iOS textField输入数字时每隔3个数字就用逗号隔开

有些项目的要求比较高，类似于输入银行卡号、电话号码、金额时，为了提高用户体验。输入这些类型的数字一般客户要求添加格式。这对于开发人员来说无疑是增加难度。在此提供一种输入金额时每隔三个数字就用逗号隔开的方法供大家参考，如有不足之处请指教。

- (void)viewDidLoad {

    [super
viewDidLoad];

    [self.outstandingTextField
addTarget:self
action:@selector(textFieldDidChange:)
forControlEvents:UIControlEventEditingChanged];//给textField 添加监听事件

    

}

-(void)textFieldDidChange :(UITextField *)theTextField{
    theTextField.attributedText = [self setBalance:theTextField.text];

}

-(NSMutableAttributedString *)setBalance:(NSString *)balance{
   
if (balance == nil) {
        balance =
@"0";
    }

    NSString *newBalance = [balance
stringByReplacingOccurrencesOfString:@","
withString:@""];

    NSNumberFormatter *formatter = [NSNumberFormatter
new];

    [formatter setNumberStyle:NSNumberFormatterDecimalStyle]; 

    
   
NSString *formattedBalance = [formatter
stringFromNumber:[NSNumber
numberWithInteger:[newBalance integerValue]]];

    

    NSMutableAttributedString *vAttrString = [[NSMutableAttributedString
alloc]initWithString:[NSString
stringWithFormat:@" %@", formattedBalance]
attributes:nil];

    
   
NSLog(@"===---- %@",vAttrString);
   
return vAttrString;