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This article mainly introduces the relevant knowledge of "Android5.0 and above how to achieve screen capture function". The editor shows you the operation process through an actual case. The operation method is simple, fast and practical. I hope this article "how to achieve screen capture function in Android5.0 and above" can help you solve the problem.

one。 Related classes involved

1. MediaProjectionManager

Official words: Manages the retrieval of certain types of {@ link MediaProjection} tokens.

This class is obtained through MEDIA_PROJECTION_SERVICE in Context#getSystemService, and its function is to get MediaProjection

2. MediaProjection

Official words: A token granting applications the ability to capture screen contents and/or record system audio. The exact capabilities granted depend on the type of MediaProjection. We can get the contents of the screen in this class.

3. ImageReader

Official words: The ImageReader class allows direct application access to image data

Rendered into a {@ link android.view.Surface}

Through this class, we can convert Surface into pictures.

two。 The above three classes can complete our operation of capturing screen images, so we will explain how they work together.

1. First of all, obtain the user's authorization. The screenshot screen needs to be authorized manually before it can be operated.

@ TargetApi (Build.VERSION_CODES.LOLLIPOP) public void requestCapturePermission () {if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {/ / 5.0Screenshot return;} MediaProjectionManager mediaProjectionManager = (MediaProjectionManager) getSystemService (Context.MEDIA_PROJECTION_SERVICE); startActivityForResult (mediaProjectionManager.createScreenCaptureIntent (), REQUEST_MEDIA_PROJECTION);}

StartActivityForResult must be used here because the result of user authorization to capture the screen is returned in the createScreenCaptureIntent () method, and the user allows or denies it according to the pop-up window below.

After selection, the user operates the returned result data in the onActivityResult of Activity.

@ Overrideprotected void onActivityResult (int requestCode, int resultCode, Intent data) {super.onActivityResult (requestCode, resultCode, data); switch (requestCode) {case REQUEST_MEDIA_PROJECTION: if (resultCode = = RESULT_OK & & data! = null) {FloatWindowsService.setResultData (data); startService (new Intent (getApplicationContext (), FloatWindowsService.class);} break;}}

Here I am using FloatWindowsService to display a floating button on the desktop. Click on the screenshot. Let's see how to achieve the screenshot in FloatWindowsService.

two。 Capture the contents of the screen to generate Bitmap

First create an ImageReader instance

Private void createImageReader () {mImageReader = ImageReader.newInstance (mScreenWidth, mScreenHeight, PixelFormat.RGBA_8888, 2);}

Then click on the event to trigger startScreenShot ()

Private void startScreenShot () {mFloatView.setVisibility (View.GONE); Handler handler = new Handler (); handler.postDelayed (new Runnable () {public void run () {/ / get the current screen content startVirtual ();}}, 5); handler.postDelayed (new Runnable () {public void run () {/ / generate picture to local startCapture ();}}, 30);}

One thing we do in the startVirtual () method is to get the current screen content

Public void startVirtual () {if (mMediaProjection! = null) {virtualDisplay ();} else {setUpMediaProjection (); virtualDisplay ();}}

At the same time, you need to obtain the MediaProjection instance, and mResultData is the result returned after authorization.

Public void setUpMediaProjection () {if (mResultData = = null) {Intent intent = new Intent (Intent.ACTION_MAIN); intent.addCategory (Intent.CATEGORY_LAUNCHER); startActivity (intent);} else {/ / mResultData is the result mMediaProjection = getMediaProjectionManager (). GetMediaProjection (Activity.RESULT_OK, mResultData) returned after user authorization in Activity;}}

Finally get the content of the current screen. Notice that mImageReader.getSurface () is passed in here, and the screen data will also be in the Surface in ImageReader.

Private void virtualDisplay () {mVirtualDisplay = mMediaProjection.createVirtualDisplay ("screen-mirror", mScreenWidth, mScreenHeight, mScreenDensity, DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR, mImageReader.getSurface (), null, null);}

Finally, the screen content data obtained by mImageReader is converted into pictures and processed in AsyncTask.

The buffer data in Image.Plane is not exactly what Bitmap needs, so you need to pay attention to the following three points

1. The picture format set by Image must be consistent with that set by Bitmap.

two。 There is row spacing in the buffer data, so we have to remove these gaps

3. After using Image, you must call image.close (); close it, otherwise you will report an error if you use it again.

@ Overrideprotected Bitmap doInBackground (Image... Params) {if (params = = null | | params.length < 1 | params [0] = = null) {return null;} Image image = params [0]; int width = image.getWidth (); int height = image.getHeight (); final Image.Plane [] planes = image.getPlanes (); final ByteBuffer buffer = planes [0] .getBuffer (); / / spacing per pixel int pixelStride = planes [0] .getPixelStride (); / / Total spacing int rowStride = planes [0] .getRowStride () Int rowPadding = rowStride-pixelStride * width; Bitmap bitmap = Bitmap.createBitmap (width + rowPadding / pixelStride, height, Bitmap.Config.ARGB_8888); bitmap.copyPixelsFromBuffer (buffer); bitmap = Bitmap.createBitmap (bitmap, 0,0, width, height); image.close ()

Finally, save the generated bitmap and ok it.

This is the end of the introduction on "how to achieve screen capture function in Android5.0 and above". Thank you for your reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.

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