自定义叠加层不透明

Question

我做的很简单。我用一个分段控件创建了一个简单的NIB。主要用于测试目的。我正在尝试使用此NIB加载到UIImagePickerController叠加层。但加载后，叠加层不透明。只需在摄像机视图顶部的中央显示白色背景和按钮即可。我试过overlay.opaque = NO没有运气。

这是我的代码：

@property (nonatomic) IBOutlet UIView *viewTest;
@property (nonatomic, weak) IBOutlet UISegmentedControl *switchButtonTest;

后来，我有这个方法（主要来自Apple的APLViewController示例）

- (void)showImagePickerForSourceType:(UIImagePickerControllerSourceType)sourceType
{
    UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
    imagePickerController.modalPresentationStyle = UIModalPresentationCurrentContext;
    imagePickerController.sourceType = sourceType;
    imagePickerController.delegate = self;

    if (sourceType == UIImagePickerControllerSourceTypeCamera)
    {
        imagePickerController.showsCameraControls = NO;

        [[NSBundle mainBundle] loadNibNamed:@"ViewTest" owner:self options:nil];
        self.viewTest.frame = imagePickerController.cameraOverlayView.frame;
        imagePickerController.cameraOverlayView = self.viewTest;
        self.viewTest = nil;
    }

    self.imagePickerController = imagePickerController;
    [self presentViewController:self.imagePickerController animated:YES completion:nil];
}

Answer 1

要摆脱白色背景视图，请将其颜色更改为clearColor（或者首先不要使用它）。为了使分段控件更不透明，将其alpha设置为0.2。

Answer 2

在self.viewTest背景中填充清晰的颜色。