C# 事件与继承

 

 

 

 

 

 

 

 

 

 

 在已有类中定义事件，为事件指定方法（虚方法A），子类中重写虚方法（重写方法A）B，那么在事件出发时，调用的是方法B。

 

 

 

 

 

public class

ClsBase

 

{

 

 

 

public delegate void BaseMethod(string

 

baseparam);

 

 

 

public event BaseMethod

ItemDeleting;

 

 

 

public

ClsBase()

{

ItemDeleting +=

 

 

new BaseMethod

(ClsBase_ItemDeleting);

ItemDeleting(

 

 

@"D:/foll/Test.txt"

);

}

 

 

 

protected virtual void ClsBase_ItemDeleting(string

baseparam)

{

 

 

 

if (File

.Exists(baseparam))

{

 

 

 

File

.Delete(baseparam);

}

}

}

 

 

 

 

public class ClsTest :

ClsBase

 

{

 

 

 

protected override void ClsBase_ItemDeleting(string

 

baseparam)

{

 

 

 

if (System.Windows.Forms.MessageBox.Show("Do you want to delete!"

,

 

 

 

"Demo", System.Windows.Forms.MessageBoxButtons.OKCancel) == System.Windows.Forms.DialogResult

.OK)

{

 

 

 

base

.ClsBase_ItemDeleting(baseparam);