UIAlertController: textfield not returning string

问题

There is something unexpected I cannot sort out. I have an alertController with textfields. I try to get the string value of one of them. Everything works fine when the string length is less than 11 characters. Above this threshold, the string is null.

Could anyone give me a hint on what there is going on?

Just in case, I put my code below:

[alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.placeholder = @"Name";
        textField.textColor = [UIColor blueColor];
        textField.clearButtonMode = UITextFieldViewModeWhileEditing;
        textField.borderStyle = UITextBorderStyleRoundedRect;
    }];

[alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        NSArray *textfields = alertController.textFields;
        UITextField *nameTextfield = textfields[0];
        self.textFieldString = nameTextfield.text;

        NSLog(@"self.textFieldString is: %@", self.textFieldString); // -> this returns a null value when the string length is > 11


    }]];

Thanks!

回答1:

are you sure ^(UITextField *textField) and nameTextfield is equal to both, make sure you get the current textfield.

[alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
    **NSLog(@"%s", textField);**
    textField.placeholder = @"Name";
    textField.textColor = [UIColor blueColor];
    textField.clearButtonMode = UITextFieldViewModeWhileEditing;
    textField.borderStyle = UITextBorderStyleRoundedRect;
}];

[alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
    NSArray *textfields = alertController.textFields;
    UITextField *nameTextfield = textfields[0];
    **NSLog(@"%s", nameTextfield);**
    self.textFieldString = nameTextfield.text;

    NSLog(@"self.textFieldString is: %@", self.textFieldString); // -> this returns a null value when the string length is > 11


}]];

i changed your code , run it ,make sure the address same to each other.

回答2:

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];

[alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
    textField.placeholder = @"Name";
    textField.textColor = [UIColor blueColor];
    textField.clearButtonMode = UITextFieldViewModeWhileEditing;
    textField.borderStyle = UITextBorderStyleRoundedRect;
}];

[alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
    NSArray *textfields = alertController.textFields;
    UITextField *nameTextfield = textfields[0];
    //        self.textFieldString = ;

    NSLog(@"self.textFieldString is: %@", nameTextfield.text); // -> this returns a null value when the string length is > 11


}]];
[self presentViewController:alertController animated:YES completion:nil];

Note :- If You add more textfields then NSArray *textfields contains more textfields. So you can use tag for identify textfields.

来源：https://stackoverflow.com/questions/41514696/uialertcontroller-textfield-not-returning-string

标签

objective-c

string

uitextfield

uialertcontroller