【发布时间】:2011-12-02 21:57:32
【问题描述】:
我正在尝试订阅用户控件的保存按钮事件,该用户控件在与调用父级不同的 radwindow 中启动。但我收到对象未初始化错误,我知道为什么但我错过了什么?
更新:我发现了我的错误,但似乎 ControlBase 中的 if (this.SaveEvent!= null) 始终为 null
家长控制代码:
public partial class myControl : ControlBase
{
private myChildControl __myChildControl;
private void myControl_PreRender(object sender, EventArgs e)
{
// error occurs here
//this.__myChildControl.SaveEvent += new myChildControl.SaveEventHandler(__myChildControl_SaveEvent);
// found my error
this.SaveEvent += new myChildControl.SaveEventHandler(__myChildControl_SaveEvent);
}
private void __myChildControl _SaveEvent(object sender, CustomEventArgs e)
{
this.Label1.Text = e.CustomEventArg1.ToString();
this.Label2.Text = e.CustomEventArg2.ToString();
}
}
在 RadWindow 中启动子控件:
public partial class myChildControl : ControlBase
{
protected void btnSave_OnClick(object sender, EventArgs e)
{
CustomEventArgs _cea = new CustomEventArgs {CustomEventArg1 = 123, CustomEventArg2 = 12};
callBaseMethod(_cea);
}
}
控制基代码:
public class ControlBase : UserControl
{
public event CustomEventHandler SaveEvent;
public delegate void CustomEventHandler(object sender, CustomEventArgs e);
internal void callBaseMethod(CustomEventArgs cea)
{
if (this.SaveEvent!= null)
{
this.SaveEvent(this, cea);
}
}
}
CustomEventArgs 类:
public class CustomEventArgs : EventArgs
{
public int CustomEventArgs1 { get; set; }
public int CustomEventArgs2 { get; set; }
}
【问题讨论】:
标签: c# asp.net user-controls delegates event-handling