Question

我正在使用Json数据创建列表视图。我正在填充一些图像，文本字段和一个按钮。当用户点击按钮按钮时，标题会发生变化。

问题是如果按钮被修改并且用户滚动，列表视图按钮将重置为第一状态。请查看此视频，最好先解释一下：https://www.youtube.com/watch?v=57ZraP7ED2E&feature=youtu.be

适配器

public class FilmRequestAdapter extends ArrayAdapter<FilmRequest>{
    Context context;
    List<FilmRequest> data;

    public FilmRequestAdapter(Context context, int resource, List<FilmRequest> objects) {
        super(context, resource, objects);
        // TODO Auto-generated constructor stub

        this.context=context;
        this.data=objects;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row=convertView;

        if (row==null) {
            LayoutInflater inflater=((Activity)context).getLayoutInflater();
            row=inflater.inflate(R.layout.film_request_list,null);
        }

        ((TextView)row.findViewById(R.id.FilmRequestFilmTitle)).setText(((FilmRequest)data.get(position)).title);
        ((TextView)row.findViewById(R.id.FilmRequestRating)).setText("Imdb Puanı : "+((FilmRequest)data.get(position)).rating);
        ((TextView)row.findViewById(R.id.FilmRequestOrder)).setText("Sıra : "+((FilmRequest)data.get(position)).order);
        ((TextView)row.findViewById(R.id.FilmRequestVoteCount)).setText("Oya adeti : "+((FilmRequest)data.get(position)).voteCount);

        Button button=(Button)row.findViewById(R.id.FilmRequestActionButton);
        String status=((FilmRequest)data.get(position)).status;
        boolean requested=((FilmRequest)data.get(position)).requested;
        boolean voted=((FilmRequest)data.get(position)).voted;
        if (status.equalsIgnoreCase("A") || status.equalsIgnoreCase("")) {

            if (requested) {
                if (voted) {
                    button.setText("Oylanmış");
                    button.setEnabled(false);
                }else {
                    button.setText("+ Oyla");
                    button.setEnabled(true);
                    button.setTag(R.string.film_request_action, "VOTEABLE");
                    button.setTag(R.string.film_request_id,((FilmRequest)data.get(position)).id);
                }
            } else {
                button.setText("Filmi İste");
                button.setEnabled(true);
                button.setTag(R.string.film_request_action, "REQUESTABLE");
                button.setTag(R.string.film_request_id,((FilmRequest)data.get(position)).imdbId);               
            }

        } else {
            button.setText("Eklenmiş");
            button.setEnabled(false);
        }

        button.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                FilmRequestActivity.ButtonClickFunction(context,(Button)v);
            }
        });

        ((ImageView)row.findViewById(R.id.FilmRequestPoster)).setImageBitmap(((FilmRequest)data.get(position)).bm);

        return row;

    }

}

异步类

public class FilmRequestAsync extends AsyncTask<String, Void, List<FilmRequest>>{

    Context context;
    ListView listView;
    private ProgressDialog progressDialog;

    public FilmRequestAsync (Context context) {
        this.context=context;
        this.listView=(ListView) ((Activity)context).findViewById(R.id.FilmRequestList);
    }

    protected void onPreExecute() {
        this.progressDialog = ProgressDialog.show(context, "Lütfen Bekleyin...", "Fimler Yükleniyor...",true);
    }   

    @Override
    protected List<FilmRequest> doInBackground(String... params) {
        Log.d("debug","FilmRequestAsync param[0]"+params[0]);
        List<FilmRequest> filmRequests=null;
        String jsonString;

        try {
            jsonString=GeneralFunctions.getUrl(params[0]);
            if (jsonString!=null) {

                 filmRequests=this.getFilmRequestListFromJsonString(jsonString);

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

        return filmRequests;        


    }

    private List<FilmRequest> getFilmRequestListFromJsonString(String jsonString){
        List<FilmRequest> filmRequests=new ArrayList<FilmRequest>();
        try {
            Log.d("debug","Json Verisi oluşturuluyor.");
            JSONArray json=new JSONArray(jsonString);
            Log.d("debug","Json Verisi Oluşturuldu");

            int i;
            for (i=0;i<json.length();i++) {
                JSONObject tmpJson=(JSONObject)json.get(i);
                filmRequests.add(
                    new FilmRequest(
                            tmpJson.getString("id"),
                            tmpJson.getString("imdb_id"),
                            tmpJson.getString("poster"),
                            tmpJson.getString("title"),
                            tmpJson.getString("rating"),
                            tmpJson.getString("order"),
                            tmpJson.getString("status"),
                            tmpJson.getString("vote_count"),
                            tmpJson.getBoolean("requested"),
                            tmpJson.getBoolean("voted")
                            )
                );
                tmpJson=null;
            }

        } catch (JSONException e) {
            Log.d("debug","Json Verisi HATASI:");

            filmRequests=null;
            e.printStackTrace();
        }

        return filmRequests;        
    }

    @Override
    protected void onPostExecute(List<FilmRequest> result) {
            this.progressDialog.dismiss();
            if (result==null) return;

            // TODO Auto-generated method stub
            super.onPostExecute(result);
            Log.d("debug", "FilmRequestAsync onPostExecute Başı");

            FilmRequestAdapter filmRequestAdapter=new FilmRequestAdapter(context, R.layout.film_request_list, result);
            Log.d("debug","FilmRequestAsync:Adapter set ediliyor.");
            listView.setAdapter(filmRequestAdapter);
            Log.d("debug", "onPostExecute Sonu");
        }
}

列出Xml文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/film_container"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="2dp"
    android:background="@drawable/film_list_style"
    android:orientation="horizontal"
    android:padding="3dp" >

    <!--  ListRow Left sied Thumbnail image -->

    <!-- Title Of Song-->

    <!-- Artist Name -->

    <!-- Rightend Duration -->

    <ImageView
        android:id="@+id/FilmRequestPoster"
        android:layout_width="83dp"
        android:layout_height="106dp" />

    <Button
        android:id="@+id/FilmRequestActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:text="+ Oyla" />

    <TextView
        android:id="@+id/FilmRequestRating"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/FilmRequestFilmTitle"
        android:layout_below="@+id/FilmRequestFilmTitle"
        android:text="Rating" />

    <TextView
        android:id="@+id/FilmRequestVoteCount"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/FilmRequestOrder"
        android:layout_below="@+id/FilmRequestOrder"
        android:text="VoteCount" />

    <TextView
        android:id="@+id/FilmRequestFilmTitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignTop="@+id/FilmRequestActionButton"
        android:layout_toRightOf="@+id/FilmRequestPoster"
        android:text="Rihanna Love the way lie"
        android:textColor="#040404"
        android:textSize="15dip"
        android:textStyle="bold"
        android:typeface="sans" />

    <TextView
        android:id="@+id/FilmRequestOrder"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/FilmRequestRating"
        android:layout_toRightOf="@+id/FilmRequestPoster"
        android:text="Order" />

</RelativeLayout>

单击“功能”

    public static void ButtonClickFunction(Context context, Button button){
        //Burası Ne işlem yapabileceğimizi gösteriyor.
        //REQUESTABLE veya VOTABLE değerleri alabilir.
        String action=(String)button.getTag(R.string.film_request_action);
        String id=(String)button.getTag(R.string.film_request_id);

        Log.d("debug", "String action="+action);

        if (action.equalsIgnoreCase("VOTEABLE")) {
            VoteFilm(context, button,id);
        } else if (action.equalsIgnoreCase("REQUESTABLE")) {
            RequestFilm(context, button, id);
        }
    }   

    public static void VoteFilm(Context context, final Button button, final String id){
        final String callUrl=context.getString(R.string.api_url)+"?request=vote_film&user_id=1&id="+id;
        Log.d("debug", "FilmRequestActivity->VoteFilm->callUrl:"+callUrl);
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    GeneralFunctions.getUrl(callUrl);
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                button.post(new Runnable() {
                    @Override
                    public void run() {
                        button.setText("Oylanmış");
                        button.setEnabled(false);
                    }
                });
            }
        }).start();
        Toast.makeText(context, "Film Oylandı", Toast.LENGTH_SHORT).show(); 
    }

    public static void RequestFilm(Context context, final Button button,final String id){
        final String callUrl=context.getString(R.string.api_url)+"?request=request_film&user_id=1&id="+id;
        Log.d("debug", "FilmRequestActivity->RequestFilm->callUrl:"+callUrl);

        new Thread(new Runnable() {

            @Override
            public void run() {
                String jsonString;
                final JSONObject jsonObject;
                try {
                    jsonString = GeneralFunctions.getUrl(callUrl);
                    jsonObject=GeneralFunctions.StringToJSONObject(jsonString);
                    if (jsonObject!=null) {
                        button.post(new Runnable() {
                            @Override
                            public void run() {

                                try {
                                    Log.d("debug","Inside Thread");
                                    JSONObject data=(JSONObject) jsonObject.get("data");
                                    String new_id=data.getString("id");
                                    button.setTag(R.string.film_request_action,"VOTEABLE");
                                    button.setTag(R.string.film_request_id,new_id);
                                    button.setText("+Oyla");
                                    button.setEnabled(true);

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

                            }
                        });

                    }                   
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();

    }
}

Answer 1

问题是，在致电ButtonClickFunction时，您永远不会修改适配器的内容。这样滚动时，会保持保持状态，旧字符串将设置为按钮。我建议你更好地考虑你的设计。作为快速修复，您可以为Button设置另一个标记，在位置添加FilmRequest对象，例如：

    final FilmRequest filmRequest = (FilmRequest)data.get(position);
    String status = filmRequest.status;
    boolean requested = filmRequest.requested;
    boolean voted = filmRequest.voted;

然后，在ButtonClickFunction内，检索此标记并相应地更改其status

Answer 2

您没有正确使用ViewHolder模式。您必须创建一个ViewHolder并使用setTag和getTag来存储项目的状态：

    if (convertView == null) {
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }

Answer 3

我是同一个问题，但我通过此代码解决

public class CustomizeListView extends ListActivity {

    LayoutInflater inflater;
    static int index = 0;

    // AutoCompleteTextView autoCompleteTextView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_order);
        inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, arrayList_Category);
        dataAdapter
                .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        final CustomAdapter adapter = new CustomAdapter(this,
                R.layout.activity_orderitem, arrayListItems);
        setListAdapter(adapter);
    }

    private class CustomAdapter extends ArrayAdapter<HashMap<String, Object>>
            implements OnItemSelectedListener {
        boolean[] checkBoxState;
        ViewHolder viewHolder;

        public CustomAdapter(Context context, int textViewResourceId,
                ArrayList<HashMap<String, Object>> arrayListItems) {
            // let android do the initializing :)
            super(context, textViewResourceId, arrayListItems);
            checkBoxState = new boolean[arrayListItems.size()];
        }

        // class for caching the views in a row
        private class ViewHolder {
            CheckBox checkBox;
        }

        @Override
        public View getView(final int position, View convertView,
                ViewGroup parent) {
            Log.d("getView", "getView");
            if (convertView == null) {
                convertView = inflater.inflate(R.layout.activity_orderitem,
                        null);
                viewHolder = new ViewHolder();
                // cache the views
                convertView.setTag(viewHolder);
            } else
                viewHolder = (ViewHolder) convertView.getTag();

            viewHolder.checkBox.setChecked(checkBoxState[position]);

            viewHolder.checkBox.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    if (((CheckBox) v).isChecked()) {
                        checkBoxState[position] = true;
                    } else {
                        checkBoxState[position] = false;
                    }
                }
            });

            return convertView;
        }
    }
}

Answer 4

在我看来，您正在使用视图来存储其状态，因此当视图在滚动中被回收时，原始元素将丢失状态，甚至可以将状态分配给获取回收视图的其他元素。尝试存储不在视图中但在适配器中的不同结构中的元素的状态。

修改按钮重置滚动ListView

4 个答案: