dismissViewControllerAnimated not being called on iPhone

Question

I have the following code where I am trying to show a PDF preview. It words perfectly on an iPad however when I am trying to do it on a iPhone it dosnt work.

QLPreviewController* preview = [[QLPreviewController alloc] init];
        preview.dataSource = self;
        [self dismissViewControllerAnimated:YES completion:^{
            [self presentViewController:preview animated:YES completion:nil];
        }];

The thread on the iPhone never makes it to this line

[self presentViewController:preview animated:YES completion:nil];

but works fine on ipad.. I am not sure what to even look at. Any help would be appreaciated.

Answer 1

要访问块内的实例/变量（在块外声明），您需要像这样声明这些实例/变量：__block类型标识符=初始值（可选），例如，在您的情况下，使用__block QLPreviewController * Preview = [[QLPreviewController alloc] init];

Answer 2

Try to use

[self.presentingViewController presentViewController:preview animated:YES completion:nil];

instead of

[self presentViewController:preview animated:YES completion:nil];