Question

我有一个ScrollView，它有很多数据块。每个块都有一个UILabel。我正在for循环中创建每个块：

for(int i = 0 ; i < x ; i++){

        UILabel *claim = [[UILabel alloc]initWithFrame:CGRectMake(40,135, self.view.bounds.size.width, 30)];
        claim.text = @"claim";
        [claim setTag:i];
        NSLog(@"%ld",claim.tag);
        claim.font = [UIFont fontWithName:@"Arial" size:(20.0)];
        [claim setTextColor:[UIColor purpleColor]];

        //create a tab recogniser for claim text
        UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]
                                       initWithTarget:self
                                               action:@selector(claimClicked:)];
        [claim setUserInteractionEnabled:YES];
        [claim addGestureRecognizer:tap];
        [scrollView addSubView :claim];
}
[self.view addSubView : scrollView];

声明标签的选择器是：

- (IBAction)claimClicked:(UILabel *)sender{
    NSInteger the_tag = ((UIView*)sender).tag;
    NSLog(@"%ld",the_tag);
}

基本上我只是在点击标签时打印标签。但我得到一个例外说：

在NSlog行上

NSInvalidArgumentFormatException caused by unrecognized selector was sent to sender。

帮助。

Answer 1

实际上这里的发件人是UITapGestureRecognizer。

改为使用代码：

- (IBAction)claimClicked:(UIGestureRecognizer *)sender
{
    NSLog(@"%d",sender.view.tag);
}

Answer 2

你不能做这个定义- (IBAction)claimClicked:(UILabel *)sender。因为根据此行UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(claimClicked:)];，您的发件人为UITapGestureRecognizer.

相反试试这个..

- (IBAction)claimClicked:(UIGestureRecognizer *)sender
{
   if([sender.view isKindOfClass:[UILabel class]])
      NSLog(@"Label tag %d",sender.view.tag);
}

由无法识别的选择器导致的NSInvalidArgumentFormatException被发送到发件人：尝试打印UILabel的标签时

2 个答案: