iOS 7 -(无效)setupAlertCtr :(NSString*)choseMenuType compatibility

Question

-(void)setupAlertCtr:(NSString*)choseMenuType
    {
        self.alertContForNew = [UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:UIAlertControllerStyleActionSheet];

        UIAlertAction *cancel = [UIAlertAction actionWithTitle:@"İptal" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action)
                                 {

                                 }];

       [self.alertContForNew addAction:cancel];
    }

此代码适用于 iOS 8，但当我尝试在 iOS 7 上使用时出现崩溃问题是什么？

Answer 1

因为 UIAlertController只支持iOS 8及以后的版本，在iOS 7中我们还是要用UIActionSheet或 UIAlertView

所以你必须像下面这样放置条件

if (ios8)// change your condition which check ios8 or later.
{
    UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"Title" message:nil preferredStyle:UIAlertControllerStyleActionSheet];
    UIAlertAction* cancelAction = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel  handler:^(UIAlertAction * action)
                                    {
                                        [alert dismissViewControllerAnimated:YES completion:nil];
                                    }];

    UIAlertAction* alertAction1 = [UIAlertAction actionWithTitle:@"Your title" style:UIAlertActionStyleDefault  handler:^(UIAlertAction * action)
                                   {
                                      //do what you want
                                   }];

    [alert addAction:cancelAction];
    [alert addAction:alertAction1];

    [self presentViewController:alert animated:YES completion:nil];
}
else
{
    UIActionSheet *actionSheet = [[UIActionSheet alloc]initWithTitle:@"Title" delegate:self cancelButtonTitle:@"Cancel" destructiveButtonTitle:nil otherButtonTitles:@"Your Title",nil];
    [actionSheet showInView:self.view];
}

对于 iOS 7 你必须实现 <UIActionSheetDelegate>及其方法

-(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
    switch (buttonIndex) {
    case 0:
          //do what you want.
        break;
    case 1:
        break;
    default:
        break;
    }
}