国内有做网游评测的网站么,做网站的 简历,泉州微信网站开发,广州室内设计公司排名01—概述ObservableCollection继承了INotifyPropertyChanged接口#xff0c;在属性变更时可以通知界面#xff0c;当我把ObservableCollection集合绑定到界面的DataGrid后#xff0c;我希望在界面修改表格数值后#xff0c;可以触发一个 事件来验证我界面设定数据的有效性在属性变更时可以通知界面当我把ObservableCollection集合绑定到界面的DataGrid后我希望在界面修改表格数值后可以触发一个 事件来验证我界面设定数据的有效性但是对于集合的添加、删除只会触发集合的get属性值重置不会触发集合的get、set属性这时候我们就需要扩展ObservableCollection集合.02—集合扩展代码如下重写OnCollectionChanged方法使得集合改变(增添、删除、改变)时拥有属性变更事件using System;
using System.Collections;
using System.Collections.Specialized;
using System.ComponentModel;
using DevExpress.Xpo;namespace Caliburn.Micro.Hello
{public class ItemsChangeObservableCollectionT :System.Collections.ObjectModel.ObservableCollectionT where T : INotifyPropertyChanged{protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
{if (e.Action NotifyCollectionChangedAction.Add){RegisterPropertyChanged(e.NewItems);}else if (e.Action NotifyCollectionChangedAction.Remove){UnRegisterPropertyChanged(e.OldItems);}else if (e.Action NotifyCollectionChangedAction.Replace){UnRegisterPropertyChanged(e.OldItems);RegisterPropertyChanged(e.NewItems);}base.OnCollectionChanged(e);}protected override void ClearItems()
{UnRegisterPropertyChanged(this);base.ClearItems();}private void RegisterPropertyChanged(IList items)
{foreach (INotifyPropertyChanged item in items){if (item ! null){item.PropertyChanged new PropertyChangedEventHandler(item_PropertyChanged);}}}private void UnRegisterPropertyChanged(IList items)
{foreach (INotifyPropertyChanged item in items){if (item ! null){item.PropertyChanged - new PropertyChangedEventHandler(item_PropertyChanged);}}}private void item_PropertyChanged(object sender, PropertyChangedEventArgs e)
{//launch an event Reset with name of property changedbase.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));}}
}03—事件订阅可以用如下方法订阅事件this.StudentList.CollectionChanged StudentList_OnCollectionChanged;
或
StudentList.CollectionChanged new NotifyCollectionChangedEventHandler(StudentList_OnCollectionChanged);事件方法public void StudentList_OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e){MessageBox.Show(当前触发的事件是 e.Action.ToString());}集合定义private ItemsChangeObservableCollectionStudents studentList;public ItemsChangeObservableCollectionStudents StudentList{get{return studentList;}set{studentList value;}}04—效果演示源码下载网盘下载链接https://pan.baidu.com/s/1TD2BT5hiT-z-_7Z2Bn3PVQ提取码添加小编微信获取技术群添加小编微信并备注进群小编微信mm1552923 公众号dotNet编程大全
