我正在尝试从不同的 url 在列表视图中显示图像，我从 jsonarray 接收我的 url 和其他详细信息，我从图形 api 获取这些信息，我从中将我的数据解析到列表并在列表视图中显示详细信息但是那个 jsonobject 给了我图像文件的 url，我想我需要先下载并显示而不是通过延迟加载，我正在按照这个教程进行延迟加载-http: //wptrafficanalyzer.in/blog/android-延迟加载图像和文本列表视图来自 http-json-data/。我在一个片段类中实现，并且在运行应用程序时它只是停止工作。我将非常感谢提供的任何帮助。
这是我的代码
Request request1 = new Request(session,"/fql",params,HttpMethod.GET,new Request.Callback()
{
public void onCompleted(Response response)
{
int indexex=nthOccurrence(response.getGraphObject().toString(),'{',1);
int index=response.getGraphObject().toString().length()-1;
String edit=response.getGraphObject().toString().substring(indexex, index);
try
{
JSONObject json = Util.parseJson(edit);
JSONArray data = json.getJSONArray( "data" );
JSONObject getVideo = data.getJSONObject(2);
String s="{data:"+getVideo.getString("fql_result_set")+"}";
JSONObject json1 = Util.parseJson(s);
JSONArray data1 = json1.getJSONArray("data");
ListViewLoaderTask listViewLoaderTask = new ListViewLoaderTask();
listViewLoaderTask.execute(data1);
}
catch(Exception e){
userNameView.setText(e.toString());
}
}
});
Request.executeBatchAsync(request1);
private class DisplayDetails extends AsyncTask<Session, Void, JSONArray>
{
Session session;
Request request1;
@Override
protected JSONArray doInBackground(Session...sessions)
{
session=sessions[0];
Request request = Request.newMeRequest(session, new Request.GraphUserCallback()
{
@Override
public void onCompleted(GraphUser user, Response response)
{
if (user != null)
{
profilePictureView.setProfileId(user.getId());
// Set the Textview's text to the user's name
userNameView.setText(user.getName());
}
}
});
Request.executeBatchAsync(request);
String fqlQuery = "{'myVideos':'SELECT vid, src, owner, title, description,thumbnail_link, created_time FROM video WHERE owner=me()'," +
"'friends':'SELECT uid2 FROM friend WHERE uid1 = me()',"+
"'friendsVideo':'SELECT vid, src, owner, title, description,thumbnail_link, created_time FROM video WHERE owner IN "+
"(SELECT uid2 FROM #friends) ORDER BY created_time',}";
Bundle params = new Bundle();
params.putString("q", fqlQuery);
Session session1 = Session.getActiveSession();
request1 = new Request(session,"/fql",params,HttpMethod.GET,new Request.Callback()
{
public void onCompleted(Response response)
{
int indexex=nthOccurrence(response.getGraphObject().toString(),'{',1);
int index=response.getGraphObject().toString().length()-1;
String edit=response.getGraphObject().toString().substring(indexex, index);
try
{
JSONObject json = Util.parseJson(edit);
JSONArray data = json.getJSONArray( "data" );
String fbGraph;
JSONObject getVideo = data.getJSONObject(2);
String s="{data:"+getVideo.getString("fql_result_set")+"}";
JSONObject json1 = Util.parseJson(s);
data1 = json1.getJSONArray("data");
}
catch(Exception e){}
}
});
return data1;
}
@Override
protected void onPostExecute(JSONArray data1)
{
ListViewLoaderTask listViewLoaderTask = new ListViewLoaderTask();
listViewLoaderTask.execute(data1);
Request.executeBatchAsync(request1);
}
}
private class ListViewLoaderTask extends AsyncTask<JSONArray, Void, SimpleAdapter>
{
JSONObject getVidDetails;
// Doing the parsing of xml data in a non-ui thread
@Override
protected SimpleAdapter doInBackground(JSONArray... data)
{
HashMap<String, Object> hm = new HashMap<String,Object>();
List<HashMap<String, Object>> videoDetails = null;
userNameView.setText("dsrf");
try{
for ( int i = 0, size = data1.length(); i < size; i++ )
{
getVidDetails=data[0].getJSONObject(i);
hm.put("title", "Title : " + getVidDetails.getString("title") );
DateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
hm.put("creationDate","Created On : " + formatter.format(Long.valueOf(getVidDetails.getString("created_time")).longValue()*1000));
hm.put("videoThumbnail", R.drawable.blank);
hm.put("thumbnail_path",getVidDetails.getString("thumbnail_link"));
hm.put("owner","Owner : " +getVidDetails.getString("owner") );
videoDetails.add(hm);
}
}catch(Exception e){
Log.d("JSON Exception1",e.toString());
}
String[] itemControl = {"videoThumbnail","title","creationDate","owner"};
int[] itemLayout={R.id.videoThumb,R.id.title,R.id.creationDate,R.id.owner};
SimpleAdapter adapter = new SimpleAdapter(getActivity().getBaseContext(), videoDetails, R.layout.listvideos_layout, itemControl, itemLayout);
return adapter;
}
*//** Invoked by the Android on "doInBackground" is executed *//*
@Override
protected void onPostExecute(SimpleAdapter adapter)
{
// Setting adapter for the listview
listView.setAdapter(adapter);
for(int i=0;i<adapter.getCount();i++){
HashMap<String, Object> hm = (HashMap<String, Object>) adapter.getItem(i);
String imgUrl = (String) hm.get("thumbnail_path");
ImageLoaderTask imageLoaderTask = new ImageLoaderTask();
HashMap<String, Object> hmDownload = new HashMap<String, Object>();
hm.put("thumbnail_path",imgUrl);
hm.put("position", i);
// Starting ImageLoaderTask to download and populate image in the listview
imageLoaderTask.execute(hm);
}
}
}
*//** AsyncTask to download and load an image in ListView *//*
private class ImageLoaderTask extends AsyncTask<HashMap<String, Object>, Void, HashMap<String, Object>>{
@Override
protected HashMap<String, Object> doInBackground(HashMap<String, Object>... hm) {
InputStream iStream=null;
String imgUrl = (String) hm[0].get("thumbnail_path");
int position = (Integer) hm[0].get("position");
URL url;
try {
url = new URL(imgUrl);
// Creating an http connection to communicate with url
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
// Connecting to url
urlConnection.connect();
// Reading data from url
iStream = urlConnection.getInputStream();
// Getting Caching directory
File cacheDirectory = getActivity().getBaseContext().getCacheDir();
// Temporary file to store the downloaded image
File tmpFile = new File(cacheDirectory.getPath() + "/wpta_"+position+".jpg");
// The FileOutputStream to the temporary file
FileOutputStream fOutStream = new FileOutputStream(tmpFile);
// Creating a bitmap from the downloaded inputstream
Bitmap b = BitmapFactory.decodeStream(iStream);
// Writing the bitmap to the temporary file as jpg file
b.compress(Bitmap.CompressFormat.JPEG,100, fOutStream);
// Flush the FileOutputStream
fOutStream.flush();
//Close the FileOutputStream
fOutStream.close();
// Create a hashmap object to store image path and its position in the listview
HashMap<String, Object> hmBitmap = new HashMap<String, Object>();
// Storing the path to the temporary image file
hmBitmap.put("videoThumbnail",tmpFile.getPath());
// Storing the position of the image in the listview
hmBitmap.put("position",position);
// Returning the HashMap object containing the image path and position
return hmBitmap;
}catch (Exception e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(HashMap<String, Object> result) {
// Getting the path to the downloaded image
String path = (String) result.get("videoThumbnail");
// Getting the position of the downloaded image
int position = (Integer) result.get("position");
// Getting adapter of the listview
SimpleAdapter adapter = (SimpleAdapter ) listView.getAdapter();
// Getting the hashmap object at the specified position of the listview
HashMap<String, Object> hm = (HashMap<String, Object>) adapter.getItem(position);
// Overwriting the existing path in the adapter
hm.put("videoThumbnail",path);
// Noticing listview about the dataset changes
adapter.notifyDataSetChanged();
}
}
我还添加了我的应用程序的日志 cat 文件-
12-22 16:08:41.371: W/dalvikvm(625): threadid=11: thread exiting with uncaught exception (group=0x409c01f8)
12-22 16:08:42.120: E/AndroidRuntime(625): FATAL EXCEPTION: AsyncTask #1
12-22 16:08:42.120: E/AndroidRuntime(625): java.lang.RuntimeException: An error occured while executing doInBackground()
12-22 16:08:42.120: E/AndroidRuntime(625): at android.os.AsyncTask$3.done(AsyncTask.java:278)
12-22 16:08:42.120: E/AndroidRuntime(625): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
12-22 16:08:42.120: E/AndroidRuntime(625): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
12-22 16:08:42.120: E/AndroidRuntime(625): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
12-22 16:08:42.120: E/AndroidRuntime(625): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
12-22 16:08:42.120: E/AndroidRuntime(625): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
12-22 16:08:42.120: E/AndroidRuntime(625): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
12-22 16:08:42.120: E/AndroidRuntime(625): at java.lang.Thread.run(Thread.java:856)
12-22 16:08:42.120: E/AndroidRuntime(625): Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
12-22 16:08:42.120: E/AndroidRuntime(625): at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:4039)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:709)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.view.View.requestLayout(View.java:12675)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.view.View.requestLayout(View.java:12675)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.view.View.requestLayout(View.java:12675)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.view.View.requestLayout(View.java:12675)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.view.View.requestLayout(View.java:12675)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.view.View.requestLayout(View.java:12675)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.widget.RelativeLayout.requestLayout(RelativeLayout.java:268)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.view.View.requestLayout(View.java:12675)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.widget.TextView.checkForRelayout(TextView.java:6773)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.widget.TextView.setText(TextView.java:3306)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.widget.TextView.setText(TextView.java:3162)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.widget.TextView.setText(TextView.java:3137)
12-22 16:08:42.120: E/AndroidRuntime(625): at com.socialsober.LogFragment$ListViewLoaderTask.doInBackground(LogFragment.java:267)
12-22 16:08:42.120: E/AndroidRuntime(625): at com.socialsober.LogFragment$ListViewLoaderTask.doInBackground(LogFragment.java:1)
12-22 16:08:42.120: E/AndroidRuntime(625): at android.os.AsyncTask$2.call(AsyncTask.java:264)
12-22 16:08:42.120: E/AndroidRuntime(625): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
12-22 16:08:42.120: E/AndroidRuntime(625): ... 5 more
12-22 16:08:43.341: W/ActivityManager(77): Force finishing activity com.socialsober/.MainActivity
12-22 16:08:43.341: W/WindowManager(77): Failure taking screenshot for (180x300) to layer 21010
12-22 16:08:43.861: W/ActivityManager(77): Activity pause timeout for ActivityRecord{416f0a08 com.socialsober/.MainActivity}