在C#中,sender通常是一个object类型,表示事件的发送者。如果要将sender转换为具体类型,可以使用类型转换或者as关键字进行转换。例如: Button button = sender as Button; if (button != null) { // sender是一个Button类型 } 复制代码 或者: if (sender is Button) { Button button = (Button)sender; // ...
值得注意的是, Sender is (Class Name) 的 Class Name 判断是会牵涉到父阶的继承关系的, 例如: Button1 是Button,Button2是 TBitBtn, 这样的话:Button1 is TButton 为真, Button2 is TButton 也是真, 因为TBitBtn 继承自TButton, 也就是说, 球是球, 篮球也是球. 应用这个观念, 下列的程式: if Active...
sender as就是事件发起者，e存储事件发起者的一些参数 例如：private void button1_Click(object sender, System.EventArgs e){} 这里sender就是 button1，e存储 button1的一些参数。
public void OnDataBinding(object sender, EventArgs e){ Control c = null;if(sender is TextBox) c = sender as TextBox;if(sender is LinkButton) c = sender as LinkButton;}
Procedure TForm1.Button1Click(Sender:TObject);beginifSender=Button1then//事件ifSender=Button2then//事件end; 2.3 使用保留字IS来 使用 Sender procedureTForm1 xxx(Sender:TObject);beginif(senderisTedit)thenshowmessage(′thisisa editbox′);if(senderisTMemo)thenshowmessage(′thisismemo′);end; ...
指的是发送者 Sender是一个TObject类型的参数，它告诉Delphi哪个控件接收这个事件并调用相应的处理过程。你可以编写一个单一的事件处理句柄，通过Sender参数和IF…THEN…语句或者CASE语句配合，来处理多个构件。发生事件的构件或控件的值已经赋给了Sender参数，该参数的用途之一就在于：可以使用保留字IS来测试...
if Sender is TButton then showmessage((Sender as TButton).Caption) else showmessage( '没有Sender ') end; 如果你这样调用 Procedure TForm1.button2.click(sender:Tobject); begin Button1Click(nil); end; 则返回 '没有Sender ' 而如果你这样调用 ...
and further the first layer is consisted of a resin film fusing the inner-most layer of the bag body, the second layer consists of a biaxially oriented film, the third layer consists of a resin film fusing the snapping portion, and the snapping portion consists of synthetic resin having MI...
The following code example demonstrates how to use this method. This example is part of a larger example available inHow to: Implement Communication Between Local Silverlight-Based Applications. VB ImportsSystemImportsSystem.WindowsImportsSystem.Windows.ControlsImportsSystem.Windows.MessagingPartialPublicClass...
-(void)onCustomLeftButtonClick:(id)sender { if ([sender isKindOfClass:[NSNotification class]]) { NSString *showType = [sender object]; if ([@"show_left" isEqualToString:showType]) { _slider_btn_flag = 101; return; }else if ([@"show_center" isEqualToString:showType]){ ...