How to change default erase color in paint application in Android?

Question

I make an Application in which I want to erase drawing lines with event. For this I used

mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));

but at the time of erasing a line, that line becomes black first then erased. I want a transparent color for erasing a drawing a path.

Answer 1

I have gone through the FingerPaint.java from APIDemos i.e android-sdk\samples\android-17\ApiDemos

and modified

@Override
protected void onDraw(Canvas canvas) {
    canvas.drawColor(0xFFAAAAAA);

    canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);

    canvas.drawPath(mPath, mPaint);
}

to

@Override
protected void onDraw(Canvas canvas) {
   canvas.drawColor(0xFFAAAAAA);

   canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);

   mCanvas.drawPath(mPath, mPaint);  // this line changed 
                                     // mCanvas is Canvas variable which is
                                     // initialized in onSizeChanged()
}

Now it is not drawing a black color while erasing, everything works fine. Not sure it is 100% proper answer but it works for me.