Question

每个"KEY_PHOTO"中的密钥HashMap的值包含我需要放入R.id.imageView内的图片的网址，如何将网址转换为Bitmap？

public class MainActivity extends Activity {

    private static final String TAG = "TAG";
    ArrayList<HashMap<String, String>> usersHashMap;
    ListView listView;

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


        usersHashMap = new ArrayList<HashMap<String, String>>();
        listView = (ListView) findViewById(R.id.listView1);

        new readJson().execute();
    }


    class readJson extends AsyncTask<String, Void, String> {

        @Override
        protected void onPreExecute() {

            super.onPreExecute();
        }

        @Override
        protected String doInBackground(String... arg) {


            JSONParser jParser = new JSONParser();
            JSONObject json = null;
            json = jParser.getJSONFromUrl("link");

            try {
                JSONArray users = json.getJSONArray("users");
                for (int i = 0; i < users.length(); i++) {

                    JSONObject obj = users.getJSONObject(i);
                    HashMap<String, String> map = new HashMap<String, String>();

                    map.put("KEY_NAME", obj.getString("name"));
                    map.put("KEY_PHOTO", obj.getString("photo"));
                    map.put("KEY_AGE", obj.getString("age"));

                    usersHashMap.add(map);
                }

            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            Log.d(TAG, ""+json);

            return null;
        }

        @Override
        protected void onPostExecute(String result) {

            SimpleAdapter adapter = new SimpleAdapter(getApplicationContext(),  usersHashMap, R.layout.list_view,
                    new String[] { "KEY_NAME", "KEY_AGE", "KEY_PHOTO" },  
                    new int[] { R.id.list_headline,R.id.list_info,R.id.imageView }); //set photo url to R.id.imageView

            listView.setAdapter(adapter);

            super.onPostExecute(result);

        }

    }

}

Answer 1

使用HashMap键从"KEY_PHOTO"中提取值。然后，将下面的映射应用于该值以返回Bitmap。

您可以使用下面的代码段将字符串网址转换为Bitmap对象：

URL url = new URL(INSERT_STRING_URL_HERE);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setDoInput(true);
con.connect();
InputStream input = con.getInputStream();
Bitmap bitmap = BitmapFactory.decodeStream(input);

请务必使用网址字符串替换INSERT_STRING_URL_HERE。

在HashMap中将url转换为图像

1 个答案: