关于bitmap的使用

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原创最新推荐文章于 2026-04-24 10:48:02 发布 567 阅读 AI 写同款· GEO 优化 ›

内核中bitmap的使用 bitmap用于实现bool的数组，标识一个事件发生没发生。可以理解为bitmap处理的是有没有的问题。bitmap将一片连续的空间作为一个数据类型，其中的成员都是1位，长度是bitmap的容量。声明一个 bitmap DECLARE_BITMAP 宏 #define DECLARE_BITMAP(name,bits) \ unsigned long name[BITS_TO_LONGS(bits)] #define BITS_TO_LONGS(nr) DIV_ROUND_UP(... 阅读详情

1.将bitmap转化为byte数组

ByteArrayOutputStream output = new ByteArrayOutputStream();//初始化一个流对象

bitmap.compress(CompressFormat.PNG, 100, output);//bitmap是Bitmap的对象把bitmap100%高质量压缩到 output对象里

byte[] result = output.toByteArray();

2.将byte数组转化为bitmap对象

 Resources res = getResources();

 Bitmap bitmap = BitmapFactory.decodeResource(res, R.drawable.icon);//先获取到Bitmap资源

 byte[] result = getIntent.getByteArrayExtra(bitmap);

 Bitmap bitmap = BitmapFactory.decodeByteArray(b,0,b.length);


3.将bitmap转化为Drawable
 Resources res = getResources();
 Bitmap bitmap = BitmapFactory.decodeResource(res, R.drawable.icon);//先获取到Bitmap资源
 Drawable drawable = new BitmapDrawable(bitmap);


4.Drawable → Bitmappublic static Bitmap drawableToBitmap(Drawable drawable) {
       
        Bitmap bitmap = Bitmap.createBitmap(
                                        drawable.getIntrinsicWidth(),
                                        drawable.getIntrinsicHeight(),
                                        drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
                                                        : Bitmap.Config.RGB_565);
        Canvas canvas = new Canvas(bitmap);
        //canvas.setBitmap(bitmap);
        drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
        drawable.draw(canvas);
        return bitmap;
}