alertController.m

changeAlert = [UIAlertController alertControllerWithTitle:@"title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];
UIAlertController* __weak weakAlert = changeAlert;

UIAlertAction *alertActionOk = [UIAlertAction actionWithTitle:@"Ok" style:UIAlertActionStyleDestructive handler:^(UIAlertAction *action) {
    UITextField *t = [[weakAlert textFields] firstObject];
    DLog(@"%@",t.text);
    [weakAlert dismissViewControllerAnimated:YES completion:nil];
}];
UIAlertAction *alertActionCancel = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
    DLog(@"%@",action);
}];
UIAlertAction *alertActionTest = [UIAlertAction actionWithTitle:@"Test" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
    UITextField *t = [[weakAlert textFields] firstObject];
    DLog(@"%@",t.text);
    [weakAlert dismissViewControllerAnimated:YES completion:nil];
}];

[weakAlert addAction:alertActionOk];
[weakAlert addAction:alertActionCancel];
[weakAlert addAction:alertActionTest];

[weakAlert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
    textField.placeholder = @"pls";
}];

[self.viewController presentViewController:weakAlert animated:YES completion:nil]