自动检查文本字段长度并点击方法 UITextfield

Question

您好，我需要输入手机号码并验证手机文本字段范围应为 10。当文本字段值 ==10 时，我需要在 mobile textfield.text 长度变为 10 时调用一个函数。我下面的代码工作正常，但我需要再按 1 个字符（表示 11）才能调用它。请问我是怎么解决的

#define MAX_LENGTH 10

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


        if (textField.text.length >= MAX_LENGTH && range.length == 0)
        {

            if (textField.text.length==MAX_LENGTH) 
            {

                NSLog(@“Want to call Call method HERE ");

            }


            return NO; // return NO to not change text
        }


    }
     return YES;
}

Answer 1

shouldChangeCharactersInRange 在实际文本更改之前调用。如果您想在实际文本更改后执行操作，您可以尝试以下方法：

...
//start observing
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textHasChanged:) name:UITextFieldTextDidChangeNotification object:{your UITextField}];
...

- (void)textHasChanged:(NSNotification *)notification {
    UITextField *textField = [notification object];
    //check if textField.text.length >= 10
    //do stuff...
}

Answer 2

请尝试使用以下代码 -

#define MAX_LENGTH 10

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


        if (textField.text.length >= MAX_LENGTH )
        {

            if (textField.text.length==MAX_LENGTH) 
            {

                NSLog(@“Want to call Call method HERE ");

            }


            return NO; // return NO to not change text
        }


    }
     return YES;
}

Answer 3

你可以通过stringByReplacingCharactersInRange:withString:

方法获取字符改变后的字符串

#define MAX_LENGTH 10

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    if (textField == user_mobile_txtField) {
        NSString *fullString = [textField.text stringByReplacingCharactersInRange:range withString:string];

        if (fullString.length >= MAX_LENGTH && range.length == 0) {
            if (fullString.length == MAX_LENGTH) {
                NSLog(@“Want to call Call method HERE ");
            }
            return NO; // return NO to not change text
        }
    }
    return YES;
}

自动检查文本字段长度并点击方法 UITextfield

Auto check textfield length and Hit a method UITextfield

cocoa-touch

objective-c

uitextfield

ios