Mail Composer无法从UIPreviewAction启动

Question

在我的Peek视图的视图控制器中我有一个应用程序:

- (NSArray*)previewActionItems {  

    /  
    UIPreviewAction *action1 = [UIPreviewAction actionWithTitle:@"Post to Facebook" style:UIPreviewActionStyleDefault handler:^(UIPreviewAction * _Nonnull action, UIViewController * _Nonnull previewViewController) {  


    }];  

    UIPreviewAction *action2 = [UIPreviewAction actionWithTitle:@"Message" style:UIPreviewActionStyleDefault handler:^(UIPreviewAction * _Nonnull action, UIViewController * _Nonnull previewViewController) {  


    }];  

    UIPreviewAction *action3 = [UIPreviewAction actionWithTitle:@"Email" style:UIPreviewActionStyleDefault handler:^(UIPreviewAction * _Nonnull action, UIViewController * _Nonnull previewViewController) {  
        [self displayComposerSheet];  


    }];  

    /  
    NSArray *actions = @[action1, action2, action3];  

    /  
    return actions;  
} 

这成功地允许我在3D Touch之后拉出一张预览动作.displayComposerSheet是:

-(void)displayComposerSheet  
{  
    NSLog(@"Mail Button Pressed");
    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];  
    picker.mailComposeDelegate = self;  

    [picker setSubject:@"Check out this article from Fritch"];  


    /  
    NSArray *toRecipients = [NSArray arrayWithObject:@"friend@example.com"];  

    [picker setToRecipients:toRecipients];  

    /  
    NSString *emailBody = self.finalObject.articleImage;  
    [picker setMessageBody:emailBody isHTML:YES];  

    [self presentViewController:picker animated:YES completion:nil];  
    [picker release];  
} 

但是,邮件编写器永远不会出现.请帮忙.

Answer 1

问题可能是在显示Peek视图时视图层次结构不正常.

尝试使用根视图控制器来呈现选择器:

[[UIApplication sharedApplication].delegate.window.rootViewController presentViewController:picker animated:YES completion:nil];