本文實例為大家分享了C#屬性改變引發(fā)事件示例的具體代碼，供大家參考，具體內(nèi)容如下
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication15
{
class Program
{
static void Main(string[] args)
{
Monitor m = new Monitor();
m.PropertyChanging += new Monitor.EventHandler(m_PropertyChanging);
m.Year = 2014;
m.Year = 1890;
m.Year = 2013;
}
static bool First=false;
static void m_PropertyChanging(object sender, PropertyChangingEventArgs e)
{
if (First==false)
{
First = true;
}
else
{
if (e.NewValue < 1900 || e.NewValue > 3000)
e.Cancel = true;
}
}
}
//（屬性正在改變的時候）事件數(shù)據(jù)
class PropertyChangingEventArgs : EventArgs
{
//構(gòu)造函數(shù)
public PropertyChangingEventArgs(string PropertyName, int OldValue, int NewValue)
{
_PropertyName = PropertyName;
_OldValue = OldValue;
_NewValue = NewValue;
}
//存儲數(shù)據(jù)
private string _PropertyName;
private int _OldValue;
private int _NewValue;
private bool _Cancel;
//獲取或設(shè)置屬性
public string PropertyName
{
set
{
_PropertyName = value;
}
get
{
return _PropertyName;
}
}
public int OldValue
{
set
{
_OldValue = value;
}
get
{
return _OldValue;
}
}
public int NewValue
{
set
{
_NewValue = value;
}
get
{
return _NewValue;
}
}
public bool Cancel
{
set
{
_Cancel = value;
}
get
{
return _Cancel;
}
}
}
class Monitor
{
//定義委托
public delegate void EventHandler(object sender, PropertyChangingEventArgs e);
//定義事件
public event EventHandler PropertyChanging;
//事件處理（用屬性方法）
int _YearValue;
public int Year
{
get
{
return _YearValue;
}
set
{
if (_YearValue != value)
{
if (PropertyChanging != null)
{
PropertyChangingEventArgs e = new PropertyChangingEventArgs("Year", _YearValue, value);
PropertyChanging(this, e);
if (e.Cancel)
{
return;
}
else
{
_YearValue = value;
}
}
}
}
}
}
}
以上就是本文的全部內(nèi)容，希望對大家的學習有所幫助，也希望大家多多支持html5模板網(wǎng)。
【網(wǎng)站聲明】本站部分內(nèi)容來源于互聯(lián)網(wǎng),旨在幫助大家更快的解決問題，如果有圖片或者內(nèi)容侵犯了您的權(quán)益，請聯(lián)系我們刪除處理，感謝您的支持！