screenshot but creates blank file : android?

I am working on android. I have following code to capture a screenshot.

Setting up your Root layout:

View content = findViewById(R.id.layoutroot);
content.setDrawingCacheEnabled(true);

Function to get the rendered view:

private void getScreen()
{
    View content = findViewById(R.id.layoutroot);
    Bitmap bitmap = content.getDrawingCache();
    File file = new File("/sdcard/test.png");
    try 
    {
        file.createNewFile();
        FileOutputStream ostream = new FileOutputStream(file);
        bitmap.compress(CompressFormat.PNG, 100, ostream);
        ostream.close();
    } 
    catch (Exception e) 
    {
        e.printStackTrace开发者_开发百科();
    }
}

My problem is that it creates a zero kb file. what could be problem?

do these changes and try again:

• make the content variable a final and call findViewById on the layout of the activity

  final View content = somelayout.findViewById(R.id.layoutroot);

You have not write data to the file. you are directly closing the file thats why you got a file with 0 kb

use something like this

try 
    {
        file.createNewFile();
        FileOutputStream ostream = new FileOutputStream(file);
        byte[] mydata = null;//data in byte array
        ostream.write(mydata);
        ostream.close();
    } 
    catch (Exception e) 
    {
        e.printStackTrace();
    }