如何讓uitextview僅接受退格鍵和刪除鍵

Question

我希望UItextView在TextView.contentSize.height增長超出特定限制後不再接受任何字符。但可以刪除內容。如何實現這一點。任何建議？

Answer 1

使用textfield和textview的委託和數據源。

例如文本字段委託方法

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{ if (textField == self.txtContact) { 
      if ([DebugLog isEqualToString:@"1"]) { 
       NSLog(@"%@",textField.text); 
      } 
      char *x = (char*)[string UTF8String]; 
      if([string isEqualToString:@"-"] || [string isEqualToString:@"("] || [string isEqualToString:@")"] || [string isEqualToString:@"0"] || [string isEqualToString:@"1"] || [string isEqualToString:@"2"] || [string isEqualToString:@"3"] || [string isEqualToString:@"4"] || [string isEqualToString:@"5"] || [string isEqualToString:@"6"] || [string isEqualToString:@"7"] || [string isEqualToString:@"8"] || [string isEqualToString:@"9"] || x[0]==0 || [string isEqualToString:@" "]) { 
        if ([DebugLog isEqualToString:@"1"]) { 
         NSLog(@"%d",[string length]); 
        } 
       NSUInteger newLength = [textField.text length] + [string length]; 
       if (!CheckDigit) { 
        if ([textField.text length] == 4) { 
         textField.text =[NSString stringWithFormat:@"%@-",textField.text]; 
         CheckDigit=TRUE; 
        } 


       } 
       if (!CheckDigit1) { 
        if ([textField.text length] == 9) { 
         textField.text =[NSString stringWithFormat:@"%@-",textField.text]; 
         CheckDigit1=TRUE; 
        } 


       } 
       if ([textField.text length]<=4) { 
        CheckDigit=FALSE; 
       } 
       if ([textField.text length]<=9 && [textField.text length]>=4) { 
        CheckDigit1=FALSE; 
       } 

       return (newLength > 11) ? NO : YES; 

      } else { 
       return NO; 
      } 

} 

Answer 2

的下面有一個在所述UITextFieldDelegate協議。
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string是你的朋友。

Answer 3

用戶以下的委託方法，以避免用戶輸入任何內容

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

    return 0;/// Dont allow user to type 

return 1; ///Allow user to type 

    }