Question

我有一个用于创建计时器的标签。我也有2个按钮位于它下面，启动和停止是最常用的。当我按下开始按钮时，我会看到一个警报，并且警报中有一个文本字段。一切正常，但是当我在警报“开始计时器”中单击我的按钮时，我希望标签在我的文本字段中设置的数字作为计时器，并倒计时。有谁可以帮助我。我搜索了谷歌，甚至尝试过多次使用label.text = [textField.text intValue]和所有那些东西。提前致谢

- (NSString*)getTimeStr : (int) time {
seconds = time % 60;
minutes = time / 60;
return [NSString stringWithFormat:@"%02d:%02d", minutes, seconds];
}

- (IBAction)startTimer{
    // having the user enter a number in seconds
UIAlertView *inputAlert = [[UIAlertView alloc] 
                       initWithTitle:@"Enter The Time:"
               message:@"Enter your time in seconds\n"
                   delegate:self
                   cancelButtonTitle:@"Cancel"
                   otherButtonTitles:@"Start Timer", nil];

UITextField *inputField = [[UITextField alloc] initWithFrame:CGRectMake(12.0, 45.0, 260.0, 25.0)];
inputField.backgroundColor = [UIColor whiteColor];
[inputAlert addSubview:inputField];
[inputAlert setTag:1];
[inputAlert show];

NSInteger buttonIndex;

if([inputAlert tag] == 1) {
    if(buttonIndex == 1) {
        clicked = TRUE;
        mainTimer = [NSTimer scheduledTimerWithTimeInterval:1 
                                                     target:self 
                                                   selector:@selector(startTimer) 
                                                   userInfo:nil 
                                                    repeats:YES];
    }
    if(buttonIndex == 0) {
        clicked = FALSE;
        [inputAlert dismissWithClickedButtonIndex:0 animated:YES];
    }
} 

//NSString *intFromTextField = [inputField text];
//int time = [intFromTextField intValue];
timeLabel.text = [self getTimeStr:(int)inputField.text];
[timeLabel setFont:[UIFont fontWithName:@"Courier New" size:140]];

}

Answer 1

好的，这里有两件大事：

首先，您应该将alertViewStyle属性设置为UIAlertViewStylePlainTextInput，而不是将自己的文本字段添加到警报视图。

第二件事是你没有正确地将你的字符串转换为整数。嗯，你是，但是，由于某种原因，它被注释掉了。你不能只是施展它。如果你这样做，你将得到对象的内存地址，而不是值。您需要在字符串上调用integerValue。

因此，您将使用以下内容，使用UIAlertViewDelegate回调并通过textFieldAtIndex:方法访问文本字段：

- (void) alertView:(UIAlertView *) alertView clickedButtonAtIndex:(NSInteger) buttonIndex {
    // Your existing timer code. It's pretty okay as it is.

    NSUInteger enteredInteger = [[alertView textFieldAtIndex:0].text integerValue];
    myLabel.text = [self getTimeStr:enteredInteger];
}

Answer 2

首先，您不能将label.text设置为intValue，因为label.text需要NSString的实例。所以不需要添加.intValue;

您是否将UITextField添加为UIAlertView的子视图？如果是，那么尝试添加一些标记：

[youtTextField setTag:777];
[yourAlertView addSubview:yourTextField] 
// you can access yourTextField as a subview with tag = 777

如果您使用UIAlertView，则必须设置其委托： [yourAlertView setDelegate：self]; UIAlertView的委托必须符合UIAlertViewDelegate协议，因此在viewController的.h文件中添加：

@interface yourViewController : UIViewController <UIAlertViewDelegate>

为了符合该协议，您必须在ViewController中实现以下方法：

// this method is called when user taps one of AlertView's buttons
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex   
{
    // as I told, you have to have yourAlertView and timeLabel as class variables
    NSString *button=[yourAlertView buttonTitleAtIndex:buttonIndex];
    if([buttonTitle isEqualToString:@"Start Timer"]) 
    {
            NSString * timeValue = ((UITextField*)[yourAlertView viewWithTag:777]).text;
            [timeLabel setText:timeValue] // set text for your label
            [timeLabel setFont:[UIFont fontWithName:@"Courier New" size:140]];
    }
}

另外，不要忘记将timeLabel和alertView设置为类变量：

@interface yourViewController : UIViewController <UIAlertViewDelegate>
{
    UIAlertView * yourAlertView;
    UILabel * timeLabel;
}

//对startTimer的一些编辑：selector：

- (IBAction)startTimer{
// having the user enter a number in seconds
    UIAlertView *inputAlert = [[UIAlertView alloc] 
                   initWithTitle:@"Enter The Time:"
           message:@"Enter your time in seconds\n"
               delegate:self
               cancelButtonTitle:@"Cancel"
               otherButtonTitles:@"Start Timer", nil];

    UITextField *inputField = [[UITextField alloc] initWithFrame:CGRectMake(12.0, 45.0, 260.0, 25.0)];
    [inputField setTag:1];
    inputField.backgroundColor = [UIColor whiteColor];
    [inputAlert addSubview:inputField];
    [inputAlert show];
}

从UITextField中获取UITextField中的文本以设置标签的文本

2 个答案: