您可以使用位图以编程方式执行此操作:
首先在您的活动的 onCreate() 上执行此操作:
getSupportActionBar().setDisplayShowHomeEnabled(true);
Drawable drawable = new BitmapDrawable(getResources(), createCircleBitmap(sourceBitmap));
getSupportActionBar().setIcon(drawable);
这里是 createCircleBitmap() 方法:
public Bitmap createCircleBitmap(Bitmap bitmapimg){
Bitmap output = Bitmap.createBitmap(bitmapimg.getWidth(),
bitmapimg.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xff424242;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmapimg.getWidth(),
bitmapimg.getHeight());
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawCircle(bitmapimg.getWidth() / 2,
bitmapimg.getHeight() / 2, bitmapimg.getWidth() / 2, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmapimg, rect, rect, paint);
return output;
}
PS:如果你没有Bitmap,你可以用它把Drawable转成Bitmap:
Bitmap sourceBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.your_drawable);