WPF：在ListView中添加项目时提高事件 [英] WPF: Raise an Event when Item is added in ListView

问题描述

我正在使用WPF，而且我正在使用ListView，当我添加一个项目时，我需要触发一个事件。我已经尝试过：

  var dependencyPropertyDescriptor = DependencyPropertyDescriptor.FromProperty（ItemsControl.ItemsSourceProperty，typeof（ListView））; 
 if（dependencyPropertyDescriptor！= null）
 {
 dependencyPropertyDescriptor.AddValueChanged（this，ItemsSourcePropertyChangedCallback）; 
} 
  

.....

  private void ItemsSourcePropertyChangedCallback（object sender，EventArgs e）
 {
 RaiseItemsSourcePropertyChangedEvent（）; 
} 
  

但是，只有当整个集合更改时，阅读这篇文章：事件触发 - when-item-is-added- to-listview ，但最佳答案仅适用于列表框。我试图将代码更改为ListView，但我无法做到这一点。

希望你能帮助我。谢谢你提前。

解决方案

注意这只适用于WPF Listview！

经过一些研究，我找到了我的问题的答案，这很简单：

  public MyControl（）
 {
 InitializeComponent（）; 
（（INotifyCollectionChanged）listView.Items）.CollectionChanged + = ListView_CollectionChanged; 
} 
 
 private void ListView_CollectionChanged（object sender，NotifyCollectionChangedEventArgs e）
 {
 if（e.Action == NotifyCollectionChangedAction.Add）
 {
 //将新项目滚动到视图
 listView.ScrollIntoView（e.NewItems [0]）; 
} 
} 
  

其实， NotifyCollectionChangedAction 枚举允许您的程序通知您有任何更改，如：添加，移动，替换，删除和重置。

I am working on WPF and I am using a ListView, and I need to fire an event when an item is added to it. I have tried this:

var dependencyPropertyDescriptor = DependencyPropertyDescriptor.FromProperty(ItemsControl.ItemsSourceProperty, typeof(ListView));
        if (dependencyPropertyDescriptor != null)
        {
               dependencyPropertyDescriptor.AddValueChanged(this, ItemsSourcePropertyChangedCallback);
        }

.....

 private void ItemsSourcePropertyChangedCallback(object sender, EventArgs e)
    {
         RaiseItemsSourcePropertyChangedEvent();
    }

But It seems to be working only when the entire collection is changed, I have read this post: event-fired-when-item-is-added-to-listview, but the best answer applies for a listBox only. I tried to change the code to ListView but I wasnt able to do that.

I hope You can help me. Thank you in advance.

解决方案

Note this only works for a WPF Listview!

After some research I have found the answer to my question and It's really easy:

public MyControl()
{
    InitializeComponent();
    ((INotifyCollectionChanged)listView.Items).CollectionChanged +=  ListView_CollectionChanged;
}

private void ListView_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)     
{
    if (e.Action == NotifyCollectionChangedAction.Add)
    {
      // scroll the new item into view   
      listView.ScrollIntoView(e.NewItems[0]);
    }
}

Actually, the NotifyCollectionChangedAction enum allows your program to inform you about any change such as: Add, Move, Replace, Remove and Reset.

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