把一张图片decode成你想要的格式的bitmap

 

 

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new SampleView(this));

    }
    private static class SampleView extends View {
        private Bitmap mBitmap;
        public SampleView(Context context) {
            super(context);
            setFocusable(true);
            Bitmap bmp = null;
            String filePath = Environment.getExternalStorageDirectory().getAbsolutePath()+"/sx/852.png";
            BitmapFactory.Options options=new Options();
            options.inPreferredConfig = Bitmap.Config.ARGB_4444;
            bmp = BitmapFactory.decodeFile(filePath, options);
            Log.v(TAG,"decode success--threadid=="+Thread.currentThread().getId()+",name=="+Thread.currentThread().getName());
            mBitmap = bmp;
            //decodeStream 流
      /*      java.io.InputStream is;
            is = context.getResources().openRawResource(R.drawable.r8521);

            BitmapFactory.Options opts = new BitmapFactory.Options();
            Bitmap bm;

            opts.inPreferredConfig = Bitmap.Config.ARGB_4444;
            //opts.inPreferredConfig = Bitmap.Config.ARGB_8888;
            bm = BitmapFactory.decodeStream(is, null, opts);
            mBitmap = bm;*/
            // TODO Auto-generated constructor stub
        }
        @Override
        protected void onDraw(Canvas canvas) {
            // TODO Auto-generated method stub
            canvas.drawColor(0xFF000000);
            canvas.drawBitmap(mBitmap, 0, 0, null);
        }
        
    }

 

 

//当你想dump出来decode出来的bitmap数据的时候
String filename = “XXXXX”;      
FileOutputStream fos;
            try {
                fos = new FileOutputStream(filename);
                Bitmap b = mBitmap;
                b.compress(Bitmap.CompressFormat.PNG, 100, fos); //这样文件就保存到fileName目录下面了
            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

在AndroidManifest.xml别忘了配置读写权限

此段code完成：

1.把手机中的852.png decode成ARGB4444的bitmap

2.然后把bitmap画出来，看decode之后的效果