刷新列表视图以从那里删除项目

Question

嘿，伙计，我正在开发包含列表视图的应用程序，其中安装的应用程序填充了一些按钮，例如卸载。

public class MainActivity extends ListActivity {
PackageManager packageManager;
List<ApplicationInfo> applist;
Listadapter listadapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    packageManager = getPackageManager();

    new LoadApplications().execute();

}

@Override
protected void onListItemClick(ListView l, View v, final int position, long id) {
    super.onListItemClick(l, v, position, id);
         AlertDialog.Builder dialogBuilder = new   AlertDialog.Builder(this);
    dialogBuilder.setTitle("Choose option")
            .setItems(R.array.options, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    switch (which) {
                        case 0:
                            ApplicationInfo app = applist.get(position);
                            try {
                                Intent intent = packageManager.getLaunchIntentForPackage(app.packageName);

                                if (intent != null) {
                                    startActivity(intent);
                                }
                            } catch (ActivityNotFoundException e) {
                                Toast.makeText(MainActivity.this, e.getMessage(), Toast.LENGTH_LONG).show();
                            } catch (Exception e) {
                                Toast.makeText(MainActivity.this, e.getMessage(), Toast.LENGTH_LONG).show();
                            }
                            break;
                        case 1:
                            ApplicationInfo app1 = applist.get(position);
                            Uri packageURI = Uri.parse("package:" + app1.packageName);
                            Intent uninstallIntent = new Intent(Intent.ACTION_DELETE, packageURI);
                            startActivity(uninstallIntent);
                            applist.remove(listadapter.getItem(position));
                            listadapter.notifyDataSetChanged();
                            break;
                        case 2:
                            break;
                    }
                }
            });
    dialogBuilder.setCancelable(true)
            .show();

}

private List<ApplicationInfo> checkForLaunchIntent(List<ApplicationInfo> list) {
    ArrayList<ApplicationInfo> applist = new ArrayList<>();

    for (ApplicationInfo info : list) {
        try {
            if (packageManager.getLaunchIntentForPackage(info.packageName) != null) {
                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));

        listadapter = new Listadapter(MainActivity.this, R.layout.list_item, applist);

        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        setListAdapter(listadapter);
        progress.dismiss();
        super.onPostExecute(aVoid);

    }

    @Override
    protected void onPreExecute() {
        progress = ProgressDialog.show(MainActivity.this, null, "loading apps info,,,");
        super.onPreExecute();
    }

}

@Override
protected void onPause() {
    super.onPause();
        listadapter.notifyDataSetInvalidated();
}

当我点击卸载时，应用位置在卸载应用之前先被删除。

这是strings.xml

<resources>
    <string name="app_name">AppSharer</string>
    <string-array name="options">
        <item>Open App</item>
        <item>uninstall</item>
    </string-array>
</resources>

删除项目后我应该如何刷新列表视图。

谢谢！！！

Answer 1

我从问题中得到的是，如果用户单击“是”进行卸载，但用户从设置屏幕返回应用程序而不卸载它，那么您一定会遇到问题。在这种情况下，如果用户在卸载时单击“是”并将应用程序包名称保存在实例级别的字符串变量中并在类的恢复方法中检查用户布尔值是否为真然后检查定义的包是否存在，则创建一个变量布尔值，然后检查是否存在定义的包和如果它不存在更新您的列表视图。请参考这个，我还添加了 cmets 来通知你做了哪些更改

 public class MainActivity extends ListActivity {
    PackageManager packageManager;
    List<ApplicationInfo> applist;
    Listadapter listadapter;
    // add three variables
    String packageName="";
    boolean isUnInstallClicked;
    int mPosition;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        packageManager = getPackageManager();

        new LoadApplications().execute();

    }

    @Override
    protected void onListItemClick(ListView l, View v, final int position, long id) {
        super.onListItemClick(l, v, position, id);
             AlertDialog.Builder dialogBuilder = new   AlertDialog.Builder(this);
        dialogBuilder.setTitle("Choose option")
                .setItems(R.array.options, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        switch (which) {
                            case 0:
                                ApplicationInfo app = applist.get(position);
                                try {
                                    Intent intent = packageManager.getLaunchIntentForPackage(app.packageName);

                                    if (intent != null) {
                                        startActivity(intent);
                                    }
                                } catch (ActivityNotFoundException e) {
                                    Toast.makeText(MainActivity.this, e.getMessage(), Toast.LENGTH_LONG).show();
                                } catch (Exception e) {
                                    Toast.makeText(MainActivity.this, e.getMessage(), Toast.LENGTH_LONG).show();
                                }
                                break;
                            case 1:
                                ApplicationInfo app1 = applist.get(position);
                                Uri packageURI = Uri.parse("package:" + app1.packageName);
                                Intent uninstallIntent = new Intent(Intent.ACTION_DELETE, packageURI);
                                startActivity(uninstallIntent);
                                //remove applist.remove and notify from here and add it to on resume
                                packageName=app1.packageName;
                                isUnInstallClicked=true;
                                mPosition=position;

                                break;
                            case 2:
                                break;
                        }
                    }
                });
        dialogBuilder.setCancelable(true)
                .show();

    }
    @Override
        protected void onResume() {
            // TODO Auto-generated method stub
            super.onResume();
            // here check for whether unistall was clicked and was app unistalled
            if(isUnInstallClicked && !appInstalledOrNot(packageName)){
                //check whther app unistalled or not

                applist.remove(listadapter.getItem(position));
                listadapter.notifyDataSetChanged();
                }
            }
        }
    private boolean appInstalledOrNot(String uri) {
        PackageManager pm = getPackageManager();
        boolean app_installed;
        try {
            pm.getPackageInfo(uri, PackageManager.GET_ACTIVITIES);
            app_installed = true;
        }
        catch (PackageManager.NameNotFoundException e) {
            app_installed = false;
        }
        return app_installed;
    }
    private List<ApplicationInfo> checkForLaunchIntent(List<ApplicationInfo> list) {
        ArrayList<ApplicationInfo> applist = new ArrayList<>();

        for (ApplicationInfo info : list) {
            try {
                if (packageManager.getLaunchIntentForPackage(info.packageName) != null) {
                    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));

            listadapter = new Listadapter(MainActivity.this, R.layout.list_item, applist);

            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            setListAdapter(listadapter);
            progress.dismiss();
            super.onPostExecute(aVoid);

        }

        @Override
        protected void onPreExecute() {
            progress = ProgressDialog.show(MainActivity.this, null, "loading apps info,,,");
            super.onPreExecute();
        }

    }

    @Override
    protected void onPause() {
        super.onPause();
            listadapter.notifyDataSetInvalidated();