How to take snapshot of screen not only app in Android with code

Question

I've developed app that takes screenshot. But it only takes snapshot of app. I want to take snapshot out of app. I've researched answers but I don't find answer yet. Here is my code.

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

saveImagetoAppFolder is function that saves image to app folder. That's not problem. Is there anyway to take snapshot of screen?

Answer 1

To take screen shot of the device screen, Only if you have root call the screencap binary like:

Process sh = Runtime.getRuntime().exec("su", null,null);
OutputStream  os = sh.getOutputStream();
os.write(("/system/bin/screencap -p " + Environment.getExternalStorageDirectory()+ "/img.png").getBytes("ASCII"));
os.flush();
os.close();
sh.waitFor()

And to load that file into a bitmap,Use

public static Bitmap decodeSampledBitmapFromFile(String path,
                                                     int reqWidth, int reqHeight) {

        // First decode with inJustDecodeBounds=true to check dimensions
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        return BitmapFactory.decodeFile(path, options);
    }

    public static int calculateInSampleSize(
            BitmapFactory.Options options, int reqWidth, int reqHeight) {
        // Raw height and width of image
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {

            final int halfHeight = height / 2;
            final int halfWidth = width / 2;

            // Calculate the largest inSampleSize value that is a power of 2 and keeps both
            // height and width larger than the requested height and width.
            while ((halfHeight / inSampleSize) > reqHeight
                    && (halfWidth / inSampleSize) > reqWidth) {
                inSampleSize *= 2;
            }
        }

        return inSampleSize;
    }

Answer 2

i don't know your code in saveImageToAppFolder is what but you can try this:

Note: you need set background of your app/activity to transparent (100%).

 //your code below is extractly
View view = getWindow().getDecorView().getRootView();
view.setDrawingCacheEnabled(true);
Bitmap bitmap = Bitmap.createBitmap(view.getDrawingCache());
view.setDrawingCacheEnabled(false);

  //try my code for save image file to storage   
  File imgFile = new File(imgPath);

        FileOutputStream os = new FileOutputStream(imageFile);
        int imgQuality = 100;
        bitmap.compress(Bitmap.CompressFormat.JPEG, imgQuality , os);
        os.flush();
        os.close();

Code to set transparent background:

//first: create theme xml below for transparent

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <style name="Theme.Transparent" parent="android:Theme">
    <item name="android:windowIsTranslucent">true</item>
    <item name="android:windowBackground">@android:color/transparent</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowIsFloating">true</item>
    <item name="android:backgroundDimEnabled">false</item>
  </style>
</resources>

after set by this way:

<activity android:name=".SampleActivity" android:theme="@style/Theme.Transparent">

</activity>

note: you can red more detail from here url: How do I create a transparent Activity on Android?