截图Android中的黑色(Screenshot Black in Android)

 我一直在研究如何在android中以编程方式截取屏幕截图，但是当它截图时，我会获得一个工具栏和黑屏，而不是屏幕上实际显示的内容。 
 
 我还试图在我为谷歌地图创建的自定义InfoWindow布局中截取特定的TextView。 但是这会在下面的第二行创建一个空指针异常。 
 
TextView v1 = (TextView)findViewById(R.id.tv_code);
v1.setDrawingCacheEnabled(true);
 
 无论如何要么实际屏幕截图屏幕上没有安装android截图库或在自定义InfoWindow布局中截图TextView 
 
 这是我的截图方法： 
 
/**
 * Method to take a screenshot programmatically
 */
private void takeScreenshot(){
    try {
        //TextView I could screenshot instead of the whole screen:
        //TextView v1 = (TextView)findViewById(R.id.tv_code);

        View v1 = getWindow().getDecorView().getRootView();
        v1.setDrawingCacheEnabled(true);
        Bitmap bitmap = Bitmap.createBitmap(v1.getDrawingCache());
        v1.setDrawingCacheEnabled(false);


        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 40, bytes);
        File f = new File(Environment.getExternalStorageDirectory()
                + File.separator + "test.jpg");

        FileOutputStream fo = new FileOutputStream(f);
        fo.write(bytes.toByteArray());
        fo.flush();
        fo.close();

        MediaStore.Images.Media.insertImage(getContentResolver(), f.getAbsolutePath(), f.getName(), f.getName());
        Log.d("debug", "Screenshot saved to gallery");

        Toast.makeText(HuntActivity.this,"Code Saved!",Toast.LENGTH_LONG).show();

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}
 
 编辑：我已将方法更改为源提供的方法 
 
 我如何以编程方式获取/合并谷歌地图v2的屏幕截图和xml的布局？ 
 
 但它没有截图任何东西。 
 
public void captureMapScreen() {
    GoogleMap.SnapshotReadyCallback callback = new GoogleMap.SnapshotReadyCallback() {

        @Override
        public void onSnapshotReady(Bitmap snapshot) {
            try {
                View mView = getWindow().getDecorView().getRootView();
                mView.setDrawingCacheEnabled(true);
                Bitmap backBitmap = mView.getDrawingCache();
                Bitmap bmOverlay = Bitmap.createBitmap(
                        backBitmap.getWidth(), backBitmap.getHeight(),
                        backBitmap.getConfig());

                Canvas canvas = new Canvas(bmOverlay);
                canvas.drawBitmap(backBitmap, 0, 0, null);
                canvas.drawBitmap(snapshot, new Matrix(), null);

                FileOutputStream out = new FileOutputStream(
                        Environment.getExternalStorageDirectory()
                                + "/"
                                + System.currentTimeMillis() + ".jpg");

                bmOverlay.compress(Bitmap.CompressFormat.JPEG, 90, out);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    };
    mMap.snapshot(callback);
}

I've been working out how to take a screenshot programmatically in android, however when it screenshots I get a toolbar and black screen captured instead of what is actually on the screen. 
 
I've also tried to screenshot a particular TextView within the custom InfoWindow layout I created for the google map. But that creates a null pointer exception on the second line below.
 
TextView v1 = (TextView)findViewById(R.id.tv_code);
v1.setDrawingCacheEnabled(true);
 
Is there anyway to either actually screenshot what is on the screen without installing android screenshot library or to screenshot a TextView within a custom InfoWindow layout
 
This is my screenshot method:
 
/**
 * Method to take a screenshot programmatically
 */
private void takeScreenshot(){
    try {
        //TextView I could screenshot instead of the whole screen:
        //TextView v1 = (TextView)findViewById(R.id.tv_code);

        View v1 = getWindow().getDecorView().getRootView();
        v1.setDrawingCacheEnabled(true);
        Bitmap bitmap = Bitmap.createBitmap(v1.getDrawingCache());
        v1.setDrawingCacheEnabled(false);


        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 40, bytes);
        File f = new File(Environment.getExternalStorageDirectory()
                + File.separator + "test.jpg");

        FileOutputStream fo = new FileOutputStream(f);
        fo.write(bytes.toByteArray());
        fo.flush();
        fo.close();

        MediaStore.Images.Media.insertImage(getContentResolver(), f.getAbsolutePath(), f.getName(), f.getName());
        Log.d("debug", "Screenshot saved to gallery");

        Toast.makeText(HuntActivity.this,"Code Saved!",Toast.LENGTH_LONG).show();

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}
 
EDIT: I have changed the method to the one provided from the source
 
How can i take/merge screen shot of Google map v2 and layout of xml both programmatically?
 
However it does not screenshot anything.
 
public void captureMapScreen() {
    GoogleMap.SnapshotReadyCallback callback = new GoogleMap.SnapshotReadyCallback() {

        @Override
        public void onSnapshotReady(Bitmap snapshot) {
            try {
                View mView = getWindow().getDecorView().getRootView();
                mView.setDrawingCacheEnabled(true);
                Bitmap backBitmap = mView.getDrawingCache();
                Bitmap bmOverlay = Bitmap.createBitmap(
                        backBitmap.getWidth(), backBitmap.getHeight(),
                        backBitmap.getConfig());

                Canvas canvas = new Canvas(bmOverlay);
                canvas.drawBitmap(backBitmap, 0, 0, null);
                canvas.drawBitmap(snapshot, new Matrix(), null);

                FileOutputStream out = new FileOutputStream(
                        Environment.getExternalStorageDirectory()
                                + "/"
                                + System.currentTimeMillis() + ".jpg");

                bmOverlay.compress(Bitmap.CompressFormat.JPEG, 90, out);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    };
    mMap.snapshot(callback);
}

原文：https://stackoverflow.com/questions/36878574