| 标题 | 河南省德威钢结构工程有限 |
| 内容 | 代码，内含说明（界面是两个文本框textbox1，textbox2，和一个button1，界面的Load事件，button的click事件） using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace Test { public partial class Form1 : Form { public Form1() { InitializeComponent(); } //CustomClass cc = new CustomClass(1, "Lee");//测试属性值不变化的情况 CustomClass cc = new CustomClass();//空构造函数，一边测试属性值改变 private void Form1_Load(object sender, EventArgs e) { cc.Changed += new CustomClass.ChangedEventHandler(cc_Changed);//加载事件 } private void button1_Click(object sender, EventArgs e) { cc.Cid = 1; cc.Cname = "Lee";//给CustomClass的属性赋值，赋值是引发事件 string str = cc.Cid.ToString() + cc.Cname; MessageBox.Show(str); } private void cc_Changed()//事件 { textBox1.Text = cc.Cid.ToString(); textBox2.Text = cc.Cname; } } public class CustomClass { public delegate void ChangedEventHandler();//定义委托 public event ChangedEventHandler Changed;//定义事件 private int _Cid; private string _Cname; public CustomClass() { } public CustomClass(int cCid, string cCname) { this._Cid = cCid; this._Cname = cCname; } protected virtual void OnChanged() { if (Changed!=null) { Changed(); } } public int Cid { get { return _Cid; } set { if (_Cid!=value)//这里是文本改变时的处理 { _Cid = value; OnChanged();//启动事件 } } } public string Cname { get { return _Cname; } set { if (_Cname != value) { _Cname = value; OnChanged(); } } } } } 以下是网上的一段非常经典的属性值改变引发自定义事件的例子，如下; public class MyClass { public event EventHandler<PropertyChagedEventArgs> MyPropertyChanging; public event EventHandler<PropertyChagedEventArgs> MyPropertyChanged; private int _myProperty; public int MyProperty { get { return _myProperty; } set { if (value != _myProperty) { PropertyChagedEventArgs e = new PropertyChagedEventArgs("MyProperty", _myProperty, value);//初始化 if (this.MyPropertyChanging != null) { this.MyPropertyChanging(this, e); if (e.Cancel) return; } _myProperty = (int)e.NewValue; if (this.MyPropertyChanged != null) { this.MyPropertyChanged(this, e); } } } } } /// <summary> /// 通用的类 /// </summary> public class PropertyChagedEventArgs : EventArgs { public PropertyChagedEventArgs(string propertyName,object oldValue,object newValue) { PropertyName = propertyName; OldValue = oldValue; NewValue = newValue; } public bool Cancel { get; set; } public string PropertyName { get; private set; } public object OldValue { get; private set; } public object NewValue { get; set; } } |
| 随便看 |
|
在线学习网考试资料包含高考、自考、专升本考试、人事考试、公务员考试、大学生村官考试、特岗教师招聘考试、事业单位招聘考试、企业人才招聘、银行招聘、教师招聘、农村信用社招聘、各类资格证书考试等各类考试资料。