Question

我在View Controller的viewDidLoad方法实现中设置了文本消息窗口。如果特定的NSString对象包含“YES”，那么我会调用我的文本消息窗口的方法并弹出它。

所有这一切都运行正常，唯一的问题是我的文本消息方法调用实际上是我的viewDidLoad中的第一件事，但由于某种原因，在执行viewDidLoad中的所有其他内容后弹出文本消息窗口。

在我的viewDidLoad中，在短信窗口代码下方，我设置并启动AVCapture会话，并创建一个“预览图层”，显示相机看到的内容。

即使此代码低于文本消息窗口代码，您也可以在弹出文本消息窗口之前看到相机的预览图层几秒钟。

这是我的viewDidLoad方法实现。请注意[self showSMS]的文本消息窗口方法调用在其他所有内容之前是先行的：

- (void)viewDidLoad
{

    [super viewDidLoad];

    if([_justFinishedSigningUp isEqual:@"YES"]) {

        [self showSMS];        
    }



    if ([self respondsToSelector:@selector(setNeedsStatusBarAppearanceUpdate)]) {
        // iOS 7
        [self prefersStatusBarHidden];
        [self performSelector:@selector(setNeedsStatusBarAppearanceUpdate)];
    } else {
        // iOS 6
        [[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationSlide];
    }


    _session =[[AVCaptureSession alloc]init];


    [_session setSessionPreset:AVCaptureSessionPresetPhoto];


    _inputDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];


    NSError *error;


    _deviceInput = [AVCaptureDeviceInput deviceInputWithDevice:_inputDevice error:&error];


    if([_session canAddInput:_deviceInput])
        [_session addInput:_deviceInput];


    _previewLayer = [[AVCaptureVideoPreviewLayer alloc]initWithSession:_session];


    CALayer *rootLayer = [[self view]layer];

    [rootLayer setMasksToBounds:YES];


    [_previewLayer setFrame:CGRectMake(0, 0, rootLayer.bounds.size.width, rootLayer.bounds.size.height/2)];

    [_previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];


    [rootLayer insertSublayer:_previewLayer atIndex:0];


    _stillImageOutput = [[AVCaptureStillImageOutput alloc] init];


    [_session addOutput:_stillImageOutput];

    [_session startRunning];

    }

然后是帮助控制文本消息窗口的方法实现：

- (void)showSMS {

    if(![MFMessageComposeViewController canSendText]) {
        UIAlertView *warningAlert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Your device doesn't support SMS!" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [warningAlert show];
        return;
    }

    NSArray *recipents = _usersToInviteToApp;
    NSString *message = _textMessageInviteText;

    MFMessageComposeViewController *messageController = [[MFMessageComposeViewController alloc] init];
    messageController.messageComposeDelegate = self;
    [messageController setSubject:@"New Message"];
    [messageController setRecipients:recipents];
    [messageController setBody:message];

    // Present message view controller on screen
    [self presentViewController:messageController animated:YES completion:nil];
}


- (void)messageComposeViewController:(MFMessageComposeViewController *)controller didFinishWithResult:(MessageComposeResult) result
{
    switch (result) {
        case MessageComposeResultCancelled:
            break;

        case MessageComposeResultFailed:
        {
            UIAlertView *warningAlert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Failed to send SMS!" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
            [warningAlert show];
            break;
        }

        case MessageComposeResultSent:
            break;

        default:
            break;
    }

    [self dismissViewControllerAnimated:YES completion:nil];
}

Answer 1

您正在使用animated:YES中的viewDidLoad向视图中加载某些内容，该内容会在屏幕上显示任何内容之前发生（[self presentViewController:messageController animated:YES completion:nil];）

您是否尝试将所有内容移至viewDidAppear，或者如果您希望屏幕显示在所有内容之前，请尝试在animated:NO方法中设置-(void)showSMS。

viewDidLoad中的文本消息窗口在其他所有内容后弹出

1 个答案: