Question

我在UI文本字段中获取电话卡号表单用户。数字的格式类似于

123-4567-890

我希望用户自动键入123 - 在4567之后插入UITextField - 依此类推。

我是使用UITextField委托方法中的以下代码完成的：

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string;
{
       NSLog(@"***** %d",textField.text.length);


             if(textField.text.length == 3) 

             {
                 textField.text  = [textField.text  stringByAppendingString:@"-"];
             }  

       return YES;
}

但问题在澄清文本时提出，当我们开始清算时。

最后3位数字890清除然后 - 添加，我们清除它并再次添加和soooo on so清除停止

我们使用

一次清除所有文字

textField.clearButtonMode = UITextFieldViewModeWhileEditing; //To clear all text at a time

但我们的要求是用户必须一次删除一个字符。

如何实现它？

Answer 1

在结算期间，replacementString应为空@""。因此，除了长度检查之外，还应检查替换字符串。像这样：

if (textField.text.length == 3 && ![string isEqualToString:@""]) {
    // append -
}

Answer 2

使用：我在这个论坛的某个地方看过这个，它对我有用

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    NSString *filter = @"###-####-###";
    if(!filter) return YES;
    NSString *changedString = [textField.text stringByReplacingCharactersInRange:range withString:string];
    if(range.length == 1 &&  string.length < range.length && [[textField.text substringWithRange:range] rangeOfCharacterFromSet:[NSCharacterSet characterSetWithCharactersInString:@"0123456789"]].location == NSNotFound)
    {
        NSInteger location = changedString.length-1;
        if(location > 0)
        {
            for(; location > 0; location--)
            {
                if(isdigit([changedString characterAtIndex:location]))
                    break;
            }
            changedString = [changedString substringToIndex:location];
        }
    }
    textField.text = filteredStringFromStringWithFilter(changedString, filter);
    return NO;
}

NSString *filteredStringFromStringWithFilter(NSString *string, NSString *filter)
{
     NSUInteger onOriginal = 0, onFilter = 0, onOutput = 0;
     char outputString[([filter length])];
     BOOL done = NO;

     while(onFilter < [filter length] && !done)
     {
         char filterChar = [filter characterAtIndex:onFilter];
         char originalChar = onOriginal >= string.length ? '\0' : [string characterAtIndex:onOriginal];
         switch (filterChar) {
         case '#':
            if(originalChar=='\0')
            {
                done = YES;
                break;
            }
            if(isdigit(originalChar))
            {
                outputString[onOutput] = originalChar;
                onOriginal++;
                onFilter++;
                onOutput++;
            }
            else
            {
                onOriginal++;
            }
            break;
        default:
            outputString[onOutput] = filterChar;
            onOutput++;
            onFilter++;
            if(originalChar == filterChar)
                onOriginal++;
            break;
        }
    }
    outputString[onOutput] = '\0';
    return [NSString stringWithUTF8String:outputString];
}

如何在UITextField Ex中每3个字符后追加一个特殊字符：（123-12346）就像' - '我做了但是在清除时发出

2 个答案: