Android 将图片网址url转化为bitmap，drawable转bitmap，file转bitmap

file转bitmap

File param = new File();

Bitmap bitmap= BitmapFactory.decodeFile(param.getPath(）);

drawable转bitmap

Bitmap    bmp = BitmapFactory.decodeResource(getResources(),R.mipmap.jcss_03 );

url转bitmap

Bitmap bitmap;
public Bitmap returnBitMap(final String url){

    new Thread(new Runnable() {
        @Override
        public void run() {
            URL imageurl = null;

            try {
                imageurl = new URL(url);
            } catch (MalformedURLException e) {
                e.printStackTrace();
            }
            try {
                HttpURLConnection conn = (HttpURLConnection)imageurl.openConnection();
                conn.setDoInput(true);
                conn.connect();
                InputStream is = conn.getInputStream();
                bitmap = BitmapFactory.decodeStream(is);
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }).start();

    return bitmap;
}

可配合前台线程显示

private Handler mHandler = new Handler() {
    public void handleMessage(android.os.Message msg) {
        switch (msg.what) {
            case REFRESH_COMPLETE:
                myheadimage.setImageBitmap(bitmap);//显示
                break;
        }
    }
};

String imageUrl = "http://www.pp3.cn/uploads/201511/2015111212.jpg";
bitmap= returnBitMap(imageUrl);
mHandler.sendEmptyMessageDelayed(REFRESH_COMPLETE, 1000);