使用FirstResponder与iPhone SDK的文本验证问题

Question

我想验证我的文本字段，以便如果有问题，用户输入它会捕获它并显示警报（得到该部分），而不是去下一个领域（不能得到那部分）。任何想法，我在做什么错了？

- (BOOL)textFieldShouldReturn:(UITextField *)textField 
{ 
    if (textField == txtUserName) 
    { 
     [txtUserName2 becomeFirstResponder]; 
    } 
    else if (textField == txtUserName2) 
    { 
     [txtUserName3 becomeFirstResponder]; 
    } 
    else if (textField == txtUserName3) 
    { 
     [txtUserName4 becomeFirstResponder]; 
    } 
    else if (textField == txtUserName4) 
    { 
     [txtUserName5 becomeFirstResponder]; 
    } 
    return NO; 
} 
- (void)textFieldDidEndEditing:(UITextField *)textField 
{ 

    if (textField == txtUserName) 
    { 
     NSString *userNameOne = txtUserName.text; 
     double numOne = [userNameOne intValue]; 

      if(numOne < 40 || numOne > 100) 
      { 

       //play sound and vibrate for alert 
       NSString *bonkSoundFile = [[NSBundle mainBundle] pathForResource:@"alertSound" ofType:@"mp3"]; 
       NSURL *fileURL = [NSURL fileURLWithPath:bonkSoundFile]; 
       SystemSoundID bonkSoundID; 
       AudioServicesCreateSystemSoundID((CFURLRef) fileURL, &bonkSoundID); 
       AudioServicesPlaySystemSound(bonkSoundID); 
       AudioServicesPlaySystemSound (kSystemSoundID_Vibrate); //vibrate 

       //show alert 
       UIAlertView *alert = [[UIAlertView alloc] 
           initWithTitle:@"Age Error" 
           message:@"Your age must be at least 40 years old and less than 100 years old" 
           delegate:nil 
           cancelButtonTitle:@"OK" 
           otherButtonTitles:nil]; 
       [alert show]; 
       [alert release]; 

//if there is an error, then don't go to next field but make current textField the //FirstResponder 
       [txtUserName becomeFirstResponder]; 
      } 
     } 

等共五个字段。我只是不知道我做错了什么......

Answer 1

您是否尝试过把验证代码为

- (BOOL)textFieldShouldEndEditing:(UITextField *)textField 

，并让它不归路，当你不希望继续到下一个领域？