从未调用过自定义适配器 getView()

Question

我有一个用于列表视图的自定义 ArrayAdapter。当我设置列表适配器时，不会调用 getView。我已经返回了计数，并且计数应该是（不是 0）。我还记录了不同的项目位置，以确保适配器有数据要显示，但仍然没有调用 getview。我在异步任务的 postExecute() 中设置了列表适配器。似乎除了 getView 之外的所有东西都被调用了。这是代码

private class StableArrayAdapter extends ArrayAdapter<String> {

        private final Context context;
        private List<String> viewString;
        private ImageView image;
        private TextView addToCalendarButton;
        private TextView eventTitle;
        private ImageView eventImage;
        private TextView likesTV;
        private TextView planToAttendTV;

        public StableArrayAdapter(Context context, List<String> strings) {
            super(context, R.layout.post_layout, strings);
            this.context = context;
            this.viewString = strings;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View postLayout = inflater.inflate(R.layout.post_layout, parent, false);

            TextView unameTV = (TextView)postLayout.findViewById(R.id.postUnameTv);
            unameTV.setText(viewString.get(0));

            image = (ImageView)postLayout.findViewById(R.id.postProfPic);
            DisplayImageOptions options = initiateDisplayImageOptions();
            ImageLoader imageloader = ImageLoader.getInstance();
            initImageLoader(getActivity());
            imageloader.displayImage(viewString.get(1), image, options);


            addToCalendarButton = (TextView)postLayout.findViewById(R.id.addToCalendarButton);
            addToCalendarButton.setText(viewString.get(2));

            eventTitle = (TextView)postLayout.findViewById(R.id.postTitleTV);
            eventTitle.setText(viewString.get(3));

            eventImage = (ImageView)postLayout.findViewById(R.id.eventImage);
            imageloader.displayImage(viewString.get(4), eventImage, options);


            likesTV = (TextView)postLayout.findViewById(R.id.likesTV);
            likesTV.setText(""+viewContent.get(5));

            planToAttendTV = (TextView)postLayout.findViewById(R.id.planToAttendTV);
            planToAttendTV.setText(viewString.get(6));

            Log.d("Adapter", ""+viewString.get(6));



            return postLayout;
        }


        @Override
        public int getCount()
        {
            return viewString.size();
        }

        @Override
        public String getItem(int position) {
            return viewString.get(position);
        }

    }

}`

我不确定这是否是一个原因，但这是我在 postExecute 中设置列​​表适配器的方式

            getActivity().runOnUiThread(new Runnable() {
            public void run() {


                /**
                 * Updating parsed JSON data into ListView
                 * */

                StableArrayAdapter adapter = new StableArrayAdapter(getActivity(), viewContent);
                // updating listview

                lv.setAdapter(adapter);
                adapter.notifyDataSetChanged();


            }
        });

编辑 这是我用来获取数据的异步任务

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

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();

    }

    /**
     * getting All products from url
     * */
    protected String doInBackground(String... args) {
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        // getting JSON string from URL
        JSONObject json = jParser.makeHttpRequest(url_get_events, "GET", params);

        // Check your log cat for JSON reponse
        Log.d("Loading Events: ", "Loading Events...");

        try {
            // Checking for SUCCESS TAG
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {

                // products found
                // Getting Array of Products
                products = json.getJSONArray(TAG_PRODUCTS);


                // looping through All Products
                for (int i = 0; i < products.length(); i++) {

                    JSONObject c = products.getJSONObject(i);

                    // Storing each json item in variable
                    int id = c.getInt("id");
                    String name = c.getString("name");
                    String radius = c.getString("radius");

                    String centerlat = c.getString("centerlat");
                    String centerlng = c.getString("centerlng");

                    String topleftcornerlat = c.getString("topleftcornerlat");
                    String topleftcornerlng = c.getString("topleftcornerlng");

                    String bottomleftcornerlat = c.getString("bottomleftcornerlat");
                    String bottomleftcornerlng = c.getString("bottomleftcornerlng");

                    String bottomrightcornerlat = c.getString("bottomrightcornerlat");
                    String bottomrightcornerlng = c.getString("bottomrightcornerlng");




                    String startmonth = c.getString("startmonth");
                    String endmonth = c.getString("endmonth");

                    String startday= c.getString("startday");
                    String endday = c.getString("endday");

                    String startyear = c.getString("startyear");
                    String endyear = c.getString("endyear");

                    String starthour = c.getString("starthour");
                    String endhour= c.getString("endhour");

                    String startmins = c.getString("startmins");
                    String endmins= c.getString("endmins");




                    String attending_future = c.getString("attending_future");
                    String attending_now = c.getString("attending_now");

                    String likes = c.getString("likes");
                    String image = c.getString("image");

                    String profile = c.getString("profile");

                    String userprofilepic = c.getString("userprofpic");
                    String username = c.getString("username");


                    viewContent.add(username);


                    viewContent.add(userprofilepic);


                    String date = getMonth(Integer.parseInt(startmonth)) + " " + startday + ", " + startyear;

                    viewContent.add(date);


                    viewContent.add(name);


                    viewContent.add(image);
                    viewContent.add(""+likes);


                    viewContent.add(attending_future + " people plan to attend.");



                }
            } else {
                // no products found
                // Launch Add New product Activity
                /*
                Intent i = new Intent(getApplicationContext(),
                        NewProductActivity.class);
                // Closing all previous activities
                i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(i);
                */
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        Log.d("Loading Events: ", "Events Loaded");
        // dismiss the dialog after getting all products
        // updating UI from Background Thread


        getActivity().runOnUiThread(new Runnable() {
            public void run() {


                /**
                 * Updating parsed JSON data into ListView
                 * */

                StableArrayAdapter adapter = new StableArrayAdapter(getActivity(), viewContent);
                // updating listview

                lv.setAdapter(adapter);
                adapter.notifyDataSetChanged();


            }
        });

    }

编辑

这是完整的代码

public class MainFeed extends Fragment {

// Progress Dialog
private ProgressDialog pDialog;

// Creating JSON Parser object
JSONParser jParser = new JSONParser();
static List<String> viewContent = new ArrayList<>();

static Bundle bundle;
ArrayList<HashMap<String, String>> productsList;

// url to get all products list
private static String url_get_events = "http://127.0.0.1/get_events.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_PID = "pid";
private static final String TAG_NAME = "name";

// products JSONArray
JSONArray products = null;
private ListView lv;

/* (non-Javadoc)
 * @see android.support.v4.app.Fragment#onCreateView(android.view.LayoutInflater, android.view.ViewGroup, android.os.Bundle)
 */
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    bundle = savedInstanceState;

    inflater = getLayoutInflater(savedInstanceState);
    View view=inflater.inflate(R.layout.main_feed_layout, null);

    // Loading products in Background Thread
    new LoadAllProducts().execute();

    // Get listview
    lv = (ListView) view.findViewById(R.id.listView);


    // on seleting single product
    // launching Edit Product Screen
    lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

            /*
            String pid = ((TextView) view.findViewById(R.id.pid)).getText()
                    .toString();

            // Starting new intent
            Intent in = new Intent(getApplicationContext(),
                    EditProductActivity.class);
            // sending pid to next activity
            in.putExtra(TAG_PID, pid);

            // starting new activity and expecting some response back
            startActivityForResult(in, 100);
            */
        }
    });

    ImageLoadingListener progressListener = new ImageLoadingListener() {
        @Override
        public void onLoadingStarted(String s, View view) {
            Log.i("Start", "Start");
        }

        @Override
        public void onLoadingFailed(String s, View view, FailReason failReason) {
            Log.i("Start", "Failed");

        }

        @Override
        public void onLoadingComplete(String s, View view, Bitmap bitmap) {
        }

        @Override
        public void onLoadingCancelled(String s, View view) {
            Log.i("Start", "Cancelled");

        }
    };




    if (container == null) {

        return null;
    }
    return (RelativeLayout) inflater.inflate(R.layout.main_feed_layout, container, false);

}

// Response from Edit Product Activity
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    // if result code 100
    if (resultCode == 100) {
        // if result code 100 is received
        // means user edited/deleted product
        // reload this screen again
        Intent intent = data;
        //finish();
        startActivity(intent);
    }

}

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

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();

    }

    /**
     * getting All products from url
     * */
    protected String doInBackground(String... args) {
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        // getting JSON string from URL
        JSONObject json = jParser.makeHttpRequest(url_get_events, "GET", params);

        // Check your log cat for JSON reponse
        Log.d("Loading Events: ", "Loading Events...");

        try {
            // Checking for SUCCESS TAG
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {

                // products found
                // Getting Array of Products
                products = json.getJSONArray(TAG_PRODUCTS);


                // looping through All Products
                for (int i = 0; i < products.length(); i++) {

                    JSONObject c = products.getJSONObject(i);

                    // Storing each json item in variable
                    int id = c.getInt("id");
                    String name = c.getString("name");
                    String radius = c.getString("radius");

                    String centerlat = c.getString("centerlat");
                    String centerlng = c.getString("centerlng");

                    String topleftcornerlat = c.getString("topleftcornerlat");
                    String topleftcornerlng = c.getString("topleftcornerlng");

                    String bottomleftcornerlat = c.getString("bottomleftcornerlat");
                    String bottomleftcornerlng = c.getString("bottomleftcornerlng");

                    String bottomrightcornerlat = c.getString("bottomrightcornerlat");
                    String bottomrightcornerlng = c.getString("bottomrightcornerlng");




                    String startmonth = c.getString("startmonth");
                    String endmonth = c.getString("endmonth");

                    String startday= c.getString("startday");
                    String endday = c.getString("endday");

                    String startyear = c.getString("startyear");
                    String endyear = c.getString("endyear");

                    String starthour = c.getString("starthour");
                    String endhour= c.getString("endhour");

                    String startmins = c.getString("startmins");
                    String endmins= c.getString("endmins");




                    String attending_future = c.getString("attending_future");
                    String attending_now = c.getString("attending_now");

                    String likes = c.getString("likes");
                    String image = c.getString("image");

                    String profile = c.getString("profile");

                    String userprofilepic = c.getString("userprofpic");
                    String username = c.getString("username");


                    viewContent.add(username);


                    viewContent.add(userprofilepic);


                    String date = getMonth(Integer.parseInt(startmonth)) + " " + startday + ", " + startyear;

                    viewContent.add(date);


                    viewContent.add(name);


                    viewContent.add(image);
                    viewContent.add(""+likes);


                    viewContent.add(attending_future + " people plan to attend.");



                }
            } else {
                // no products found
                // Launch Add New product Activity
                /*
                Intent i = new Intent(getApplicationContext(),
                        NewProductActivity.class);
                // Closing all previous activities
                i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(i);
                */
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        Log.d("Loading Events: ", "Events Loaded");
        // dismiss the dialog after getting all products
        // updating UI from Background Thread



         /**
          * Updating parsed JSON data into ListView
          * */
         StableArrayAdapter adapter = new StableArrayAdapter(getActivity(), viewContent);
         // updating listview
         lv.setAdapter(adapter);
         adapter.notifyDataSetChanged();




    }








    private class StableArrayAdapter extends ArrayAdapter<String> {

        private final Context context;
        private List<String> viewString;
        private ImageView image;
        private TextView addToCalendarButton;
        private TextView eventTitle;
        private ImageView eventImage;
        private TextView likesTV;
        private TextView planToAttendTV;

        public StableArrayAdapter(Context context, List<String> strings) {
            super(context, R.layout.post_layout, strings);
            this.context = context;
            this.viewString = strings;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View postLayout = inflater.inflate(R.layout.post_layout, parent, false);

            TextView unameTV = (TextView)postLayout.findViewById(R.id.postUnameTv);
            unameTV.setText(viewString.get(0));

            image = (ImageView)postLayout.findViewById(R.id.postProfPic);
            DisplayImageOptions options = initiateDisplayImageOptions();
            ImageLoader imageloader = ImageLoader.getInstance();
            initImageLoader(getActivity());
            imageloader.displayImage(viewString.get(1), image, options);


            addToCalendarButton = (TextView)postLayout.findViewById(R.id.addToCalendarButton);
            addToCalendarButton.setText(viewString.get(2));

            eventTitle = (TextView)postLayout.findViewById(R.id.postTitleTV);
            eventTitle.setText(viewString.get(3));

            eventImage = (ImageView)postLayout.findViewById(R.id.eventImage);
            imageloader.displayImage(viewString.get(4), eventImage, options);


            likesTV = (TextView)postLayout.findViewById(R.id.likesTV);
            likesTV.setText(""+viewContent.get(5));

            planToAttendTV = (TextView)postLayout.findViewById(R.id.planToAttendTV);
            planToAttendTV.setText(viewString.get(6));

            Log.d("Adapter", ""+viewString.get(6));



            return postLayout;
        }


        @Override
        public int getCount()
        {
            Log.d("Adapter", ""+viewString.size());
            return viewString.size();
        }

        @Override
        public String getItem(int position) {
            return viewString.get(position);
        }

    }

}











public DisplayImageOptions initiateDisplayImageOptions()
{
    DisplayImageOptions options = new DisplayImageOptions.Builder()
            .cacheInMemory(true)
            .cacheOnDisc(true)
            .bitmapConfig(Bitmap.Config.RGB_565)
            .build();

    return options;
}


protected void initImageLoader(Context context) {
    // This configuration tuning is custom. You can tune every option, you may tune some of them,
    // or you can create default configuration by
    //  ImageLoaderConfiguration.createDefault(this);
    // method.
    ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(context)
            .threadPriority(Thread.NORM_PRIORITY - 2)
            .denyCacheImageMultipleSizesInMemory()
            .diskCacheFileNameGenerator(new Md5FileNameGenerator())
            .tasksProcessingOrder(QueueProcessingType.LIFO)
            .writeDebugLogs() // Remove for release app
            .build();

    // Initialize ImageLoader with configuration.
    ImageLoader.getInstance().init(config);
}

public String getMonth(int mon)
{
    String month;

    if(mon == 1)
    {
        month = "January";
    }
    else if (mon == 2)
    {
        month = "February";
    }
    else if (mon == 3)
    {
        month = "March";
    }
    else if (mon == 4)
    {
        month = "April";
    }
    else if (mon == 5)
    {
        month = "May";
    }
    else if (mon == 6)
    {
        month = "June";
    }
    else if (mon == 7)
    {
        month = "July";
    }
    else if (mon == 8)
    {
        month = "August";
    }
    else if (mon == 9)
    {
        month = "September";
    }
    else if (mon == 10)
    {
        month = "October";
    }
    else if (mon == 11)
    {
        month = "November";
    }
    else
    {
        month = "December";
    }


    return month;
}

}

Answer 1

尝试更改此行

// Get listview
lv = (ListView) view.findViewById(R.id.listView);

到

lv = (ListView) getActivity().findViewById(R.id.listView);

见ListFragment Not Rendering and getView() in Adapter Not Being Called

Answer 2

我不确定你是否需要

 getActivity().runOnUiThread(new Runnable() {
            public void run() {

}

在 onPostExecute() 内部。它会自动在 UI 线程上执行所有操作。请删除它并查看。

Answer 3

致所有可能面临类似问题的人。从未调用过getView() 的原因是因为在我的片段的onCreateView() 中，当我返回视图时，我在最后膨胀了一个新布局。我的问题是我正在修改膨胀布局中的视图，然后我正在返回一个新视图，因此 getView 没有时间被调用，即使它这样做了，它也不会显示任何结果，因为我正在膨胀一个全新的布局。为了解决这个问题，我删除了 return (RelativeLayout)inflater.inflate(R.layout.main_feed_layout, container, false);，而是放了return view;。这立即解决了我的问题。

Answer 4

您的 doInBackground() 正在填充一个名为“viewContent”的静态变量。由于 doInBackground() 发生在后台线程中，并且当您在运行在不同线程中的 onPostExecute() 上使用它时，它会因为 Thread visibility issue 而失败，在其他换句话说，一个线程更改的变量对另一个线程不可见，除非您在同步区域中执行此操作。在同步区域中执行此操作将使您的代码正常工作，但这不是 Android 使用 AsyncTask 的方式。

您应该做的是：删除使您的 doInBackground() 返回此列表的副本，并且在您的 onPostExecute() 上，您将收到此列表作为参数，然后您可以将其绕过到适配器.忘记这个 static List viewContent = new ArrayList(); 除非你想缓存结果，但要小心使用它。

解决方案示例如下：

class LoadAllProducts extends AsyncTask<String, String, List<String>> {

  protected List<String> doInBackground(String... args) {
    List<String> allData = ....
    return allData;
  }


  protected void onPostExecute(List<String> allData) {
    Log.d("Loading Events: ", "Events Loaded");

     StableArrayAdapter adapter = new StableArrayAdapter(getActivity(), allData);
     // updating listview
     lv.setAdapter(adapter);
     adapter.notifyDataSetChanged();
   }

}

---

适配器上的其他相邻问题：

您的适配器有一个字符串列表..好的。但是适配器的设计目的是为列表的每个项目调用 getView()。在您的获取视图中，您调用列表中的所有位置，这违背了目的。

在你的 getView() 中你应该调用：

 String currentItem = getItem(position);
 // note that 'position' is one of the given parameters for the getView().

请阅读getView() api以更深入地了解每个参数。