Null Pointer Exception on Bitmap bitmap = content.getDrawingCache();

Question

I'm trying to create an app which allows users to screenshot the current view. I'm using the following code to do so.

View content = ((Activity)ctx).findViewById(R.id.rootlayout);
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();
}

However, i'm getting a Null Pointer Exception on the following line:

Bitmap bitmap = content.getDrawingCache();

What would this mean, that the view is empty?

Any help would be great!

DeeV · Accepted Answer · 2011-11-15 13:43:29Z

2

You need to call content.setDrawingCacheEnabled(true); before you can use that. Then call content.setDrawingCacheEnabled(false); when you're done.

answered Nov 15, 2011 at 13:43

DeeV

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