无法看到 ListView

Question

我没有在 listView 中看到任何数据我从网络服务获取所有数据，但我没有在 ListView 中看到它。我得到了流程，我知道它永远不会进入 getView() 方法请向我解释该代码中的错误并向我推荐最佳代码。

public class WeatherReport extends Activity {

    ListView listView;
    GPS_Location gpsObj;
    BaseAdapter aAdapter;
    double Latitude, Longitude;
    Bitmap image;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.weather_report);
        listView = (ListView) findViewById(R.id.listView);
        gpsObj = new GPS_Location(this);
        Latitude = gpsObj.getLatitude();
        Longitude = gpsObj.getLongitude();
        System.out.println("Inside onCreate() ");
        String Url = "http://api.openweathermap.org/data/2.5/forecast/daily?lat=" + Latitude + "&lon=" + Longitude + "&cnt=14&mode=json";
        new getJSON().execute(Url);
        //  listView.setAdapter(new BAdapter(this));
    }

    private class getJSON extends AsyncTask<String, String, String> {
        String cityName;
        String Latitude, Longitude;
        ArrayList<SingleRow> list;
        ArrayList<String> humidity;
        ArrayList<String> speed;
        ArrayList<String> weather;
        ArrayList<String> tempMin;
        ArrayList<String> tempMax;
        ArrayList<String> description;
        ArrayList<Bitmap> icon;

        @Override
        protected String doInBackground(String... params) {
            String Url = params[0];
            humidity = new ArrayList<String>();
            speed = new ArrayList<String>();
            weather = new ArrayList<String>();
            tempMin = new ArrayList<String>();
            tempMax = new ArrayList<String>();
            icon = new ArrayList<Bitmap>();
            description = new ArrayList<String>();
            String data;
            try {
                HttpClient hClient = new DefaultHttpClient();
                HttpGet hGet = new HttpGet(Url);
                ResponseHandler<String> rHandler = new BasicResponseHandler();
                data = hClient.execute(hGet, rHandler);
                System.out.println("Inside doInBackground  data " + data);
                JSONObject jObj = new JSONObject(data);
                System.out.println("Inside Background jObj " + jObj);
                JSONObject jsonObject = jObj.getJSONObject("city");
                cityName = jsonObject.getString("name");
                JSONObject jObjCoOrd = jsonObject.getJSONObject("coord");
                Latitude = jObjCoOrd.getString("lat");
                System.out.println("Inside Latitude " + Latitude);
                Longitude = jObjCoOrd.getString("lon");
                System.out.println("Inside Longitude " + Longitude);

                JSONArray jsonArray = jObj.getJSONArray("list");
                System.out.println("Inside jsonObjList " + jsonArray);
                for (int i = 0; i < jsonArray.length(); i++) {
                    JSONObject object = jsonArray.getJSONObject(i);

                    String humidityString = object.getString("humidity");
                    humidity.add(humidityString);
                    String speedString = object.getString("speed");
                    System.out.println("Inside speedString " + speedString);
                    speed.add(speedString);

                    JSONArray weatherArray = object.getJSONArray("weather");
                    JSONObject weatherObj = weatherArray.getJSONObject(0);

                    String iconString = weatherObj.getString("icon");
                    final String iconURL = "http://openweathermap.org/img/w/" + iconString + ".png";
                    image = getImage(iconURL);
                    icon.add(image);
                    System.out.println("Inside icon " + icon);
                    String descriptionString = weatherObj.getString("description");
                    System.out.println("Inside descriptionString " + descriptionString);
                    description.add(descriptionString);

                    JSONObject tempObj = object.getJSONObject("temp");

                    String minTemp = tempObj.getString("min");
                    System.out.println("Inside minTemp " + minTemp);
                    tempMin.add(minTemp);

                    String maxTemp = tempObj.getString("max");
                    System.out.println("Inside maxTemp " + maxTemp);
                    tempMax.add(maxTemp);
                }

                aAdapter = new ListViewCustomAdapter(WeatherReport.this,
                        Latitude, Longitude, cityName, humidity, speed, icon, description, tempMin, tempMax);
                listView.setAdapter(aAdapter);

            } catch (Exception e) {
                Log.w("Error", e.getMessage());
            }
            return null;
        }

        private Bitmap getImage(String iconURL) {
            InputStream in = null;
            Bitmap bmp = null;
            int responseCode = -1;
            try {

                URL url = new URL(iconURL);//"http://192.xx.xx.xx/mypath/img1.jpg
                HttpURLConnection con = (HttpURLConnection) url.openConnection();
                con.setDoInput(true);
                con.connect();
                responseCode = con.getResponseCode();
                if (responseCode == HttpURLConnection.HTTP_OK) {
                    //download
                    in = con.getInputStream();
                    bmp = BitmapFactory.decodeStream(in);
                    in.close();
                }

            } catch (Exception ex) {
                Log.e("Exception", ex.toString());
            }


            return bmp;
        }

        private class ListViewCustomAdapter extends BaseAdapter {
            Context context;
            public LayoutInflater inflater;
            String Latitude, Longitude, cityName;
            String[] Humidity, Speed, Description1, minTemp, maxTemp ;
            ArrayList<Bitmap> bitmap;


            public ListViewCustomAdapter(Context context, String latitude, String longitude, String cityName, ArrayList<String> humidity, ArrayList<String> speed, ArrayList<Bitmap> image, ArrayList<String> description, ArrayList<String> tempMin, ArrayList<String> tempMax) {
                this.context = context;
                this.Latitude = latitude;
                this.Longitude = longitude;
                this.cityName = cityName;
                this.bitmap = icon;
                this.Humidity = humidity.toArray(new String[humidity.size()]);
                this.Speed = speed.toArray(new String[speed.size()]);
                this.Description1 = description.toArray(new String[description.size()]);
                this.minTemp = tempMin.toArray(new String[tempMin.size()]);
                this.maxTemp = tempMax.toArray(new String[tempMax.size()]);
                this.inflater = (LayoutInflater) context
                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                System.out.println("Inside ListViewCustomAdapter ");
            }

            @Override
            public int getCount() {
                return 0;
            }

            @Override
            public Object getItem(int i) {
                return i;
            }

            @Override
            public long getItemId(int i) {
                return i;
            }

            private class Holder {
                TextView City, MinTemp, MaxTemp, Description, Speed, Latitude, Longitude, Humidity;
                ImageView cloud;
            }

            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                Holder holder= null;
                View view = convertView;
                System.out.println("Inside getView");
                if(view== null){
                    System.out.println("Inside if getView");
                    holder = new Holder();
                    convertView = inflater.inflate(R.layout.weather_report_single_item, null);
                    holder.cloud = (ImageView) findViewById(R.id.cloud);
                    holder.City = (TextView) findViewById(R.id.cityName);
                    holder.MinTemp= (TextView) findViewById(R.id.minTemp);
                    holder.MaxTemp= (TextView) findViewById(R.id.maxTemp);
                    holder.Description=(TextView) findViewById(R.id.weather);
                    holder.Speed =(TextView) findViewById(R.id.speed);
                    holder.Latitude = (TextView) findViewById(R.id.latitude);
                    holder.Longitude= (TextView) findViewById(R.id.longitude);
                    holder.Humidity= (TextView) findViewById(R.id.humidity);

                    convertView.setTag(holder);
                }else{
                    System.out.println("Inside else getView");
                    holder = (Holder) convertView.getTag();
                    holder.City.setText(cityName);
                    holder.Latitude.setText(Latitude);
                    holder.Longitude.setText(Longitude);
                    holder.MaxTemp.setText(maxTemp[position]);
                    holder.MinTemp.setText(minTemp[position]);
                    holder.Speed.setText(Speed[position]);
                    holder.Description.setText(Description1[position]);
                    holder.cloud.setImageBitmap(bitmap.get(position));
                }

                return convertView;
            }
        }
    }
}

class SingleRow {
    String minTemp, maxTemp, speed, humidity;
    Bitmap img;

    SingleRow(String minTemp, String maxTemp, String speed, String humidity, Bitmap img) {

        this.maxTemp = maxTemp;
        this.minTemp = minTemp;
        this.speed = speed;
        this.humidity = humidity;
        this.img = img;
    }

}

Answer 1

你好，基本适配器中的 getCount() returns 0 将其更改为你拥有的数据总大小

 @Override
        public int getCount() {
            return Humidity.length;
        }

也改变

  aAdapter = new ListViewCustomAdapter(WeatherReport.this,
                    Latitude, Longitude, cityName, humidity, speed, icon, description, tempMin, tempMax);
            listView.setAdapter(aAdapter);

从异步任务中的 doInBackground 到 onPostExecute 方法 Class

  @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
aAdapter = new ListViewCustomAdapter(WeatherReport.this,
                    Latitude, Longitude, cityName, humidity, speed, icon, description, tempMin, tempMax);
            listView.setAdapter(aAdapter);
    }

完整代码如下所示

public class WeatherReport extends Activity {

ListView listView;
GPS_Location gpsObj;
BaseAdapter aAdapter;
double Latitude, Longitude;
Bitmap image;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.weather_report);
    listView = (ListView) findViewById(R.id.listView);
    gpsObj = new GPS_Location(this);
    Latitude = gpsObj.getLatitude();
    Longitude = gpsObj.getLongitude();
    System.out.println("Inside onCreate() ");
    String Url = "http://api.openweathermap.org/data/2.5/forecast/daily?lat=" + Latitude + "&lon=" + Longitude + "&cnt=14&mode=json";
    new getJSON().execute(Url);
    //  listView.setAdapter(new BAdapter(this));
}

private class getJSON extends AsyncTask<String, String, String> {
    String cityName;
    String Latitude, Longitude;
    ArrayList<SingleRow> list;
    ArrayList<String> humidity;
    ArrayList<String> speed;
    ArrayList<String> weather;
    ArrayList<String> tempMin;
    ArrayList<String> tempMax;
    ArrayList<String> description;
    ArrayList<Bitmap> icon;

    @Override
    protected String doInBackground(String... params) {
        String Url = params[0];
        humidity = new ArrayList<String>();
        speed = new ArrayList<String>();
        weather = new ArrayList<String>();
        tempMin = new ArrayList<String>();
        tempMax = new ArrayList<String>();
        icon = new ArrayList<Bitmap>();
        description = new ArrayList<String>();
        String data;
        try {
            HttpClient hClient = new DefaultHttpClient();
            HttpGet hGet = new HttpGet(Url);
            ResponseHandler<String> rHandler = new BasicResponseHandler();
            data = hClient.execute(hGet, rHandler);
            System.out.println("Inside doInBackground  data " + data);
            JSONObject jObj = new JSONObject(data);
            System.out.println("Inside Background jObj " + jObj);
            JSONObject jsonObject = jObj.getJSONObject("city");
            cityName = jsonObject.getString("name");
            JSONObject jObjCoOrd = jsonObject.getJSONObject("coord");
            Latitude = jObjCoOrd.getString("lat");
            System.out.println("Inside Latitude " + Latitude);
            Longitude = jObjCoOrd.getString("lon");
            System.out.println("Inside Longitude " + Longitude);

            JSONArray jsonArray = jObj.getJSONArray("list");
            System.out.println("Inside jsonObjList " + jsonArray);
            for (int i = 0; i < jsonArray.length(); i++) {
                JSONObject object = jsonArray.getJSONObject(i);

                String humidityString = object.getString("humidity");
                humidity.add(humidityString);
                String speedString = object.getString("speed");
                System.out.println("Inside speedString " + speedString);
                speed.add(speedString);

                JSONArray weatherArray = object.getJSONArray("weather");
                JSONObject weatherObj = weatherArray.getJSONObject(0);

                String iconString = weatherObj.getString("icon");
                final String iconURL = "http://openweathermap.org/img/w/" + iconString + ".png";
                image = getImage(iconURL);
                icon.add(image);
                System.out.println("Inside icon " + icon);
                String descriptionString = weatherObj.getString("description");
                System.out.println("Inside descriptionString " + descriptionString);
                description.add(descriptionString);

                JSONObject tempObj = object.getJSONObject("temp");

                String minTemp = tempObj.getString("min");
                System.out.println("Inside minTemp " + minTemp);
                tempMin.add(minTemp);

                String maxTemp = tempObj.getString("max");
                System.out.println("Inside maxTemp " + maxTemp);
                tempMax.add(maxTemp);
            }

           //Removed Setting Adaptor from do in background to onPostExecute

        } catch (Exception e) {
            Log.w("Error", e.getMessage());
        }
        return null;
    }


    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);

        //The Last Step in Async Task Do set adaptor here

        aAdapter = new ListViewCustomAdapter(WeatherReport.this,
                Latitude, Longitude, cityName, humidity, speed, icon, description, tempMin, tempMax);
        listView.setAdapter(aAdapter);
    }
}

    private Bitmap getImage(String iconURL) {
        InputStream in = null;
        Bitmap bmp = null;
        int responseCode = -1;
        try {

            URL url = new URL(iconURL);//"http://192.xx.xx.xx/mypath/img1.jpg
            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            con.setDoInput(true);
            con.connect();
            responseCode = con.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                //download
                in = con.getInputStream();
                bmp = BitmapFactory.decodeStream(in);
                in.close();
            }

        } catch (Exception ex) {
            Log.e("Exception", ex.toString());
        }


        return bmp;
    }

    private class ListViewCustomAdapter extends BaseAdapter {
        Context context;
        public LayoutInflater inflater;
        String Latitude, Longitude, cityName;
        String[] Humidity, Speed, Description1, minTemp, maxTemp ;
        ArrayList<Bitmap> bitmap;


        public ListViewCustomAdapter(Context context, String latitude, String longitude, String cityName, ArrayList<String> humidity, ArrayList<String> speed, ArrayList<Bitmap> image, ArrayList<String> description, ArrayList<String> tempMin, ArrayList<String> tempMax) {
            this.context = context;
            this.Latitude = latitude;
            this.Longitude = longitude;
            this.cityName = cityName;
            this.bitmap = icon;
            this.Humidity = humidity.toArray(new String[humidity.size()]);
            this.Speed = speed.toArray(new String[speed.size()]);
            this.Description1 = description.toArray(new String[description.size()]);
            this.minTemp = tempMin.toArray(new String[tempMin.size()]);
            this.maxTemp = tempMax.toArray(new String[tempMax.size()]);
            this.inflater = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            System.out.println("Inside ListViewCustomAdapter ");
        }

        @Override
        public int getCount() {

            //Prev you have been returning 0 its changed from 0 to Humidity.length so that base adaptor show the result as listview

            return Humidity.length;
        }

        @Override
        public Object getItem(int i) {
            return i;
        }

        @Override
        public long getItemId(int i) {
            return i;
        }

        private class Holder {
            TextView City, MinTemp, MaxTemp, Description, Speed, Latitude, Longitude, Humidity;
            ImageView cloud;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            Holder holder= null;
            View view = convertView;
            System.out.println("Inside getView");
            if(view== null){
                System.out.println("Inside if getView");
                holder = new Holder();
                convertView = inflater.inflate(R.layout.weather_report_single_item, null);
                holder.cloud = (ImageView) findViewById(R.id.cloud);
                holder.City = (TextView) findViewById(R.id.cityName);
                holder.MinTemp= (TextView) findViewById(R.id.minTemp);
                holder.MaxTemp= (TextView) findViewById(R.id.maxTemp);
                holder.Description=(TextView) findViewById(R.id.weather);
                holder.Speed =(TextView) findViewById(R.id.speed);
                holder.Latitude = (TextView) findViewById(R.id.latitude);
                holder.Longitude= (TextView) findViewById(R.id.longitude);
                holder.Humidity= (TextView) findViewById(R.id.humidity);

                convertView.setTag(holder);
            }else{
                System.out.println("Inside else getView");
                holder = (Holder) convertView.getTag();
                holder.City.setText(cityName);
                holder.Latitude.setText(Latitude);
                holder.Longitude.setText(Longitude);
                holder.MaxTemp.setText(maxTemp[position]);
                holder.MinTemp.setText(minTemp[position]);
                holder.Speed.setText(Speed[position]);
                holder.Description.setText(Description1[position]);
                holder.cloud.setImageBitmap(bitmap.get(position));
            }

            return convertView;
        }
    }



class SingleRow {
    String minTemp, maxTemp, speed, humidity;
    Bitmap img;

    SingleRow(String minTemp, String maxTemp, String speed, String humidity, Bitmap img) {

        this.maxTemp = maxTemp;
        this.minTemp = minTemp;
        this.speed = speed;
        this.humidity = humidity;
        this.img = img;
    }

}

}

Answer 2

给出将要显示的记录的长度..在获取计数方法中给出array/collection长度

检查适配器的以下代码。在你犯错的地方也添加了评论和建议

设置listview adapter和all in async task onPostExecute方法。

已编辑 检查我用 #### SUGGESTION

标记的建议

public class WeatherReport extends Activity {

    ListView listView;
    // GPS_Location gpsObj;
    // BaseAdapter aAdapter;
    double Latitude, Longitude;
    Bitmap image;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.listview_);
        listView = (ListView) findViewById(R.id.listdata);
        // gpsObj = new GPS_Location(this);
        /*
         * For testing i gve static lat long values as i dnt hve your
         * GPS_Location class
         */
        Latitude = 23;
        Longitude = 73;
        System.out.println("Inside onCreate() ");
        String Url = "http://api.openweathermap.org/data/2.5/forecast/daily?lat="
                + Latitude + "&lon=" + Longitude + "&cnt=14&mode=json";
        new getJSON().execute(Url);
        // listView.setAdapter(new BAdapter(this));
    }

    private class getJSON extends AsyncTask<String, String, String> {
        String cityName;
        String Latitude, Longitude;
        ArrayList<SingleRow> list;
        ArrayList<String> humidity;
        ArrayList<String> speed;
        ArrayList<String> weather;
        ArrayList<String> tempMin;
        ArrayList<String> tempMax;
        ArrayList<String> description;
        ArrayList<String> icon;

        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            listView.setAdapter(new ListViewCustomAdapter(WeatherReport.this,
                    Latitude, Longitude, cityName, humidity, speed, icon,
                    description, tempMin, tempMax));
        }

        @Override
        protected String doInBackground(String... params) {
            String Url = params[0];
            humidity = new ArrayList<String>();
            speed = new ArrayList<String>();
            weather = new ArrayList<String>();
            tempMin = new ArrayList<String>();
            tempMax = new ArrayList<String>();
            icon = new ArrayList<String>();
            description = new ArrayList<String>();
            String data;
            try {
                HttpClient hClient = new DefaultHttpClient();
                HttpGet hGet = new HttpGet(Url);
                ResponseHandler<String> rHandler = new BasicResponseHandler();
                data = hClient.execute(hGet, rHandler);
                System.out.println("Inside doInBackground  data " + data);
                JSONObject jObj = new JSONObject(data);
                System.out.println("Inside Background jObj " + jObj);
                JSONObject jsonObject = jObj.getJSONObject("city");
                cityName = jsonObject.getString("name");
                JSONObject jObjCoOrd = jsonObject.getJSONObject("coord");
                Latitude = jObjCoOrd.getString("lat");
                System.out.println("Inside Latitude " + Latitude);
                Longitude = jObjCoOrd.getString("lon");
                System.out.println("Inside Longitude " + Longitude);

                JSONArray jsonArray = jObj.getJSONArray("list");
                System.out.println("Inside jsonObjList " + jsonArray);
                for (int i = 0; i < jsonArray.length(); i++) {
                    JSONObject object = jsonArray.getJSONObject(i);

                    String humidityString = object.getString("humidity");
                    humidity.add(humidityString);
                    String speedString = object.getString("speed");
                    System.out.println("Inside speedString " + speedString);
                    speed.add(speedString);

                    JSONArray weatherArray = object.getJSONArray("weather");
                    JSONObject weatherObj = weatherArray.getJSONObject(0);

                    String iconString = weatherObj.getString("icon");
                    final String iconURL = "http://openweathermap.org/img/w/"
                            + iconString + ".png";
                    // #### SUGGESTION

                    // Do not Download images or files like this
                    // to display images use imageloader lazy loading library is
                    // available

                    // https://github.com/nostra13/Android-Universal-Image-Loader/tree/master/sample

                    // Comment image downloading related below line and once
                    // check

                    // image = getImage(iconURL);
                    // icon.add(image);

                    // here other change i hve made is converty bitmap array
                    // list to String which will hve images url not bitmap
                    icon.add(iconURL);
                    System.out.println("Inside icon " + icon);
                    String descriptionString = weatherObj
                            .getString("description");
                    System.out.println("Inside descriptionString "
                            + descriptionString);
                    description.add(descriptionString);

                    JSONObject tempObj = object.getJSONObject("temp");

                    String minTemp = tempObj.getString("min");
                    System.out.println("Inside minTemp " + minTemp);
                    tempMin.add(minTemp);

                    String maxTemp = tempObj.getString("max");
                    System.out.println("Inside maxTemp " + maxTemp);
                    tempMax.add(maxTemp);
                }

                // If u do any ui related changes here below exception will come
                // so need to move ui changes in onPostExecute

                // android.view.ViewRootImpl$CalledFromWrongThreadException:
                // Only the original thread that created a view hierarchy can
                // touch its views.

                // listView.setAdapter(new ListViewCustomAdapter(
                // WeatherReport.this, Latitude, Longitude, cityName,
                // humidity, speed, icon, description, tempMin, tempMax));

            } catch (Exception e) {
                Log.w("Error", e.getMessage());
            }
            return null;
        }

        private Bitmap getImage(String iconURL) {
            InputStream in = null;
            Bitmap bmp = null;
            int responseCode = -1;
            try {

                URL url = new URL(iconURL);// "http://192.xx.xx.xx/mypath/img1.jpg
                HttpURLConnection con = (HttpURLConnection) url
                        .openConnection();
                con.setDoInput(true);
                con.connect();
                responseCode = con.getResponseCode();
                if (responseCode == HttpURLConnection.HTTP_OK) {
                    // download
                    in = con.getInputStream();
                    bmp = BitmapFactory.decodeStream(in);
                    in.close();
                }

            } catch (Exception ex) {
                Log.e("Exception", ex.toString());
            }

            return bmp;
        }

        private class ListViewCustomAdapter extends BaseAdapter {
            Context context;
            public LayoutInflater inflater;
            String Latitude, Longitude, cityName;
            String[] Humidity, Speed, Description1, minTemp, maxTemp;
            ArrayList<String> bitmap;
            int totalDisplayDatasize = 0;

            public ListViewCustomAdapter(Context context, String latitude,
                    String longitude, String cityName,
                    ArrayList<String> humidity, ArrayList<String> speed,
                    ArrayList<String> image, ArrayList<String> description,
                    ArrayList<String> tempMin, ArrayList<String> tempMax) {
                this.context = context;
                this.Latitude = latitude;
                this.Longitude = longitude;
                this.cityName = cityName;
                this.bitmap = icon;
                this.Humidity = humidity.toArray(new String[humidity.size()]);
                this.Speed = speed.toArray(new String[speed.size()]);
                this.Description1 = description.toArray(new String[description
                        .size()]);
                this.minTemp = tempMin.toArray(new String[tempMin.size()]);
                this.maxTemp = tempMax.toArray(new String[tempMax.size()]);
                // /suggestion : No need to create LayoutInflater instance in
                // constructor
                // this.inflater = (LayoutInflater) context
                // .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

                /**
                 * set total data length for count
                 * */
                if (this.Humidity != null)
                    totalDisplayDatasize = this.Humidity.length;
                System.out.println("Inside ListViewCustomAdapter ");
            }

            @Override
            public int getCount() {
                // this could be one of the reason for not showing listview.set
                // total data length for count
                return totalDisplayDatasize;
            }

            @Override
            public Object getItem(int i) {
                return i;
            }

            @Override
            public long getItemId(int i) {
                return i;
            }

            private class Holder {
                TextView City, MinTemp, MaxTemp, Description, Speed, Latitude,
                        Longitude, Humidity;
                ImageView cloud;
            }

            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                Holder holder = null;
                View view = convertView;
                System.out.println("Inside getView");
                if (view == null) {
                    System.out.println("Inside if getView");
                    holder = new Holder();
                    // / No need to create LayoutInflater instance in
                    // constructor

                    convertView = LayoutInflater.from(this.context).inflate(
                            R.layout.list_row_data, null);
                    // Create instance from convertview.findviewbyid instead of
                    // directly using findViewById
                    // holder.cloud = (ImageView) convertView
                    // .findViewById(R.id.cloud);
                    // holder.City = (TextView) convertView
                    // .findViewById(R.id.cityName);
                    holder.MinTemp = (TextView) convertView
                            .findViewById(R.id.minTemp);
                    holder.MaxTemp = (TextView) convertView
                            .findViewById(R.id.maxTemp);
                    holder.Description = (TextView) convertView
                            .findViewById(R.id.weather);
                    holder.Speed = (TextView) convertView
                            .findViewById(R.id.speed);
                    holder.Latitude = (TextView) convertView
                            .findViewById(R.id.latitude);
                    holder.Longitude = (TextView) convertView
                            .findViewById(R.id.longitude);

                    convertView.setTag(holder);
                } else {
                    System.out.println("Inside else getView");
                    holder = (Holder) convertView.getTag();

                }// set values here for each row

                // holder.City.setText(cityName);
                holder.Latitude.setText("Lat : " + Latitude);
                holder.Longitude.setText("Long : " + Longitude);
                holder.MaxTemp.setText("maxTemp : " + maxTemp[position]);
                holder.MinTemp.setText("minTemp : " + minTemp[position]);
                holder.Speed.setText("Speed : " + Speed[position]);
                holder.Description.setText("Description : "
                        + Description1[position]);
                // #### SUGGESTION

                // TO display image use ImageLoader which will download image in
                // background and will display
                // https://github.com/nostra13/Android-Universal-Image-Loader/tree/master/sample

                // holder.cloud.setImageBitmap(bitmap.get(position));
                return convertView;
            }
        }
    }
}

class SingleRow {
    String minTemp, maxTemp, speed, humidity;
    Bitmap img;

    SingleRow(String minTemp, String maxTemp, String speed, String humidity,
            Bitmap img) {

        this.maxTemp = maxTemp;
        this.minTemp = minTemp;
        this.speed = speed;
        this.humidity = humidity;
        this.img = img;
    }

}

list_row_data.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_margin="5dp"
    android:layout_height="wrap_content"
    android:background="#ffffff"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/speed"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#ffff8800" />

    <TextView
        android:id="@+id/weather"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#ffff8800" />

    <TextView
        android:id="@+id/latitude"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#ffff8800" />

    <TextView
        android:id="@+id/longitude"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#ffff8800" />

    <TextView
        android:id="@+id/minTemp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#ffff8800" />

    <TextView
        android:id="@+id/maxTemp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#ffff8800" />

</LinearLayout>

listview_.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <ListView
        android:id="@+id/listdata"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />

</LinearLayout>

Answer 3

编辑

首先写

      @Override
        public int getCount() {
            return Humidity.length();;
        }

而不是

       @Override
        public int getCount() {
            return 0;
        }

并且您在 getview() 的 else 部分中将值设置为行视图，在 if else

之后设置值

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            Holder holder= null;
            View view = convertView;
            System.out.println("Inside getView");
            if(view== null){
                System.out.println("Inside if getView");
                holder = new Holder();
                convertView = inflater.inflate(R.layout.weather_report_single_item, null);
                holder.cloud = (ImageView) findViewById(R.id.cloud);
               convertView.setTag(holder);

            }else{
                System.out.println("Inside else getView");
                holder = (Holder) convertView.getTag();

            }

                holder.City.setText(cityName);
                holder.Latitude.setText(Latitude);
                holder.Longitude.setText(Longitude);
                holder.MaxTemp.setText(maxTemp[position]);
                holder.MinTemp.setText(minTemp[position]);
                holder.Speed.setText(Speed[position]);
                holder.Description.setText(Description1[position]);
                holder.cloud.setImageBitmap(bitmap.get(position));

            return convertView;
        }

Answer 4

在 getJSON class.

的 onPostExecute 方法中创建并设置 ListView 的 adapter

getCount() - 此适配器表示的数据集中有多少项。您正在返回 0 意味着您将适配器的数据设置为 0 因此不会扩充任何行。

在适配器中将所有这些字符串数组更改为 ArrayList<String> 除了您需要更改构造函数，getCount 和 getView 部分

声明

ArrayList<Bitmap> bitmap, Humidity, Speed, Description1, minTemp, maxTemp;

构造函数

public ListViewCustomAdapter(Context context, String latitude, String longitude, String cityName, ArrayList<String> humidity, ArrayList<String> speed, ArrayList<Bitmap> image, ArrayList<String> description, ArrayList<String> tempMin, ArrayList<String> tempMax) {
    this.context = context;
    this.Latitude = latitude;
    this.Longitude = longitude;
    this.cityName = cityName;
    this.bitmap = icon;
    this.Humidity = humidity;
    this.Speed = speed;
    this.Description1 = description;
    this.minTemp = tempMin;
    this.maxTemp = tempMax;
    this.inflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    System.out.println("Inside ListViewCustomAdapter ");
}

getCount 部分

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

获取视图部分

@Override
public View getView(int position, View convertView, ViewGroup parent) {
   Holder holder= null;
   View view = convertView;
   System.out.println("Inside getView");
   if(view== null){
        System.out.println("Inside if getView");
        holder = new Holder();
        convertView = inflater.inflate(R.layout.weather_report_single_item, parent, false);
        holder.cloud = (ImageView) findViewById(R.id.cloud);
        holder.City = (TextView) findViewById(R.id.cityName);
        holder.MinTemp= (TextView) findViewById(R.id.minTemp);
        holder.MaxTemp= (TextView) findViewById(R.id.maxTemp);
        holder.Description=(TextView) findViewById(R.id.weather);
        holder.Speed =(TextView) findViewById(R.id.speed);
        holder.Latitude = (TextView) findViewById(R.id.latitude);
        holder.Longitude= (TextView) findViewById(R.id.longitude);
        holder.Humidity= (TextView) findViewById(R.id.humidity);

        convertView.setTag(holder);
   }else{
      System.out.println("Inside else getView");
      holder = (Holder) convertView.getTag();
   }
   holder.City.setText(cityName);
   holder.Latitude.setText(Latitude);
   holder.Longitude.setText(Longitude);
   holder.MaxTemp.setText(maxTemp.get(position));
   holder.MinTemp.setText(minTemp.get(position));
   holder.Speed.setText(Speed.get(position));
   holder.Description.setText(Description1.get(position));
   holder.cloud.setImageBitmap(bitmap.get(position));
   return convertView;
 }

无法看到 ListView

Not able to see ListView

android

listview

android-arrayadapter