我正在从网址获取图像.我在listview中使用imageview.我想将位图图像列表添加到列表项的每一行.我使用SimpleAdapter但是imageview显示为空白.我的代码如下！

 ArrayList<HashMap<String, Bitmap>> mylist = new ArrayList<HashMap<String, Bitmap>>();

    Bundle bundle = this.getIntent().getExtras();
     get = bundle.getString("name");

     try{
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://www.propertyhookup.com/mobile/propertylist.php");
            nameValuePairs = new ArrayList<NameValuePair>(1);
            nameValuePairs.add(new BasicNameValuePair("zipcode", get.trim()));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();

    }catch(Exception e){
            Toast.makeText(getApplicationContext(), e.getMessage(), Toast.LENGTH_LONG).show();
    }

  //convert response to string
    try{
            BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");
            }
            is.close();
            result=sb.toString();
    }catch(Exception e){
            Toast.makeText(getApplicationContext(), e.getMessage(), Toast.LENGTH_LONG).show();
    }
    if(result.length()<= 7){
        Toast.makeText(getApplicationContext(), "No properties for this zipcode or check your zipcode ", Toast.LENGTH_LONG).show();
        //text.setText("No properties for this zipcode or check your zipcode");
    }
    else{
    try{

     jArray = new JSONObject(result);            
    }catch(JSONException e){
        Toast.makeText(getApplicationContext(), e.getMessage(), Toast.LENGTH_LONG).show();
    }

    //JSONObject json = JSONfunctions.getJSONfromURL("http://192.168.1.111/propertyhookup.com/mobile/propertylist.php");

    try{

        JSONArray  earthquakes = jArray.getJSONArray("earthquakes");

        for(int i=0;i<10;i++){                      
            map = new HashMap<String, Bitmap>();
            //HashMap<String, Drawable> map1 = new HashMap<String, Drawable>();

            JSONObject e = earthquakes.getJSONObject(i);



            if(e.getString("property_type").contains("1")) {
                proptype ="Single Family Home";
            }else if(e.getString("property_type").contains("2")) {
                proptype="Condo";
            }else if(e.getString("property_type").contains("3")) {
                proptype="Townhouse";
            }
            if(e.getString("estimated_price").contains("0")) {
                estimate = "Not Enough Market Value";
                //estimat = (TextView) findViewById(R.id.estimat);
                //estimat.setTextColor(Color.rgb(0, 0, 23));
            }else {
                estimate = "$"+e.getString("estimated_price");
            }

            photo = e.getString("photo1");

            drawable = LoadImageFromWebOperations(photo);

            //text.setImageDrawable(d);

            try
            {
                    aURL = new URL(photo);
            }
            catch (MalformedURLException e1)
            {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
            }
            URLConnection conn = null;
            try
            {
                    conn = aURL.openConnection();
            }
            catch (IOException e1)
            {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
            }
            try
            {
                    conn.connect();
            }
            catch (IOException e1)
            {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
            }
            InputStream is = null;
            try
            {
                    is = conn.getInputStream();
            }
            catch (IOException e1)
            {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
            }
            BufferedInputStream bis = new
    BufferedInputStream(is,8*1024);
            Bitmap bm = BitmapFactory.decodeStream(bis);

            map.put(photos, bm);
            mylist.add(map);


        }       
    }catch(JSONException e)        {
        Toast.makeText(getApplicationContext(),e.getMessage(), Toast.LENGTH_LONG).show();
    }



    SimpleAdapter adapter = new SimpleAdapter(this, mylist , R.layout.main4, 
                   new String[] { "percent","propertyid",  "cityname", "statecode", "propertytype", "footage", "bathroom", "bedroom", "price", "estimated", "photos" }, 
                   new int[] { R.id.percent, R.id.property_id,  R.id.city_name, R.id.state_code, R.id.prop_type, R.id.foot, R.id.bath, R.id.bed, R.id.list, R.id.estimat, R.id.image});
    setListAdapter(adapter);

解决方法:

我认为是因为你从网上下载图像,你需要在ASYNC中看到无痛的线索下载图像,然后刷新图像视图.