这是onDraw的方法
protected void onDraw(Canvas canvas) {
canvas.drawColor(0xFFCCCCCC);
canvas.save();
canvas.concat(matrix);
paint.setShader(shader);

         canvas.drawVertices(Canvas.VertexMode.TRIANGLE_FAN, 10, verts, 0,
                                texs, 0, null, 0, indices, 0, 6, paint);
canvas.restore();
}
请问现在要怎么保存改变后的图片呢?谢谢