mahapps.metro - mahapps SplitButton 单击展开

Question

我在 WPF(C#) 中定义了一个带有绑定(bind)项源的 SplitButton。

只有当用户单击 SplitButton 右侧的箭头时，项目列表才会展开。

当用户点击SplitButton区域时如何展开列表？

我尝试处理点击事件并设置属性IsExpanded=true，但一秒后它自动消失。

<Controls:SplitButton Name="SplitButton_Test"
              Width="100"
              HorizontalAlignment="Left"
              HorizontalContentAlignment="Left"
              ItemsSource="{Binding Dictionary_Test}"
              DisplayMemberPath="Value"
              SelectedValuePath="Key"
              Click="Test_Click">
    <Controls:SplitButton.Icon>
        <iconPacks:PackIconMaterial Margin="6" Kind="Alert" />
    </Controls:SplitButton.Icon>
</Controls:SplitButton>

private void Test_Click(object sender, RoutedEventArgs e)
{
    if (SplitButton_Test.IsExpanded == false)
    {
        e.Handled = true;
        SplitButton_Test.IsExpanded = true; //Doesn't work, closes automatically after 1 second
    }
}

Answer 1

MahApps 中的这段代码正在关闭它:

 //Make popup close even if no selectionchanged event fired (case when user select the save item as before)
    void ListBoxPreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        var item = ContainerFromElement(_listBox, e.OriginalSource as DependencyObject) as ListBoxItem;
        if (item != null)
        {
            IsExpanded = false;
        }
    }

目前位于 https://github.com/MahApps/MahApps.Metro/blob/develop/src/MahApps.Metro/MahApps.Metro.Shared/Controls/SplitButton.cs#L339

您需要删除该事件处理程序。如何？这完全是另一个问题。