BitmapFactory.Options&bitmap加灰色遮罩

最新推荐文章于 2021-05-26 06:06:41 发布

benjamin gao

最新推荐文章于 2021-05-26 06:06:41 发布

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分类专栏： bitmap 文章标签： BitmapFactory.Option

本文链接：https://blog.youkuaiyun.com/musk6/article/details/68941513

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该博客探讨了如何正确使用BitmapFactory.Options来仅读取图片尺寸，并展示了给Bitmap添加灰色遮罩的方法，包括两种不同的实现思路。还提供了未加灰色遮罩的代码效果对比，并链接到关于bitmap和canvas实现图层叠加的最新博客。

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----- 代码

① BitmapFactory.Options仅读取图片的尺寸参数的正确使用姿势

② 给bitmap加灰色遮罩

private void draw2layer(ImageView imageViewBlur2) {

        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeResource(getResources(), R.drawable.icon, options);
        int outWidth = options.outWidth;
        int outHeight = options.outHeight;

        Log.i(tag, "draw2layer: outWidth = " + outWidth + " ; outHeoght = " + outHeight);

        Bitmap bitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.RGB_565);
        Canvas canvas = new Canvas(bitmap);
        canvas.drawBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.icon, null), 0, 0, null);
        Canvas canvas1 = new Canvas(bitmap);
        canvas1.drawColor(0x33000000);
        imageViewBlur2.setImageBitmap(bitmap);
    }

----- 效果展示

-------未加灰色遮罩代码

        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeResource(getResources(), R.drawable.icon, options);
        int outWidth = options.outWidth;
        int outHeight = options.outHeight;

        Log.i(tag, "draw2layer: outWidth = " + outWidth + " ; outHeoght = " + outHeight);

        Bitmap bitmap = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.RGB_565);
        Canvas canvas = new Canvas(bitmap);
        canvas.drawBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.icon, null), 0, 0, null);
        imageView.setImageBitmap(bitmap);

----- 实现灰色遮罩的另外一种思路

最新blog：bitmap和canvas实现图层叠加

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