Height="287" HorizontalAlignment="Left" Margin="284,12,0,0" Name="button2" VerticalAlignment="Top" Width="278" MouseMove="button2_MouseMove" />
</Grid>

窗类：

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void button2_MouseMove(object sender, MouseEventArgs e)
    {
        Cursor = Cursors.Cross;
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        button1.Content="Step1: Left click on this button, \nhold down the left mouse button";
        button2.Content = "(Make sure you don't hover this\n button before hovering Button1.\n Default application cursor\n is the normal arrow cursor)\n\n Step 2: Keep on holding the left mouse \nbutton, hover this button\n\nThe cursor won't change. (It will change after the \nleft mouse button was released)";
    }
}

Answer 1

我建议尽可能使用 Preview* 事件来进行视觉更改，因为它将使您的逻辑很好地分离。另外，最好（恕我直言）使用Mouse.OverrideCursor属性来临时更改光标。

例如：

void Window_Loaded(object sender, RoutedEventArgs e)
{
    // ...
    button1.PreviewMouseLeftButtonDown += Button1_PreviewMouseLeftButtonDown;
    button1.PreviewMouseLeftButtonUp += Button1_PreviewMouseLeftButtonUp;
}

void Button1_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    Mouse.OverrideCursor = Cursors.Cross;
    Mouse.Capture(button1);
}

void Button1_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
    Mouse.Capture(null);
    Mouse.OverrideCursor = null;
}

Answer 2

在鼠标左键按下处理程序中，您可以有以下代码。

try
{
   Cursor = Cursors.WaitCursor;
}
catch(Exception ex)
{
}
finally
{
   Cursor = Cursors.Default;
}

您可以根据您的要求重置为默认光标。