iOS UITextField设置金额(钱数)输入框

1.定义 

#define myDotNumbers @"0123456789.\n"

#define myNumbers @"0123456789\n"

2.UITextField

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

        NSCharacterSet *cs;

        NSUInteger nDotLoc = [textField.textrangeOfString:@"."].location;

        if (NSNotFound == nDotLoc &&0 != range.location) {

            cs = [[NSCharacterSetcharacterSetWithCharactersInString:myDotNumbers]invertedSet];

        }

        else {

            cs = [[NSCharacterSetcharacterSetWithCharactersInString:myNumbers]invertedSet];

        }

        NSString *filtered = [[stringcomponentsSeparatedByCharactersInSet:cs]
componentsJoinedByString:@""];

        BOOL basicTest = [stringisEqualToString:filtered];

        if (!basicTest) {

            returnNO;

        }

        if (NSNotFound != nDotLoc && range.location > nDotLoc +3) {

            returnNO;

        }

    returnYES;

}