[英]UWP drag and drop custom type/class
我在那里,我试图在2个GridView之间进行拖放,我设法用“DataPackage”类的自定义类型(SetText,SetBitmap等)来做,但我无法弄清楚怎么做这与自定义类/类型。 两个GridView都绑定到同一个自定义类(只有几个属性,int,string,bitmapimage),我只是想将这些数据项从一个GridView直接拖到另一个。 非常感谢您的帮助!
因此,为了总结其他人的好处,我将这些添加到DataTemplate内容的事件处理程序中,因为我只希望某个(ViewModel)类型的项可以拖动。
private void Grid_Drop(object sender, DragEventArgs e)
{
if (sender is FrameworkElement)
{
var fe = sender as FrameworkElement;
var targetIvm = fe.DataContext as ItemViewModel;
object obj = null;
if(e.DataView.Properties.TryGetValue("ItemViewModel", out obj))
{
var sourceIvm = obj as ItemViewModel;
vm.MoveItem(sourceIvm, targetIvm);
}
}
}
private void Grid_DragStarting(Windows.UI.Xaml.UIElement sender, DragStartingEventArgs args)
{
if (sender is FrameworkElement)
{
var fe = sender as FrameworkElement;
var item = new KeyValuePair<string, object>("ItemViewModel", fe.DataContext);
args.Data.RequestedOperation = DataPackageOperation.Move;
args.Data.Properties.Add("ItemViewModel", fe.DataContext);
}
}
我有同样的问题,请检查这个例子我使用了Behaviors,因为我使用了MVVM模式,但是我为ListView做了这个,但对于GridView只做了很小的改动。
将行为<ListView>
更改为<GridView>
此行为附加在ListView中您要拖动项目
public class StartingDragBehavior:Behavior<ListView>
{
protected override void OnAttached()
{
base.OnAttached();
this.AssociatedObject.CanDragItems = true;
this.AssociatedObject.DragItemsStarting += AssociatedObject_DragItemsStarting;
}
private void AssociatedObject_DragItemsStarting(object sender, DragItemsStartingEventArgs e)
{
e.Data.RequestedOperation = Windows.ApplicationModel.DataTransfer.DataPackageOperation.Copy;
if(e.Items!=null && e.Items.Any())
{
e.Data.Properties.Add("item", e.Items.FirstOrDefault());
}
}
protected override void OnDetaching()
{
base.OnDetaching();
this.AssociatedObject.DragItemsStarting -= AssociatedObject_DragItemsStarting;
}
}
此行为附加在ListView中您要删除项目这里另一个行为来捕获drop事件。
public class EndDropBehavior : Behavior<ListView>
{
protected override void OnAttached()
{
base.OnAttached();
this.AssociatedObject.AllowDrop = true;
this.AssociatedObject.Drop += AssociatedObject_Drop;
this.AssociatedObject.DragOver += AssociatedObject_DragOver;
}
private void AssociatedObject_Drop(object sender, Windows.UI.Xaml.DragEventArgs e)
{
if (e.DataView != null &&
e.DataView.Properties != null &&
e.DataView.Properties.Any(x => x.Key == "item" && x.Value.GetType() == typeof(MyObject)))
{
try
{
var def = e.GetDeferral();
var item = e.Data.Properties.FirstOrDefault(x => x.Key == "item");
var card = item.Value as MyObject;
var list = sender as ListView;
var vm = list.DataContext as Infrastructure.ViewModels.CreditCardsViewModel;
vm.MyCollection.Add(card);
def.Complete();
}
catch (Exception ex)
{
Debug.WriteLine(ex.ToString());
}
}
else
{
e.AcceptedOperation = Windows.ApplicationModel.DataTransfer.DataPackageOperation.None;
}
}
private void AssociatedObject_DragOver(object sender, Windows.UI.Xaml.DragEventArgs e)
{
if (e.DataView != null &&
e.DataView.Properties != null &&
e.DataView.Properties.Any(x => x.Key == "item" && x.Value.GetType() == typeof(MyObject)))
{
e.AcceptedOperation = e.AcceptedOperation = Windows.ApplicationModel.DataTransfer.DataPackageOperation.Copy;
}
else
{
e.AcceptedOperation = Windows.ApplicationModel.DataTransfer.DataPackageOperation.None;
}
}
protected override void OnDetaching()
{
base.OnDetaching();
this.AssociatedObject.Drop -= AssociatedObject_Drop;
this.AssociatedObject.DragOver -= AssociatedObject_DragOver;
}
}
如果您不使用MVVM模式,只需检查“行为”的事件。
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