代码没有被调用

Question

在 shouldChnageTextInRange 的方法中，我有一段代码验证 textField 的货币输入。然后我尝试从 textField 获取 NSLog，但我从未得到结果。

这是我从 this answer:

获得的编辑代码

- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    if (textField == self.myTextField)
    {
        static NSString *numbers = @"0123456789";
        static NSString *numbersPeriod = @"01234567890.";
        static NSString *numbersComma = @"0123456789,";   

        if (range.length > 0 && [string length] == 0) {
            // enable delete
            return YES;
        }

        NSString *symbol = [[NSLocale currentLocale] objectForKey:NSLocaleDecimalSeparator];
        if (range.location == 0 && [string isEqualToString:symbol]) {
            // decimalseparator should not be first
            return NO;
        }
        NSCharacterSet *characterSet;
        NSRange separatorRange = [textField.text rangeOfString:symbol];
        if (separatorRange.location == NSNotFound) {
            if ([symbol isEqualToString:@"."]) {
                characterSet = [[NSCharacterSet characterSetWithCharactersInString:numbersPeriod] invertedSet];
            }
            else {
                characterSet = [[NSCharacterSet characterSetWithCharactersInString:numbersComma] invertedSet];              
            }
        }
        else {
            // allow 2 characters after the decimal separator
            if (range.location > (separatorRange.location + 2)) {
                return NO;
            }
            characterSet = [[NSCharacterSet characterSetWithCharactersInString:numbers] invertedSet];               
        }
        return ([[string stringByTrimmingCharactersInSet:characterSet] length] > 0);
    }
    NSLog(@"%@", textField.text);
}

最后一个 NSLog 永远不会被调用。我该怎么做才能解决这个问题？（我将 delegate 设置为 self。）

Answer 1

你应该把代码放在return之前。

- (BOOL) textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    NSLog(@"%@", textField.text); //before return
    ...
}

Answer 2

once方法return它不执行下一行代码。在你的代码中一些小错误更正代码 NSLog(@"%@", textField.text);应该在代码 return ([[string stringByTrimmingCharactersInSet:characterSet] length] > 0);

之前

代码没有被调用

Code is not getting called

objective-c

uitextfield

ios

uitextfielddelegate