c# - 如何在 C# WPF 中通过拖放交换两个标签的数据？

Question

我想做类似的事情 我有两个标签

A .................. B
______ ............ ________
|红色 | ………… |绿色 |
------------ .......... ------------

当我将 A 拖到 B 或将 B 拖到 A 时，两者的文本交换

A .................. B
______ ...... ______
|绿色| ………… |红色 |
------------ .....................

我做了一点

主窗口

当我拖放代码中的文本时，会出现在放置标签上

当我在绿色上拖动红色时:

我的代码:

    private void Label_MouseDown(object sender, MouseButtonEventArgs e)
    {
        Label lblFrom = e.Source as Label;


        if (e.LeftButton == MouseButtonState.Pressed)
            DragDrop.DoDragDrop(lblFrom, lblFrom.Content, DragDropEffects.Copy);
    }

    private void Label_QueryContinueDrag(object sender, QueryContinueDragEventArgs e)
    {
        Label lblFrom = e.Source as Label;

        if (!e.KeyStates.HasFlag(DragDropKeyStates.LeftMouseButton))
            lblFrom.Content = "RED";

    }

    private void Label_Drop(object sender, DragEventArgs e)
    {
        string draggedText = (string)e.Data.GetData(DataFormats.StringFormat);

        Label toLabel = e.Source as Label;
        toLabel.Content = draggedText;
    }
}

Answer 1

这是我如何实现的。

下面是我的 XAML。

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>
    <Label Width="50" Height="50" Background="Red" Content="Red" HorizontalAlignment="Center" VerticalAlignment="Center" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" MouseDown="Label_MouseDown" Drop="Label_Drop" AllowDrop="True"/>
    <Label Width="50" Height="50" Background="Green" Content="Green" HorizontalAlignment="Center" VerticalAlignment="Center" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" Grid.Column="1" MouseDown="Label_MouseDown" Drop="Label_Drop" AllowDrop="True"/>
</Grid>

下面是我的代码隐藏事件

Label DraggingLabel;
private void Label_MouseDown(object sender, MouseButtonEventArgs e)
{
    DraggingLabel = sender as Label;
    if (e.LeftButton == MouseButtonState.Pressed)
        DragDrop.DoDragDrop(DraggingLabel, DraggingLabel.Content, DragDropEffects.Copy);
}

private void Label_Drop(object sender, DragEventArgs e)
{
    Label originalsource = e.OriginalSource as Label;
    Label lblToDrop = sender as Label;
    string fromContent = lblToDrop.Content.ToString();
    lblToDrop.Content = (string)e.Data.GetData(DataFormats.StringFormat);
    DraggingLabel.Content = fromContent;
}

所以基本上我创建了一个全局标签 DraggingLabel 以在 Label_Drop 处使用它来交换文本。

最终输出。

祝你好运。