wpf - 是否可以在 wpf 的选项卡控件中重新排列选项卡项？

Question

是否可以在运行时重新排列选项卡控件中的选项卡项？例如，我有 3 个关于汽车的标签项目和 4 个关于房子的标签。我希望能够使用拖放重新排列它们。有可能还是太棒了？

我在这里有选项卡控件是 XAML。

<TabControl x:Name="tc" Visibility="Collapsed" GotFocus="Focus" AllowDrop="True" >
            </TabControl>

选项卡项将在运行时添加。谢谢你帮助我！

Answer 1

在 MSDN 论坛中找到了解决方案。

链接在这里：

拖放选项卡项

这是解决方案：

C# 解决方案

WPF代码：

<TabControl>
    <TabControl.Resources>
        <Style TargetType="TabItem">
            <Setter Property="AllowDrop" Value="True"/>
                <EventSetter Event="PreviewMouseMove" Handler="TabItem_PreviewMouseMove"/>
                <EventSetter Event="Drop" Handler="TabItem_Drop"/>
        </Style>
    </TabControl.Resources>

    <TabItem Header="Tabitem 1"/>
    <TabItem Header="Tabitem 2"/>
    <TabItem Header="Tabitem 3"/>
    <TabItem Header="Tabitem 4"/>
    <TabItem Header="Tabitem 5"/>
</TabControl>

后面的 C# 代码：

private void TabItem_PreviewMouseMove(object sender, MouseEventArgs e)
{
    if (!(e.Source is TabItem tabItem))
    {
        return;
    }

    if (Mouse.PrimaryDevice.LeftButton == MouseButtonState.Pressed)
    {
        DragDrop.DoDragDrop(tabItem, tabItem, DragDropEffects.All);
    }
}

private void TabItem_Drop(object sender, DragEventArgs e)
{
    if (e.Source is TabItem tabItemTarget &&
        e.Data.GetData(typeof(TabItem)) is TabItem tabItemSource &&
        !tabItemTarget.Equals(tabItemSource) &&
        tabItemTarget.Parent is TabControl tabControl)
    {
        int targetIndex = tabControl.Items.IndexOf(tabItemTarget);

        tabControl.Items.Remove(tabItemSource);
        tabControl.Items.Insert(targetIndex, tabItemSource);
        tabItemSource.IsSelected = true;
    }
}

Answer 2

当我尝试实现此解决方案时，drop 事件触发了两次（移动选项卡但它们立即将它们移回）。我必须添加一个整数来跟踪最后一个选项卡目标索引。我的解决方案是在 VB.NET

'additional variable
Dim lastTabTargetIndex As Integer = Nothing

Private Sub tc1_PreviewMouseMove(sender As Object, e As MouseEventArgs) Handles tc1.PreviewMouseMove

    Dim Tabi = TryCast(e.Source, TabItem)

    If Tabi Is Nothing Then
        Exit Sub
    Else
        If Mouse.PrimaryDevice.LeftButton = MouseButtonState.Pressed Then
            DragDrop.DoDragDrop(Tabi, Tabi, DragDropEffects.All)
        End If
    End If
End Sub

Private Sub tc1_Drop(sender As Object, e As DragEventArgs) Handles tc1.Drop

    Dim tabItemTarget = TryCast(e.Source, TabItem)
    Dim tabItemSource = TryCast(e.Data.GetData(GetType(TabItem)), TabItem)

    If Not tabItemTarget.Equals(tabItemSource) Then
        Dim tabControl = TryCast(tabItemTarget.Parent, TabControl)
        Dim sourceIndex As Integer = tabControl.Items.IndexOf(tabItemSource)
        Dim targetIndex As Integer = tabControl.Items.IndexOf(tabItemTarget)

        'had to use this extra statement
        If sourceIndex <> lastTabTargetIndex Then
            'assign lastTabTargetIndex here
            lastTabTargetIndex = targetIndex
            tabControl.Items.Remove(tabItemSource)
            tabControl.Items.Insert(targetIndex, tabItemSource)
            tabControl.Items.Remove(tabItemTarget)
            tabControl.Items.Insert(sourceIndex, tabItemTarget)
        End If

    End If
End Sub