判断输入钱的正则表达式，可输入正负，小数点前5位，小数点后2位，位数可控
UItextField 代理方法
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
NSString *toString = [textField.text stringByReplacingCharactersInRange:range withString:string];
if (toString.length > 0) {
NSString *stringRegex = @"(\\+|\\-)?(([0]|(0[.]\\d{0,2}))|([1-9]\\d{0,4}(([.]\\d{0,2})?)))?";
NSPredicate *phoneTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", stringRegex];
BOOL flag = [phoneTest evaluateWithObject:toString];
if (!flag) {
return NO;
}
}
return YES;
}
