UIImagePickerController 中的覆盖图像取决于设备方向答案

【问题标题】：Overlay image in UIImagePickerController depending on device orientationUIImagePickerController 中的覆盖图像取决于设备方向
【发布时间】：2011-07-26 18:07:11
【问题描述】：

我有两个叠加图像，我想根据设备方向在相机视图中显示 - 一个用于水平方向，一个用于垂直方向（overlay_v.png 和 overlay_h.png）。当设备从纵向旋转到垂直方向时，叠加图像也应该改变。

使用 beginGeneratingDeviceOrientationNotifications 我只能确定设备方向，但无法更改叠加图像。任何帮助/不同的方法将不胜感激。

- (IBAction) getPhoto:(id) sender {
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;

    if((UIButton *) sender == choosePhotoBtn) {
        sourceCamera = false;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    } else {
        sourceCamera = true;
        picker.sourceType = UIImagePickerControllerSourceTypeCamera;

        //overlay image (cannot dynamically switch from vertical to horizontal in here)
        UIImageView *anImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"overlay_v.png"]];            
        anImageView.frame = CGRectMake(0, 0, anImageView.image.size.width, anImageView.image.size.height);
        picker.cameraOverlayView = anImageView;

        //device orientation check   
        [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didOrientation:) name:@"UIDeviceOrientationDidChangeNotification" object:nil];

        [anImageView release];        
    }
    [self presentModalViewController:picker animated:YES];

}

- (void) didOrientation: (id)object {
    UIInterfaceOrientation interfaceOrientation = [[object object] orientation];

    if (interfaceOrientation == UIInterfaceOrientationPortrait || interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
        NSLog(@"portrait");
    } else if (interfaceOrientation == UIInterfaceOrientationLandscapeRight || interfaceOrientation == UIInterfaceOrientationLandscapeLeft ){
        NSLog(@"landscape");
    }

}

【问题讨论】：

您想知道在 didOrientation 方法中如何将第一个图像视图更改为第二个图像视图？

标签： iphone orientation overlay uiimagepickercontroller

【解决方案1】：

选择器显示后，您将无法更改cameraOverlayView 属性。但是，您可以修改视图本身。创建一个名为 overlayView 的 UIView 属性。将两个图像作为子视图添加到此视图中，并使用每个图像上的 tag 属性轻松再次获取该视图。隐藏当前方向不应该显示的那个。

- (void) didOrientation: (id)object {
   UIInterfaceOrientation interfaceOrientation = [[object object] orientation];
   UIImageView *pImageView = [self.overlayView viewWithTag:10];
   UIImageView *lImageView = [self.overlayView viewWithTag:20];

   if (interfaceOrientation == UIInterfaceOrientationPortrait || 
       interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
      NSLog(@"portrait");
      pImageView.hidden = NO;
      lImageView.hidden = YES;
   } else if (interfaceOrientation == UIInterfaceOrientationLandscapeRight || 
      interfaceOrientation == UIInterfaceOrientationLandscapeLeft ){
      NSLog(@"landscape");
      pImageView.hidden = YES;
      lImageView.hidden = NO;
   }

}

【讨论】：