Need to display a camera preview inside a circular view

问题

I need to implement a circular camera preview. I am using camera2 api with TextureView. I added the layout as follows:

 <FrameLayout>
 <TextureView/>
 <CircularImageView/>
 <FrameLayout/>

Doing this I am getting the below result: As you can see, the camera preview is displayed in a square, but I want that to be a circular one, also keeping the yellow image in the background. How can I achieve this ? I did refer few examples on similar questions perviously asked but they are done using old camera api and not TextureView.

Any help is appreciated.

回答1:

Instead of CircularImageView, you need a regular image view, where you load a png with circular transparent hole of desired size.

So, the proposed hierarchy could be something like this:

<FrameLayout size="match_parent">
   <TextureView size=<calculated_to_match_camera> centered />
   <ImageView size="match_parent" src="full-screen-gradient-with-transparent-circle-in-center.png" />
<FrameLayout />

The shorthand above assumes size --> android:width and android:height. The texture size is set programmatically to fit the camera preview aspect ratio, and have the region of interest exposed through the circular hole in the ImageView layer above it.

来源：https://stackoverflow.com/questions/47239178/need-to-display-a-camera-preview-inside-a-circular-view