问题描述

我正在尝试使用 MVVM 编写拖放功能，这将允许我将 PersonModel 对象从一个 ListView 拖到另一个.

I am trying write Drag and Drop functionality using MVVM which will allow me to drag PersonModel objects from one ListView to another.

这几乎可以工作，但我需要能够从 DragEventArgs 中获取源 ListView 的 ItemsSource，但我不知道该怎么做.

This is almost working but I need to be able to get the ItemsSource of the source ListView from the DragEventArgs which I cant figure out how to do.

private void OnHandleDrop(DragEventArgs e)
{
    if (e.Data != null && e.Data.GetDataPresent("myFormat"))
    {
        var person = e.Data.GetData("myFormat") as PersonModel;
        //Gets the ItemsSource of the source ListView
        ..

        //Gets the ItemsSource of the target ListView and Adds the person to it
        ((ObservableCollection<PersonModel>)(((ListView)e.Source).ItemsSource)).Add(person);
    }
}

任何帮助将不胜感激.

谢谢！

推荐答案

我在另一个问题中找到了答案

这样做的方法是将源ListView传递给DragDrow.DoDragDrop方法即.

The way to do it is to pass the source ListView into the DragDrow.DoDragDrop method ie.

在处理ListView的PreviewMouseMove的方法中做-

In the method which handles the PreviewMouseMove for the ListView do-

private static void List_MouseMove(MouseEventArgs e)
{
    if (e.LeftButton == MouseButtonState.Pressed)
    {
        if (e.Source != null)
        {
            DragDrop.DoDragDrop((ListView)e.Source, (ListView)e.Source, DragDropEffects.Move);
        }
    }
}

然后在 OnHandleDrop 方法中将代码改为

and then in the OnHandleDrop method change the code to

private static void OnHandleDrop(DragEventArgs e)
{
    if (e.Data != null && e.Data.GetDataPresent("System.Windows.Controls.ListView"))
    {
        //var person = e.Data.GetData("myFormat") as PersonModel;
        //Gets the ItemsSource of the source ListView and removes the person
        var source = e.Data.GetData("System.Windows.Controls.ListView") as ListView;
        if (source != null)
        {
            var person = source.SelectedItem as PersonModel;
            ((ObservableCollection<PersonModel>)source.ItemsSource).Remove(person);

            //Gets the ItemsSource of the target ListView
            ((ObservableCollection<PersonModel>)(((ListView)e.Source).ItemsSource)).Add(person);
        }
    }
}

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