Objective-c UITapGestureRecognizer 无法识别的选择器答案

【问题标题】：Objective-c UITapGestureRecognizer unrecognized selectorObjective-c UITapGestureRecognizer 无法识别的选择器
【发布时间】：2017-03-07 12:22:44
【问题描述】：

我有一个包含 UILabel 的单元格的 UITableView。当我点击 UILabel 时，我想执行一个动作，因此我添加了一个 UITapGestureRecognizer。

UILabel *telephone = (UILabel *)[cell.contentView viewWithTag:420];
telephone.userInteractionEnabled = YES;
UITapGestureRecognizer *tapToCall = [[UITapGestureRecognizer alloc] initWithTarget:telephone action:@selector(tapToCall:)];
[telephone addGestureRecognizer:tapToCall];

然后我定义了选择器方法：

-(void)tapToCall: (UITapGestureRecognizer*) sender {
    UILabel *telephone = (UILabel *) sender.view;
    NSLog(@"%@", telephone.text);
}

但现在我在触摸 UILabel 时收到错误消息：

2017-03-07 13:17:49.220 [37354:2794848] -[UILabel tapToCall:]: unrecognized selector sent to instance 0x7fc39f459250

2017-03-07 13:17:49.253 [37354:2794848] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UILabel tapToCall:]: unrecognized selector sent to instance 0x7fc39f459250'

我在这里做错了什么？

【问题讨论】：

标签： ios objective-c uitableview uilabel uitapgesturerecognizer

【解决方案1】：

从initWithTarget:telephone 更改目标（不适用于特定控件）

UITapGestureRecognizer *tapToCall = [[UITapGestureRecognizer alloc] initWithTarget:telephone

到initWithTarget:self（需要在当前类中调用）

UITapGestureRecognizer *tapToCall = [[UITapGestureRecognizer alloc] initWithTarget:self

完整答案

UILabel *telephone = (UILabel *)[cell.contentView viewWithTag:420];
UITapGestureRecognizer *tapToCall = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapToCall:)];
telephone.userInteractionEnabled = YES;
[telephone addGestureRecognizer:tapToCall];

【讨论】：

【解决方案2】：

这样改

UITapGestureRecognizer *tapToCall = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapToCall:)];
[telephone addGestureRecognizer:tapToCall];

【讨论】：

【解决方案3】：

应该是这样的

UILabel *telephone = (UILabel *)[cell.contentView viewWithTag:420];

UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer   alloc] initWithTarget:self action:@selector(handleTap:)];

[tapRecognizer setDelegate:self];
[tapRecognizer setNumberOfTapsRequired:1];

[telephone addGestureRecognizer:tapRecognizer];

 - (void)handleTap: (UITapGestureRecognizer*) sender {

    UILabel *telephone = (UILabel *) sender.view;

    NSLog(@"%@", telephone.text);
    NSLog(@"%ld", (long)telephone.tag);

     switch(telephone.tag) {
        case 0: { }
            break;
        case 1: { }
            break;
    }
}

【讨论】：