我有一个ListBox
,我希望能够点击多个项目,然后从每个选择的项目中拖动字符串。我可以让它适用于单个对象。我只是不能让它工作超过1。
我看了WPF Drag & drop from ListBox with SelectionMode Multiple,但它完全让我感到难过(试图使用它,但它不起作用,我不理解它。)
我当前的Drag'n'Drop代码如下。
<ListBox.ItemContainerStyle>
<Style TargetType="{x:Type ListBoxItem}">
<EventSetter Event="MouseDoubleClick" Handler="ListBoxItemDClick"/>
<EventSetter Event="MouseDown" Handler="ReferenceList_PreviewMouseLeftButtonDown"/>
<EventSetter Event="MouseMove" Handler="ReferenceList_PreviewMouseMove"/>
<EventSetter Event="MouseUp" Handler="ReferenceListMouseUp"/>
<Style.Triggers>
...
</Style.Triggers>
</Style>
</ListBox.ItemContainerStyle>
Private Sub ListBoxItemDClick(sender As Object, e As MouseButtonEventArgs) 'DoubleClick
Dim PW As MainWindow = Window.GetWindow(MainPage)
If PW IsNot Nothing Then
Dim selite As ListBoxItem = DirectCast(ReferenceList.ItemContainerGenerator.ContainerFromItem(ReferenceList.SelectedItem), ListBoxItem)
PW.NewItem = False
PW.EditItem = ReferenceList.SelectedItem
PW.ChangeSlide(sender, 1)
End If
End Sub
Private Sub ReferenceList_PreviewMouseLeftButtonDown(sender As Object, e As MouseButtonEventArgs) 'Mouse Down on ListBoxItem
Dim PW As MainWindow = Window.GetWindow(MainPage)
StartPoint = e.GetPosition(Nothing)
PW.Resizing = False
End Sub
Private Sub ReferenceListMouseUp(sender As Object, e As MouseButtonEventArgs) 'Mouse Up on ListBoxItem
Dim PW As MainWindow = Window.GetWindow(MainPage)
StartPoint = e.GetPosition(Nothing)
PW.Resizing = True
End Sub
Private Sub ReferenceList_PreviewMouseMove(sender As Object, e As MouseEventArgs) 'MouseMove on ListBoxItem
Dim PW As MainWindow = Window.GetWindow(MainPage)
If PW.Resizing = False Then
If ReferenceList.SelectedItems.Count = 1 Then
Dim MousePosition As Point = e.GetPosition(Nothing)
Dim Difference As Vector = StartPoint - MousePosition
Dim StopDrop As Boolean = False
Dim LBITEM As ListBoxItem = DirectCast(sender, ListBoxItem)
If e.LeftButton = MouseButtonState.Pressed AndAlso (Math.Abs(Difference.X) > SystemParameters.MinimumHorizontalDragDistance Or Math.Abs(Difference.Y) > SystemParameters.MinimumVerticalDragDistance) Then
PW.TempItem = LBITEM.DataContext
Dim FN As String = PW.TempItem.PropLastName & ", " & PW.TempItem.PropFirstName.Substring(0, 1)
Dim TT As String = PW.TempItem.PropTitle
Dim YR As String = PW.TempItem.PropYear.ToString
Dim ReferenceText As String = FN & " " & YR & ", " & TT
Dim DragData As DataObject = New DataObject(DataFormats.StringFormat, ReferenceText)
If DragData IsNot Nothing And StopDrop = False Then
DragDrop.DoDragDrop(sender, DragData, DragDropEffects.Copy)
End If
End If
Else
Dim TotalReference As String = "Reference Data"
For Each ITEM As Object In ReferenceList.SelectedItems
Dim MousePosition As Point = e.GetPosition(Nothing)
Dim Difference As Vector = StartPoint - MousePosition
Dim StopDrop As Boolean = False
If e.LeftButton = MouseButtonState.Pressed AndAlso (Math.Abs(Difference.X) > SystemParameters.MinimumHorizontalDragDistance Or Math.Abs(Difference.Y) > SystemParameters.MinimumVerticalDragDistance) Then
PW.TempItem = ITEM
Dim FN As String = PW.TempItem.PropLastName & ", " & PW.TempItem.PropFirstName.Substring(0, 1)
Dim TT As String = PW.TempItem.PropTitle
Dim YR As String = PW.TempItem.PropYear.ToString
Dim ReferenceText As String = FN & " " & YR & ", " & TT
If TotalReference Is "Reference Data" Then
TotalReference = ReferenceText
Else
TotalReference = ReferenceText & vbCr & ReferenceText
End If
End If
Dim DragData As DataObject = New DataObject(DataFormats.StringFormat, TotalReference)
If DragData IsNot Nothing And StopDrop = False Then
DragDrop.DoDragDrop(sender, DragData, DragDropEffects.Copy)
End If
Next
End If
End If
End Sub
变量:
PW.Resizing (Boolean on MainWindow that determines whether window is resizing (True/False)
PW.TempItem (Declared on MainWindow as: Public TempItem as Reference 'Reference is my own class like a Student or such class to store data)
Private StartPoint As Point
ReferenceList is the ListBox containing all the ListBoxItems.
如果我需要提供更多详情,请告诉我。我不知道我的代码有多少被拖动的问题。
答案 0 :(得分:1)
没关系,我发现了我的错误。我替换了这一行:
TotalReference = ReferenceText & vbCr & ReferenceText
这一行:
TotalReference = TotalReference & vbCr & ReferenceText
现在一切正常!