UITextField限制输入两位小数

• (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
  // 限制只能输入数字
  BOOL isHaveDian = YES;
  if ([string isEqualToString:@" "]) {
  return NO;
  }

  if ([textField.text rangeOfString:@"."].location == NSNotFound) {
  isHaveDian = NO;
  }
  if ([string length] > 0) {

    unichar single = [string characterAtIndex:0];//当前输入的字符
    if ((single >= '0' && single <= '9') || single == '.') {//数据格式正确
        
        if([textField.text length] == 0){
            if(single == '.') {
                
                [textField.text stringByReplacingCharactersInRange:range withString:@""];
                return NO;
            }
        }
        
        //输入的字符是否是小数点
        if (single == '.') {
            if(!isHaveDian)//text中还没有小数点
            {
                isHaveDian = YES;
                return YES;
                
            }else{
                
                [textField.text stringByReplacingCharactersInRange:range withString:@""];
                return NO;
            }
        }else{
            if (isHaveDian) {//存在小数点
                
                //判断小数点的位数
                NSRange ran = [textField.text rangeOfString:@"."];
                if (range.location - ran.location <= 2) {
                    return YES;
                }else{
                    
                    return NO;
                }
            }else{
                return YES;
            }
        }
    }else{//输入的数据格式不正确
        
        [textField.text stringByReplacingCharactersInRange:range withString:@""];
        return NO;
    }
  

  }
  else
  {
  return YES;
  }
  }