今天我一直在砸桌子,试图触发拖放事件。拖放功能可在界面上使用,但事件不会触发。我需要触发事件,以便可以使用对象的新顺序更新数据库。我在做什么错了?
在下面的代码中,我在'Drop'和'DragOver'方法中放置了断点,但是它们从未被命中。
XAML:
<Window x:Class="Reorder_item_WPF.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525"
xmlns:dd="clr-namespace:GongSolutions.Wpf.DragDrop;assembly=GongSolutions.Wpf.DragDrop">
<Grid>
<ListBox Grid.Column="1" SelectionMode="Extended" ItemsSource="{Binding MSPCollection}"
dd:DragDrop.IsDragSource="True" Width="300" Margin="0,0,5,0" dd:DragDrop.IsDropTarget="True">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Background="#2ba3d5" Height="50" Width="280">
<TextBlock Text="{Binding Name}" Foreground="White" HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="40"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</Window>
c#:
public class MSP {
public int Id { get; set; }
public string Name { get; set; }
}
class MainViewModel : IDropTarget
{
public ObservableCollection<MSP> MSPCollection { get; set; }
public MainViewModel() {
MSPCollection = new ObservableCollection<MSP>();
MSPCollection.Add(new MSP() {
Id = 1,
Name = "Anis Derbel"
});
MSPCollection.Add(new MSP()
{
Id = 2,
Name = "Firas Mdimagh"
});
MSPCollection.Add(new MSP()
{
Id = 3,
Name = "Khaled Jemni"
});
MSPCollection.Add(new MSP()
{
Id = 4,
Name = "Sahbouch"
});
}
public void DragOver(IDropInfo dropInfo) {
if (dropInfo.Data is MSP) {
dropInfo.DropTargetAdorner = DropTargetAdorners.Highlight;
dropInfo.Effects = DragDropEffects.Move;
}
}
public void Drop(IDropInfo dropInfo) {
MSP msp = (MSP)dropInfo.Data;
((IList)dropInfo.DragInfo.SourceCollection).Remove(msp);
}
}
答案 0 :(得分:1)
您还需要通过相应的附加属性设置DropHandler:
<ListBox ItemsSource="{Binding Collection}"
dd:DragDrop.IsDragSource="True"
dd:DragDrop.IsDropTarget="True"
dd:DragDrop.DropHandler="{Binding}" />