java - AsyncTask 不使用 BaseAdpter 创建 GridView

Question

我是 Android 开发新手，对此有非常基本的了解，到目前为止我所取得的成就都是使用这个网站或 youtube 视频实现的，我陷入了 AsyncTask (早些时候我在 Create View 上使用 .get() 并且它正在工作)很好，但是 UI 被阻止，直到任务完成。为了避免 UI 阻塞，我建议在删除此函数后立即从 OnCreateView() 函数中删除 .get() 函数，因为我无法从 AsyncTask 获取任何数据。我这样做了，但现在我无法创建 View ，我做了很多研究，但无法获得这种优势

这是我的代码，请帮助如何从中创建 View

OnCreateView() :-

    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
    View GView = inflater.inflate(R.layout.fragment_dashboard, container, false);
    progressBarHolder = (FrameLayout) GView.findViewById(R.id.progressBarHolder);
    GridView gridView = (GridView) GView.findViewById(R.id.gridView);
    //Toast.makeText(getActivity(),Json_String,Toast.LENGTH_LONG).show();
    String finalResult = null;
    try{
        finalResult = String.valueOf(new JSONTask().execute("https://www.example.in/android_api/dashboard_data",JsonData()));
        Toast.makeText(getActivity(),Json_String,Toast.LENGTH_LONG).show();
        JSONObject parentObject = null;
        parentObject = new JSONObject(finalResult);
        if(((String) parentObject.names().get(0)).matches("error")){
            JSONObject jObj = parentObject.getJSONObject("error");
            errorThrow(jObj.getString("Description"));
        } else if(((String) parentObject.names().get(0)).matches("success")){
            JSONObject jObj = parentObject.getJSONObject("success");
            JSONArray arrajson = jObj.getJSONArray("data");
            String arrayCount = Integer.toString(arrajson.length());
            String[] type = new String[arrajson.length()];
            Integer[] count = new Integer[arrajson.length()];
            for (int i=0; i<arrajson.length();i++){
                JSONObject jsonObject = arrajson.getJSONObject(i);
                type[i] = jsonObject.getString("type");
                count[i] = jsonObject.getInt("count");
            }
            CustomAdpter customAdpter = new CustomAdpter(DashboardFragment.this,type,count);
            gridView.setAdapter(customAdpter);
            return GView;
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }
    return GView;
}

基础适配器代码:-

    class CustomAdpter extends BaseAdapter {

    String[] type;
    Integer[] count;
    public CustomAdpter(DashboardFragment dashboardFragment, String[] type, Integer[] count){
        this.count = count;
        this.type = type;
    }
    @Override
    public int getCount() {
        return type.length;
    }

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

    @Override
    public long getItemId(int i) {
        return 0;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        view = getLayoutInflater().inflate(R.layout.grid_single_itme,null);
        TextView textView = (TextView) view.findViewById(R.id.TextView1);
        TextView textView1 = (TextView) view.findViewById(R.id.textView2);
        textView.setText(String.valueOf(count[i]));
        textView1.setText(type[i]);
        view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(getActivity(),"Booking Item Clicked",Toast.LENGTH_LONG).show();
            }
        });
        return view;
    }
}

异步任务代码:-

    public class JSONTask extends AsyncTask<String,String,String> {
    private ProgressDialog mProgressDialog;

    int progress;
    public JSONTask(){
        mProgressDialog = new ProgressDialog(getContext());
        mProgressDialog.setMax(100);
        mProgressDialog.setProgress(0);
    }

    @Override
    protected void onPreExecute(){
        mProgressDialog = ProgressDialog.show(getContext(),"Loading","Loading Data...",true,false);
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... params) {
        HttpURLConnection connection = null;
        BufferedReader reader = null;
        final String finalJson = params[1];
        String json = finalJson;
        try{
            URL url = new URL(params[0]);
            connection = (HttpURLConnection) url.openConnection();
            connection.setConnectTimeout(5000);
            connection.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
            connection.setRequestProperty("A-APK-API", "******");
            connection.setRequestProperty("Authorization", "Basic **:**");
            connection.setDoOutput(true);
            connection.setDoInput(true);
            connection.setRequestMethod("POST");
            connection.connect();

            OutputStream stream = connection.getOutputStream();
            OutputStreamWriter streams =  new OutputStreamWriter(stream, "UTF-8");
            stream.write(json.getBytes("UTF-8"));
            stream.close();

            reader = new BufferedReader(new InputStreamReader(connection.getInputStream(),"UTF-8"));

            StringBuffer buffer = new StringBuffer();

            String line = "";
            while((line = reader.readLine()) != null){
                buffer.append(line);
            }
            return buffer.toString();

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(connection != null){
                connection.disconnect();
            }
            try {
                if(reader != null) {
                    reader.close();
                }
            } catch (IOException e){
                e.printStackTrace();
            }
        }
        return null;
    }
    protected void onPostExecute(String result){
        super.onPostExecute(result);
        Json_String = result;
        Toast.makeText(getContext(),result,Toast.LENGTH_LONG).show();
        mProgressDialog.dismiss();
    }
}

请帮助我

Answer 1

当您不使用 .get() 时，您无法从 asynctask 获取结果。

所以改变这个说法。仅启动异步任务。

然后将该行之后的所有代码放入 AsyncTask 的 onPostExecute() 中。

仅此而已。