java - 无法在扩展 ArrayAdapter 的类中解析方法 super

Question

在我创建的 Android 应用程序中，我有一个可滚动的选项卡，在其中一个 fragment 中，我试图显示所有用户下载的应用程序。

我正在尝试使用一个 fragment 来实现它

http://javatechig.com/android/how-to-get-list-of-installed-apps-in-android

我的应用程序类扩展了 Fragment。该类用于初始化和列出已安装的应用程序。因为从 PackageManage 获取应用程序详细信息列表是一项长期运行的任务。

此外，该类使用扩展 ArrayAdapter 的 ApplicationAdapter 类。

我的 ApplicationAdapter 类收到此错误。

我想弄清楚为什么 super 无法解析以及如何修复它。不应该一开始就调用吗？

这是我的 ApplicationAdapter 类的 java 代码:

package com.javatechig.listapps;

import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import com.spicycurryman.getdisciplined10.app.InstalledAppActivity;
import com.spicycurryman.getdisciplined10.app.R;

import java.util.List;







public class ApplicationAdapter extends ArrayAdapter<ApplicationInfo> {
    private List<ApplicationInfo> appsList = null;
    private InstalledAppActivity context;
    private PackageManager packageManager;

           public ApplicationAdapter(InstalledAppActivity context, int textViewResourceId,
                                          List<ApplicationInfo> appsList) {
        super(context, textViewResourceId, appsList);
        this.context = context;
       this.appsList = appsList;
        packageManager = context.getActivity().getPackageManager();
      }

            @Override
    public int getCount() {
        return ((null != appsList) ? appsList.size() : 0);
       }

           @Override
    public ApplicationInfo getItem(int position) {
        return ((null != appsList) ? appsList.get(position) : null);
        }

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

            @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View view = convertView;
        if (null == view) {
            LayoutInflater layoutInflater = (LayoutInflater) context.getActivity().
            getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = layoutInflater.inflate(R.layout.snippet_list_row, null);
            }

        ApplicationInfo data = appsList.get(position);
        if (null != data) {
           TextView appName = (TextView) view.findViewById(R.id.app_name);
           TextView packageName = (TextView) view.findViewById(R.id.app_package);
            ImageView iconview = (ImageView) view.findViewById(R.id.app_icon);

            appName.setText(data.loadLabel(packageManager));
            packageName.setText(data.packageName);
            iconview.setImageDrawable(data.loadIcon(packageManager));
           }
        return view;
        }
};

如果在这里显示我的 fragment 类有任何用处，那就是:

package com.spicycurryman.getdisciplined10.app;

import android.app.ProgressDialog;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.Toast;

import com.javatechig.listapps.ApplicationAdapter;

import java.util.ArrayList;
import java.util.List;


public class InstalledAppActivity extends Fragment {
    private PackageManager packageManager = null;
    private List<ApplicationInfo> applist = null;
    private ApplicationAdapter listadaptor = null;

    ListView InstalledAppList;

    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        packageManager = (PackageManager) getActivity().getPackageManager().getInstalledPackages(0);
        new LoadApplications().execute();

        InstalledAppList.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                ApplicationInfo app = applist.get(i);
                try {
                    Intent intent = packageManager
                            .getLaunchIntentForPackage(app.packageName);

                    if (null != intent) {
                        startActivity(intent);
                    }
                }

                catch (ActivityNotFoundException e) {
                    Toast.makeText(getActivity(),"",Toast.LENGTH_SHORT).show();

                }
            }



        });
        return inflater.inflate(R.layout.installed_apps, container, false);

    }


    private List<ApplicationInfo> checkForLaunchIntent(List<ApplicationInfo> list) {
        ArrayList<ApplicationInfo> applist = new ArrayList<ApplicationInfo>();
        for (ApplicationInfo info : list) {
            try {
                if (null != packageManager.getLaunchIntentForPackage(info.packageName)) {
                    applist.add(info);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        return applist;
    }

    private class LoadApplications extends AsyncTask<Void, Void, Void> {
        private ProgressDialog progress = null;

        @Override
        protected Void doInBackground(Void... params) {
            applist = checkForLaunchIntent(packageManager.getInstalledApplications(PackageManager.GET_META_DATA));
            listadaptor = new ApplicationAdapter(InstalledAppActivity.this,
                    R.layout.snippet_list_row, applist);

            return null;
        }

        @Override
        protected void onCancelled() {
            super.onCancelled();
        }

        @Override
        protected void onPostExecute(Void result) {
            //setListAdapter(listadaptor);
            InstalledAppList.setAdapter(listadaptor);
            super.onPostExecute(result);
        }



        @Override
        protected void onProgressUpdate(Void... values) {
            super.onProgressUpdate(values);
        }
    }
}

错误是:

Cannot resolve method 'super(com.spicycurryman.getdisciplined10.app.InstalledActivity,int,java.util.List'

Answer 1

看起来 InstalledActivity 没有扩展/实现 Context，因此它不适用于任何 ArrayAdapter构造函数子句。