I need to convert a view to a bitmap to preview my view and to save it as an image. I tried using the following code, but it creates a blank image. I cannot understand where I made a mistake.

 View viewToBeConverted;  Bitmap viewBitmap =   Bitmap.createBitmap(viewToBeConverted.getWidth(), viewToBeConverted.getHeight(),Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(viewBitmap); 
 viewToBeConverted.draw(canvas); 
 savephoto(“f1”, viewBitmap); 

 ////  public void savephoto(String filename,Bitmap bit)     
   {  
            File newFile = new File(Environment.getExternalStorageDirectory() + Picture_Card/"+ filename+ ".PNG");
              try 
{
                    newFile.createNewFile();                   
 try
 { 
                         FileOutputStream pdfFile = new FileOutputStream(newFile);                                                Bitmap bm = bit;                          ByteArrayOutputStream baos = new ByteArrayOutputStream();                          bm.compress(Bitmap.CompressFormat.PNG,100, baos);                                                     byte[] bytes = baos.toByteArray();                         
 pdfFile.write(bytes);                                              
      pdfFile.close();                   
 }
 catch (FileNotFoundException e) 
{                          //       

  }            
  } catch (IOException e)
 {                    //          
    }      
  }  

Solution 1

here is my solution:

  public static Bitmap getBitmapFromView(View view) {
        //Define a bitmap with the same size as the view
        Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(),Bitmap.Config.ARGB_8888);
        //Bind a canvas to it
        Canvas canvas = new Canvas(returnedBitmap);
        //Get the view's background
        Drawable bgDrawable =view.getBackground();
        if (bgDrawable!=null) 
            //has background drawable, then draw it on the canvas
            bgDrawable.draw(canvas);
        else 
            //does not have background drawable, then draw white background on the canvas
            canvas.drawColor(Color.WHITE);
        // draw the view on the canvas
        view.draw(canvas);
        //return the bitmap
        return returnedBitmap;
    }

Enjoy :)

Solution 2

The most voted solution did not work for me because my view is a ViewGroup(have been inflated from a LayoutInflater). I needed to call view.measure to force the view size to be calculated in order to get the correct view size with view.getMeasuredWidth(Height).

public static Bitmap getBitmapFromView(View view) {
    view.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
    Bitmap bitmap = Bitmap.createBitmap(view.getMeasuredWidth(), view.getMeasuredHeight(),
            Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
    view.draw(canvas);
    return bitmap;
}

Solution 3

use new kotlin extention function view.drawToBitmap()

mLayout.drawToBitmap()

Solution 4

Here is extension in Kotlin inspired by : Google Android Maps Utils Icon Generator

fun View.convertToBitmap(): Bitmap {
val measureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED)
measure(measureSpec, measureSpec)
layout(0, 0, measuredWidth, measuredHeight)
val r = Bitmap.createBitmap(measuredWidth, measuredHeight, Bitmap.Config.ARGB_8888)
r.eraseColor(Color.TRANSPARENT)
val canvas = Canvas(r)
draw(canvas)
return r }

Solution 5

All answers using drawing on the canvas won't work with a GLSurfaceView.

To capture the content of a GLSurfaceView into a bitmap you should consider to implement a custom method with gl.glReadPixels inside Renderer::onDrawFrame().

A solution snippet has been posted here.

Solution 6

Conversion of Layout or view to bitmap :

  private Bitmap createBitmapFromLayout(View tv) {        
    int spec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    tv.measure(spec, spec);
    tv.layout(0, 0, tv.getMeasuredWidth(), tv.getMeasuredHeight());
    Bitmap b = Bitmap.createBitmap(tv.getMeasuredWidth(), tv.measuredHeight(),
            Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(b);
    c.translate((-tv.getScrollX()), (-tv.getScrollY()));
    tv.draw(c);
    return b;
}

Without xml:

  private Bitmap createBitmapFromView() {
    TextView tv = new TextView(this);
    tv.setText("Hello Android !!");
    tv.setTextColor(Color.WHITE);
    tv.setBackgroundColor(Color.GRAY);
    int spec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
    tv.measure(spec, spec);
    tv.layout(0, 0, tv.getMeasuredWidth(), tv.getMeasuredHeight());
    Bitmap b = Bitmap.createBitmap(tv.getMeasuredWidth(), tv.measuredHeight(),
            Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(b);
    c.translate((-tv.getScrollX()), (-tv.getScrollY()));
    tv.draw(c);
    return b;
}

Solution 7

since API level 24 there is a better way with PixelCopy example of use:

/**
 * use [PixelCopy] to take a snap shoot of the given view
 */
fun copyViewPixelsToBitmap(window: Window?, view: View): Bitmap {
    val snap = Bitmap.createBitmap(view.width, view.height, Bitmap.Config.ARGB_8888)

    val listener = PixelCopy.OnPixelCopyFinishedListener {
        if (it != PixelCopy.SUCCESS) {
            Log.d("copyViewPixelsToBitmap failed with error: $it")
        }
    }
    val xy = IntArray(2)
    view.getLocationInWindow(xy)

    val rect = Rect(xy[0], xy[1], xy[0] + view.width, xy[1] + view.height)
    window?.let {
        PixelCopy.request(it, rect, snap, listener,
            Handler(Looper.getMainLooper()))
    }
    return snap
}

Solution 8

To get a bitmap exactly as it is shown on the screen, you can use the view after it has been displayed with a Runnable:



void viewToBitmap(View view) {
  view.post(new Runnable() {
      @Override
      public void run() {
        Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        view.draw(canvas);
        
        // Do stuff
      }
  });
}