获取view的图片

private Bitmap loadBitmapFromView(View v) {
int w = v.getWidth();
int h = v.getHeight();
Bitmap bmp = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bmp);
c.drawColor(Color.WHITE);
/** 如果不设置canvas画布为白色，则生成透明 */
// v.layout(0, 0, w, h);
v.draw(c);
return bmp;
}