问题
I'm following this example :
package com.mtsahakis.mediaprojectiondemo;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.hardware.display.DisplayManager;
import android.hardware.display.VirtualDisplay;
import android.media.Image;
import android.media.ImageReader;
import android.media.projection.MediaProjection;
import android.media.projection.MediaProjectionManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Display;
import android.view.OrientationEventListener;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
public class ScreenCaptureImageActivity extends Activity {
private static final String TAG = ScreenCaptureImageActivity.class.getName();
private static final int REQUEST_CODE = 100;
private static String STORE_DIRECTORY;
private static int IMAGES_PRODUCED;
private static final String SCREENCAP_NAME = "screencap";
private static final int VIRTUAL_DISPLAY_FLAGS = DisplayManager.VIRTUAL_DISPLAY_FLAG_OWN_CONTENT_ONLY | DisplayManager.VIRTUAL_DISPLAY_FLAG_PUBLIC;
private static MediaProjection sMediaProjection;
private MediaProjectionManager mProjectionManager;
private ImageReader mImageReader;
private Handler mHandler;
private Display mDisplay;
private VirtualDisplay mVirtualDisplay;
private int mDensity;
private int mWidth;
private int mHeight;
private int mRotation;
private OrientationChangeCallback mOrientationChangeCallback;
private class ImageAvailableListener implements ImageReader.OnImageAvailableListener {
@Override
public void onImageAvailable(ImageReader reader) {
Image image = null;
FileOutputStream fos = null;
Bitmap bitmap = null;
try {
image = mImageReader.acquireLatestImage();
if (image != null) {
Image.Plane[] planes = image.getPlanes();
ByteBuffer buffer = planes[0].getBuffer();
int pixelStride = planes[0].getPixelStride();
int rowStride = planes[0].getRowStride();
int rowPadding = rowStride - pixelStride * mWidth;
// create bitmap
bitmap = Bitmap.createBitmap(mWidth + rowPadding / pixelStride, mHeight, Bitmap.Config.ARGB_8888);
bitmap.copyPixelsFromBuffer(buffer);
// write bitmap to a file
fos = new FileOutputStream(STORE_DIRECTORY + "/myscreen_" + IMAGES_PRODUCED + ".png");
bitmap.compress(CompressFormat.JPEG, 100, fos);
IMAGES_PRODUCED++;
Log.e(TAG, "captured image: " + IMAGES_PRODUCED);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (fos!=null) {
try {
fos.close();
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
if (bitmap!=null) {
bitmap.recycle();
}
if (image!=null) {
image.close();
}
}
}
}
private class OrientationChangeCallback extends OrientationEventListener {
public OrientationChangeCallback(Context context) {
super(context);
}
@Override
public void onOrientationChanged(int orientation) {
synchronized (this) {
final int rotation = mDisplay.getRotation();
if (rotation != mRotation) {
mRotation = rotation;
try {
// clean up
if(mVirtualDisplay != null) mVirtualDisplay.release();
if(mImageReader != null) mImageReader.setOnImageAvailableListener(null, null);
// re-create virtual display depending on device width / height
createVirtualDisplay();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
}
private class MediaProjectionStopCallback extends MediaProjection.Callback {
@Override
public void onStop() {
Log.e("ScreenCapture", "stopping projection.");
mHandler.post(new Runnable() {
@Override
public void run() {
if(mVirtualDisplay != null) mVirtualDisplay.release();
if(mImageReader != null) mImageReader.setOnImageAvailableListener(null, null);
if(mOrientationChangeCallback != null) mOrientationChangeCallback.disable();
sMediaProjection.unregisterCallback(MediaProjectionStopCallback.this);
}
});
}
}
/****************************************** Activity Lifecycle methods ************************/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// call for the projection manager
mProjectionManager = (MediaProjectionManager) getSystemService(Context.MEDIA_PROJECTION_SERVICE);
// start projection
Button startButton = (Button)findViewById(R.id.startButton);
startButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
startProjection();
}
});
// stop projection
Button stopButton = (Button)findViewById(R.id.stopButton);
stopButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
stopProjection();
}
});
// start capture handling thread
new Thread() {
@Override
public void run() {
Looper.prepare();
mHandler = new Handler();
Looper.loop();
}
}.start();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_CODE) {
sMediaProjection = mProjectionManager.getMediaProjection(resultCode, data);
if (sMediaProjection != null) {
File externalFilesDir = getExternalFilesDir(null);
if (externalFilesDir != null) {
STORE_DIRECTORY = externalFilesDir.getAbsolutePath() + "/screenshots/";
File storeDirectory = new File(STORE_DIRECTORY);
if (!storeDirectory.exists()) {
boolean success = storeDirectory.mkdirs();
if (!success) {
Log.e(TAG, "failed to create file storage directory.");
return;
}
}
} else {
Log.e(TAG, "failed to create file storage directory, getExternalFilesDir is null.");
return;
}
// display metrics
DisplayMetrics metrics = getResources().getDisplayMetrics();
mDensity = metrics.densityDpi;
mDisplay = getWindowManager().getDefaultDisplay();
// create virtual display depending on device width / height
createVirtualDisplay();
// register orientation change callback
mOrientationChangeCallback = new OrientationChangeCallback(this);
if (mOrientationChangeCallback.canDetectOrientation()) {
mOrientationChangeCallback.enable();
}
// register media projection stop callback
sMediaProjection.registerCallback(new MediaProjectionStopCallback(), mHandler);
}
}
}
/****************************************** UI Widget Callbacks *******************************/
private void startProjection() {
startActivityForResult(mProjectionManager.createScreenCaptureIntent(), REQUEST_CODE);
}
private void stopProjection() {
mHandler.post(new Runnable() {
@Override
public void run() {
if (sMediaProjection != null) {
sMediaProjection.stop();
}
}
});
}
/****************************************** Factoring Virtual Display creation ****************/
private void createVirtualDisplay() {
// get width and height
Point size = new Point();
mDisplay.getSize(size);
mWidth = size.x;
mHeight = size.y;
// start capture reader
mImageReader = ImageReader.newInstance(mWidth, mHeight, PixelFormat.RGBA_8888, 2);
mVirtualDisplay = sMediaProjection.createVirtualDisplay(SCREENCAP_NAME, mWidth, mHeight, mDensity, VIRTUAL_DISPLAY_FLAGS, mImageReader.getSurface(), null, mHandler);
mImageReader.setOnImageAvailableListener(new ImageAvailableListener(), mHandler);
}
}
to take a screenshot on Android ver >=21
.
The problem with that example is that once I take the screenshot , there are black edges on the top
, right
& bottom
of the Image
.
I can't see where is the problem since the given Width
and Height
to both the VirtualDisplay
and the Bitmap
are correct, what I'm missing here?
回答1:
Problem is probably the size of the virtual display.
mDisplay.getSize(size);
may return something different than the real size of the device if your device have a virtual navigation bar (usually swipe from bottom of the screen to display it).
mDisplay.getRealSize(size);
will probably fix your problem with black edges.
回答2:
Rect rect = image.getCropRect();
bitmap = Bitmap.createBitmap(bitmap, rect.left, rect.top, rect.width(), rect.height());
来源:https://stackoverflow.com/questions/37756298/black-edges-around-the-taken-screenshot