objective-c - 如何在按下时传递uibutton的标签

Question

我想在按下 uibutton 时将它的标签传递给指定的方法，但是当我尝试这个时，我收到一条错误消息。请帮忙。代码：

   UIButton *deleteButton  = [[UIButton alloc]initWithFrame:CGRectMake(230, dateLabel.frame.origin.y, 70, 27)];
    [deleteButton addTarget:self action:@selector(deleteButtonPressed:i) forControlEvents:UIControlEventTouchDown];
    [deleteButton setBackgroundImage:[UIImage imageNamed:@"delete.jpg"] forState:UIControlStateNormal];
    [deleteButton setTag:i];

进而

    -(void)deleteButtonPressed:(int)tag
{
    NSLog(@"Button Pressed");
    NSLog(@"%i", tag);


}

Answer 1

事件处理程序本身不传递标签，它们传递整个按钮：

UIButton *deleteButton  = [[UIButton alloc]initWithFrame:CGRectMake(230, dateLabel.frame.origin.y, 70, 27)];
[deleteButton addTarget:self action:@selector(deleteButtonPressed:) forControlEvents:UIControlEventTouchDown];
[deleteButton setBackgroundImage:[UIImage imageNamed:@"delete.jpg"] forState:UIControlStateNormal];
[deleteButton setTag:i];

现在您可以从传入的按钮中获取标签，如下所示：

-(void)deleteButtonPressed:(UIButton*)button {
    NSLog(@"Button Pressed, tag=%i", button.tag);
}

Answer 2

您不能在 @selector 中传递参数。那应该只是@selector(deleteButtonPressed:)。

然后在action方法中：

    -(void)deleteButtonPressed:(UIButton *) sender
{
    NSLog(@"Button Pressed");
    NSLog(@"%d", sender.tag);


}