Is there any method to take screenshot for FrameLayout including cameraX Preview View and not to get a black screen?

[Leo Hsu]

Dear all, 

I bumped into a problem that is when I tried to get the bitmap of my FrameLayout which contains a PreviewView, I can only get the black screen for the camera region and some the overlay I put on PreviewView.

Below are my code of screenshot:
https://gist.github.com/Leo-Hsu-Design-Student/e6d92a0a39c5ed52835ce83d2833a183

I have checked the cameraX and PreviewView can work when I only call the preview.bitmap and save the screenshot image. It is as follow:

Is there any way to take a screenshot of preview and my overlay simultaneously?
Thank you in advance!

Sincerely, Leo

[Jag Saund]

Hi Leo,

When the view hierarchy is captured to a bitmap, it won't be able to capture the contents of the preview view because the preview view is backed by a texture view (or surface view depending on your configuration).
What you'll need to do is capture the two independently and merge them.

1. Create a composite bitmap which will be your final bitmap output
2. Capture the view hierarchy to a bitmap as you are right now
3. Capture the preview view to bitmap (`preview.bitmap`)
4. Merge the two in your composite bitmap:
```

val compositeBitmap = Bitmap.createBitmap(...)
val viewBitmap = ..
val previewBitmap = ..

val compositeCanvas = Canvas(compositeBitmap)

compositeCanvas.drawBitmap(previewBitmap, ...)

compositeCanvas.drawBitmap(viewBitmap, ...)

```
Be sure to recycle the bitmaps afterwards
Hope that helps!

[Leo Hsu]

Hello sir, 
Thank you for your reply first! I tried the method you suggested, and it did work!!!
Really appreciate!

```
val frameBitmap = constraintFrame.drawToBitmap()
val viewFinderBitmap = viewFinder.bitmap!!
val overlayBitmap = combine2bitmap(viewFinderBitmap, frameBitmap)
saveMediaLocally(overlayBitmap)  

```

```

private fun combine2bitmap(viewFinderBit: Bitmap, frameBit: Bitmap): Bitmap{

var bitmapOverlay: Bitmap = Bitmap.createBitmap(frameBit.width, frameBit.height, Bitmap.Config.ARGB_8888)
val canvas = Canvas(bitmapOverlay)
canvas.drawBitmap(viewFinderBit, Matrix(), null)//Draw the viewFinder
canvas.drawBitmap(frameBit, 0f, 0f, null)//Draw the frame
viewFinderBit.recycle()
frameBit.recycle()

return bitmapOverlay
}

```
I used the 

canvas.drawBitmap(bitmap1: Bitmap, Matrix(), null)

canvas.drawBitmap(bitmap2: Bitmap, 0, 0, null)
May I ask why the second line of canvas.drawBitmap(bitmap2: Bitmap, 0, 0, null) didn't overlay the whole original picture, but only overlay for the center of the preview?

Really appreciate for your helpful suggestion,

Sincerely, Leo

jags...@google.com 在 2022年8月22日 星期一清晨5:08:26 [UTC+8] 的信中寫道：