iOS UITextfield input int

需求 ：iOS UITextfield 只允许输入数字 粘贴板如果有除数字之外的字符全部过滤掉，只允许数字上屏显示

1. 设置键盘样式 keyboardtype = UIKeyboardTypeASCIICapableNumberPad;
2. • (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
     if ([self validateIncludeInt:string]) {
     NSScanner *scanner = [NSScanner scannerWithString:string];
     [scanner scanUpToCharactersFromSet:[NSCharacterSet decimalDigitCharacterSet] intoString:nil];
     int number;
     [scanner scanInt:&number];
     NSString *stringNumber = [NSString stringWithFormat:@"%d",number];
     [textField replaceRange:textField.selectedTextRange withText:stringNumber];
     }
     return [string isEqualToString:@""];
     }

• (BOOL)validateIncludeInt:(NSString *)stringInput {
  NSScanner *scanner = [NSScanner scannerWithString:stringInput];
  [scanner scanUpToCharactersFromSet:[NSCharacterSet decimalDigitCharacterSet] intoString:nil];
  int number;
  return [scanner scanInt:&number];
  }
• (BOOL)validateOnlyChinese:(NSString *)stringInput {
  BOOL result = NO;
  NSString *match = @"(^[\u4e00-\u9fa5]+$)";
  NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF matches %@",match];
  result = [predicate evaluateWithObject:stringInput];
  return result;
  }
• (BOOL)validateIncludeChinese:(NSString *)stringInput {
  BOOL result = NO;
  for(int i=0; i< [stringInput length];i++) {
  int a = [stringInput characterAtIndex:i];
  if( a > 0x4e00 && a < 0x9fff){
  result = YES;
  }
  }
  return result;
  }