Android 给图片加上水印的示例代码（支持logo+文字）

/**
 * 将一个view转换为Bitmap
 * @param view
 * @return
 */
public static Bitmap convertViewToBitmap(View view){
  view.measure(View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED), View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
  view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
  view.buildDrawingCache();
  Bitmap bitmap = view.getDrawingCache();
  return bitmap;
}

//根据原图处理要生成的水印的宽高
  float width = sourBitmap.getWidth();
  float height = sourBitmap.getHeight();
  float be = width / height;

  if ((float) 16 / 9 >= be && be >= (float) 4 / 3) {
    //在图片比例区间内16;9~4：3内，将生成的水印bitmap设置为原图宽高各自的1/5
    waterBitmap = WaterMaskUtil.zoomBitmap(waterBitmap, (int) width / 5, (int) height / 5);
  } else if (be > (float) 16 / 9) {
    //生成4：3的水印
    waterBitmap = WaterMaskUtil.zoomBitmap(waterBitmap, (int) width / 5, (int) width*3 / 20);
  } else if (be < (float) 4 / 3) {
    //生成4：3的水印
    waterBitmap = WaterMaskUtil.zoomBitmap(waterBitmap, (int) height*4 / 15, (int) height / 5);
  }

/**
 * 设置水印图片在左上角
 * @param src
 * @param watermark
 * @param paddingLeft
 * @param paddingTop
 * @return
 */
public static Bitmap createWaterMaskLeftTop(
    Context context, Bitmap src, Bitmap watermark,
    int paddingLeft, int paddingTop) {
  return createWaterMaskBitmap(src, watermark,
      dp2px(context, paddingLeft), dp2px(context, paddingTop));
}

/**
 * 设置水印图片在右下角
 * @param src
 * @param watermark
 * @param paddingRight
 * @param paddingBottom
 * @return
 */
public static Bitmap createWaterMaskRightBottom(
    Context context, Bitmap src, Bitmap watermark,
    int paddingRight, int paddingBottom) {
  return createWaterMaskBitmap(src, watermark,
      src.getWidth() - watermark.getWidth() - dp2px(context, paddingRight),
      src.getHeight() - watermark.getHeight() - dp2px(context, paddingBottom));
}

/**
 * 设置水印图片到右上角
 * @param src
 * @param watermark
 * @param paddingRight
 * @param paddingTop
 * @return
 */
public static Bitmap createWaterMaskRightTop(
    Context context, Bitmap src, Bitmap watermark,
    int paddingRight, int paddingTop) {
  return createWaterMaskBitmap( src, watermark,
      src.getWidth() - watermark.getWidth() - dp2px(context, paddingRight),
      dp2px(context, paddingTop));
}

/**
 * 设置水印图片到左下角
 * @param src
 * @param watermark
 * @param paddingLeft
 * @param paddingBottom
 * @return
 */
public static Bitmap createWaterMaskLeftBottom(
    Context context, Bitmap src, Bitmap watermark,
    int paddingLeft, int paddingBottom) {
  return createWaterMaskBitmap(src, watermark, dp2px(context, paddingLeft),
      src.getHeight() - watermark.getHeight() - dp2px(context, paddingBottom));
}

/**
 * 绘制水印图片
 * @param src 原图
 * @param watermark 水印
 * @param paddingLeft
 * @param paddingTop
 * @return
 */
private static Bitmap createWaterMaskBitmap(Bitmap src, Bitmap watermark,
                      int paddingLeft, int paddingTop) {
  if (src == null) {
    return null;
  }
  int width = src.getWidth();
  int height = src.getHeight();
  //创建一个bitmap
  Bitmap newb = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);// 创建一个新的和SRC长度宽度一样的位图
  //将该图片作为画布
  Canvas canvas = new Canvas(newb);
  //在画布 0，0坐标上开始绘制原始图片
  canvas.drawBitmap(src, 0, 0, null);
  //在画布上绘制水印图片
  canvas.drawBitmap(watermark, paddingLeft, paddingTop, null);
  // 保存
  canvas.save(Canvas.ALL_SAVE_FLAG);
  // 存储
  canvas.restore();
  return newb;
}