iphone - 将文本字段输入限制为 1 并在文本字段上隐藏光标

Question

在我的应用程序中，我有一个使用 4 个文本字段输入 4 位密码的视图。当用户触摸第一个文本字段并输入第一个字符时，控件应自动转到第二个字符，依此类推.. 第四次验证应该发生。用户也应该当他触摸文本框时看不到光标。如何做到这一点？

Answer 1

尝试以下：

   - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    if( [textField.text length]==0)
    {
        [nextText becomeFirstResponder];
    }

    return YES;
}

Answer 2

尝试这个

     - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:      (NSRange)range     replacementString:(NSString *)string
    { 

    if(theTextField == wordTextField1) {
    [wordTextField1 setText:string];
     if(string.length == 1) {
     [wordTextField2 becomeFirstResponder];
    }
     }
    else if(theTextField == wordTextField2) {
    [wordTextField2 setText:string];
    if(string.length == 1) {
    [wordTextField3 becomeFirstResponder];
     }
       }
         else if(theTextField == wordTextField3) {
       [wordTextField3 setText:string];
    if(string.length == 1) {
    [wordTextField4 becomeFirstResponder];
    }
    }
      else if(theTextField == wordTextField4) {
      [wordTextField4 setText:string];
      if(string.length == 1) {
      [wordTextField1 becomeFirstResponder];
     }
     }
    }