// 異步更新Image
    private class GetImageTask extends AsyncTask<String, Void, Bitmap> {

        // 覆寫的方法，這個方法將在這個類的對象execute()的時候調用
        protected Bitmap doInBackground(String... urls) {
            Bitmap bmp = null;
            Bitmap newBitmap = null;
            int bmWidth, bmHeight;
            try {
                bmp = FileUtil.getBitmapByPath(urls[0]);//本地圖片獲得Bitmap
                bmWidth = bmp.getWidth();
                bmHeight = bmp.getHeight();

                // 圖片過大就剪裁以下
                if ((bmWidth > 240) || (bmHeight > 240)) {
                    newBitmap = fileUtil.imageCropSquare(bmp);//從bitmap剪裁為正方形Bitmap
                } else {
                    newBitmap = bmp;
                }

            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return newBitmap;
        }

        @Override
        // 覆寫的方法，當耗時的操作執行完之后執行，這里就是把獲得的Bitmap更新到ImageView上
        protected void onPostExecute(Bitmap result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            imgPostPic.setImageBitmap(result);

        }

/**
     * 從本地路徑獲取、生成與原圖同樣大小的Bitmap，不作壓縮
     * 
     * @param path
     * @return
     */
    public static Bitmap getBitmapByPath(String path) {
        if (path == null){
            return null;
        }
        
        Bitmap bmTemp = null;
        if (bmTemp == null) {
            try {
                bmTemp = BitmapFactory.decodeFile(path);
            } catch (Exception e) {
                e.printStackTrace();
            } catch (Error e) {
                e.printStackTrace();
            }
        }
        return bmTemp;
    }

/**
     * Android獲取網絡圖片轉換成Bitmap
     * 
     * @return Bitmap
     */

    private static final int IO_BUFFER_SIZE = 4 * 1024;// 設置緩沖區大小

    public static Bitmap GetBitmapFromWeb(String url) {
        Bitmap bitmap = null;
        InputStream in = null;
        BufferedOutputStream out = null;
        try {
            System.out.println("GetLocalOrWebBitmap HEAD, url:" + url);
            in = new BufferedInputStream(new URL(url).openStream(),
                    IO_BUFFER_SIZE);
            final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
            out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE);
            copy(in, out);
            out.flush();
            byte[] data = dataStream.toByteArray();
            bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
            data = null;
            System.out.println("GetLocalOrWebBitmap END");
            return bitmap;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    // 附加的copy函數
    private static void copy(InputStream in, OutputStream out)
            throws IOException {
        byte[] b = new byte[IO_BUFFER_SIZE];
        int read;
        while ((read = in.read(b)) != -1) {
            out.write(b, 0, read);
        }
    }

/**
     * 按正方形裁切圖片

     */

    public  Bitmap imageCropSquare(Bitmap bitmap) {

        int w = bitmap.getWidth(); // 得到圖片的寬，高
        int h = bitmap.getHeight();
        int wh = w > h ? h : w;// 裁切后所取的正方形區域邊長
        int retX = w > h ? (w - h) / 2 : 0;//基于原圖，取正方形左上角x坐標
        int retY = w > h ? 0 : (h - w) / 2;

        //下面這句是關鍵

        return Bitmap.createBitmap(bitmap, retX, retY, wh, wh, null, false);

    }