我已经为这个问题苦苦挣扎了 2 天...之前发帖但没有一个答案是正确的。

我的问题是:我正在尝试将 byte[] 转换为图像。 byte[] 来自 JSON，格式如下:

“4oCwUE5HDQoaCgAAAA1JSERSAAAfwAAAFAIBgAAADBHwqrDsAAAAAlwSFlzAAAAJwAAACcBKgnigJhPAAAgAElEQVR4xZPCrMK9ecWSZcOZfcOfw7c5w5vCvW/CqXp...”它再用 100 行。

显示图片的类:

public class PlayersListActivity extends Activity {

// URL to make request
private static String URL = "url goes here";
private static int userID;
ArrayList<HashMap<String, Object>> playersList;
ListView playerView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.list_view);

    Bundle extras = getIntent().getExtras();
    userID = extras.getInt("id");
    initLayout();
}

private void initLayout() {

    playerView = (ListView) findViewById(R.id.list);
    playersList = new ArrayList<HashMap<String, Object>>();

    playerView.setAdapter(new SimpleAdapter(PlayersListActivity.this, playersList, R.layout.activity_players_list, null, null));


    playerView.setDividerHeight(0);

}

@Override
protected void onResume() {
    if (!ConnectivityStatus.isNetworkAvailable(getApplicationContext())) {
        Toast.makeText(PlayersListActivity.this, R.string.network_failed,
                Toast.LENGTH_SHORT).show();
    } else {
        playerView.setAdapter(null);
        new PlayersLoadTask().execute();
    }

    super.onResume();
}

ProgressDialog pDialog;

class PlayersLoadTask extends AsyncTask<String, String, String> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(PlayersListActivity.this);
        pDialog.setMessage("Reading data");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
        playersList.clear();
    }
    @Override
    protected String doInBackground(String... arg0) {
        try {

        ArrayList<BasicNameValuePair> parameters = new ArrayList<BasicNameValuePair>();
        parameters.add(new BasicNameValuePair("request", "getPlayers"));
        parameters.add(new BasicNameValuePair("clubid", Integer.toString(userID))); // TODO: you'll need to change this to the Id from the user

        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost(PlayersListActivity.URL);
        httpPost.setEntity(new UrlEncodedFormEntity(parameters, "UTF-8"));
        HttpResponse httpResponse = httpClient.execute(httpPost);
        HttpEntity httpEntity = httpResponse.getEntity();

        // if this is null the web service returned an empty page
        if(httpEntity == null) // response is empty so exit out
            return null;

        String jsonString = EntityUtils.toString(httpEntity);

        // again some simple validation around the returned string
        if(jsonString != null && jsonString.length() != 0) // checking string returned from service to grab id
        {
            JSONArray jsonArray = new JSONArray(jsonString);
            for(int i=0; i< jsonArray.length(); i++)
            {   
                HashMap<String, Object> map = new HashMap<String, Object>();

                JSONObject jsonObject = (JSONObject) jsonArray.get(i);
                int id = jsonObject.getInt("id");
                String name = jsonObject.getString("name");
                byte[] image = jsonObject.getString("image").getBytes();
                String base64 = jsonObject.getString("image");
                try {
                    BitmapFactory.Options op=new BitmapFactory.Options();
                    op.inSampleSize=8;
                    Bitmap yourSelectedImage = BitmapFactory.decodeByteArray(image,0,image.length);
                    ByteArrayOutputStream baos = new ByteArrayOutputStream(); 

                    yourSelectedImage.compress(Bitmap.CompressFormat.PNG, 100, baos);
                    //this will convert image to byte[] 
                    byte[] byteArrayImage = baos.toByteArray(); 
                    // this will convert byte[] to string
                    String encodedImage = Base64.encodeToString(byteArrayImage, Base64.DEFAULT);
                    if (encodedImage != null) {

                       ImageView imgView = (ImageView) findViewById(R.id.image);
                       imgView.setImageBitmap(yourSelectedImage);
                    }

                } catch (Exception e) {
                    Log.d("Exception", e.toString());
                }
                //map.put("id", id);
                map.put("image", base64.toString());
                map.put("name", name);

                //Log.d("JSON OBJECTS:", jsonObject.toString());
                //Log.d("WHATS IN MAP:", map.toString());

                playersList.add(map);
            }

        }
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (JSONException e) {
        e.printStackTrace();
    } catch (Exception e) {
        Log.e("ERROR SOMEWHERE!!!! " , e.toString());
    }
    return null;

    }

    protected void onPostExecute(String file_url) {
        if(playersList.size() == 0 ) {
            Toast.makeText(PlayersListActivity.this, "No players in a list" , Toast.LENGTH_SHORT).show();
        } else {
            playerView.setAdapter(new PlayerListAdapter (PlayersListActivity.this, playersList, R.layout.activity_players_list, new String[] {"id", "image", "name"}, new int[] {R.id.player_list_id, R.id.image, R.id.name, }));
        }

        pDialog.dismiss();
    } 
}

还有 LogCat:

 D/skia(3513): --- SkImageDecoder::Factory returned null
 D/skia(3513): --- SkImageDecoder::Factory returned null
 E/BitmapFactory(4399): Unable to decode stream: java.io.FileNotFoundException: /4oCwUE5HDQoaCgAAAA1JSERSAAAAfwAAAFAIBgAAADBHwqrDsAAAAAlwSFlzAAAAJwAAACcBKgnigJhPAAAgAElEQVR4xZPCrMK9ecWSZcOZfcOfw7c5w5vCvW/CqXpLV...

我完全不知道为什么我的位图返回 null。我尝试了很多不同的方法，但没有任何效果。

这就是为什么我非常需要帮助!谢谢!!!

最佳答案

供以后引用

JSONArray jsonArray = new JSONArray(jsonString);
for (int i = 0; i < jsonArray.length(); i++) {
    HashMap<String, Object> map = new HashMap<String, Object>();
    JSONObject jsonObject = (JSONObject) jsonArray.get(i);
    int id = jsonObject.getInt("id");
    String name = jsonObject.getString("name");


    byte[] byteArray =  Base64.decode(jsonObject.getString("image"), Base64.DEFAULT) ;
    Bitmap bmp1 = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
    //Bitmap bitmap = Bitmap.createScaledBitmap(bmp1, 120, 120, false);


    map.put("id", id);
    map.put("name", name);

    map.put("image", bmp1);


    playersList.add(map);
    //Log.d("SHOW PLAYER LIST: " ,playersList.toString());
}

关于android - 如何将图像(字节数组)从 JSON 显示到 imageView 中...工厂返回 null，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/19767615/