在继续之前等待接收多个广播消息

Question

我有一个使用插件系统的应用。这些“插件”会发出一条广播消息，然后我的应用会收到该消息并使用附加的相关数据来注册该应用。

问题是我不知道在任何给定时间设备上安装了多少插件，所以我不知道要等待多少消息，而且我不知道有什么方法可以检查它是否是最后一条消息正在发送。

现在我正在通过等待三秒计时器完成伪装，允许插件注册三秒钟，但随着更多插件的开发，这不会是足够的时间。

如果所有插件都已完成注册，我该如何刷新我的UI？

PanelReceiver.java

package com.t3hh4xx0r.haxlauncher.menu.livepanel;

import java.io.ByteArrayOutputStream;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.res.Resources;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.Log;

import com.t3hh4xx0r.haxlauncher.DBAdapter;

public class PanelReceiver extends BroadcastReceiver {
    private static final String PANEL_REQUEST = "com.t3hh4xx0r.haxlauncher.PANEL_REQUEST";
    private static final String PANEL_REGISTER = "com.t3hh4xx0r.haxlauncher.PANEL_REGISTER";
    private static final String PANEL_UPDATE = "com.t3hh4xx0r.haxlauncher.PANEL_UPDATE";

    boolean shouldAdd = true;
    @Override
    public void onReceive(Context context, Intent intent) {
        String a = intent.getAction();
        if (a.equals(PANEL_REGISTER)) {
            Bundle b = intent.getExtras();
            String author = b.getString("author_name");
            String plugin = b.getString("plugin_name");
            String packageN = b.getString("package_name");
            String desc = b.getString("description");
            String version = b.getString("version");

            DBAdapter db = new DBAdapter(context);
            db.open();      
            Cursor c = db.getAllPanels();
            if (c.getCount() != 0) {
                while (c.moveToNext()) {
                    if (c.getString(c.getColumnIndex("author")).equals(author) &&
                            c.getString(c.getColumnIndex("package")).equals(packageN)){
                        shouldAdd = false;
                        if (!c.getString(c.getColumnIndex("version")).equals(version)) {
                            db.removePanel(packageN);
                            shouldAdd = true;
                        }               
                    }
                }
            }
            if (shouldAdd) {            
                db.insertPanel(version, author, plugin, packageN, desc, image("ic_launcher", context, packageN), image("screencap", context, packageN));
            }
            db.close();     
        } else if (a.equals(PANEL_UPDATE)) {
            Log.d("UPDATE", "OMFG!");
        }
    }

    public static void requestPanels(Context context) {
        Intent i = new Intent();
        i.setAction(PANEL_REQUEST);
        context.sendBroadcast(i); 
    }

    public byte[] image(String imageName, Context c, String packageN) {
        try {
            Context fC = c.getApplicationContext().createPackageContext(packageN, Context.CONTEXT_IGNORE_SECURITY);
            Resources res = fC.getResources();          
            Bitmap photo = drawableToBitmap(res.getDrawable(res.getIdentifier(imageName, "drawable", packageN)));
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            photo.compress(Bitmap.CompressFormat.PNG, 100, bos);
            return bos.toByteArray();
        } catch (NameNotFoundException e) {
            return null;    
        }  
    };

    public static Bitmap drawableToBitmap (Drawable drawable) {
        if (drawable instanceof BitmapDrawable) {
            return ((BitmapDrawable)drawable).getBitmap();
        }

        Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap); 
        drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        drawable.draw(canvas);
        return bitmap;
    }
}

PanelMenuActivity.java

package com.t3hh4xx0r.haxlauncher.menu.livepanel;

import java.util.ArrayList;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.database.Cursor;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;

import com.t3hh4xx0r.haxlauncher.DBAdapter;
import com.t3hh4xx0r.haxlauncher.R;

public class PanelMenuActivity extends Activity {
    ListView lv;
    static ArrayAdapter<String> a;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.panel_menu);

        lv = (ListView) findViewById(R.id.panel_list);
        lv.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> a, View v, int pos,
                    long id) {
                Intent i = new Intent(v.getContext(), PanelDetails.class);
                Bundle b = new Bundle();
                b.putInt("pos", ((PanelDetailHolder)a.getItemAtPosition(pos)).id);
                i.putExtras(b);
                startActivity(i);
            }           
        });
        GetPanelsTask t = new GetPanelsTask();
        t.execute();
    }

    private ListAdapter buildAdapter(Context c) {
        return new PanelAdapter(this, getPanels(c));
    }

    public ArrayList<PanelDetailHolder> getPanels(Context ctx) {
        ArrayList<PanelDetailHolder> panelArray = new ArrayList<PanelDetailHolder>();       
        DBAdapter db = new DBAdapter(ctx);
        db.open();
        Cursor c = db.getAllPanels();
        while (c.moveToNext()) {
            try{
                 getPackageManager().getApplicationInfo(c.getString(c.getColumnIndex("package")), 0 );
                } catch (NameNotFoundException e){
                    db.removePanel(c.getString(c.getColumnIndex("package")));
                    continue;           
                }
            PanelDetailHolder p = new PanelDetailHolder();
            p.author = c.getString(c.getColumnIndex("author"));
            p.title = c.getString(c.getColumnIndex("name"));
            p.desc = c.getString(c.getColumnIndex("desc"));
            p.version = c.getString(c.getColumnIndex("version"));
            p.id = c.getPosition();
            panelArray.add(p);
        }
        c.close();
        db.close();
        return panelArray;
    }

    @Override
    public boolean onOptionsItemSelected(android.view.MenuItem item) {
        int id = item.getItemId();
        switch (id) {
            case R.id.refresh:
                GetPanelsTask t = new GetPanelsTask();
                t.execute();    
        }
        return false;
    }
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater menuinflate = new MenuInflater(this);
        menuinflate.inflate(R.menu.panel_menu, menu);
        return true;
    }


    public class GetPanelsTask extends AsyncTask<Object, View, Void> {
        ProgressDialog progressDialog;
        @Override
        protected void onPreExecute() {
            progressDialog= ProgressDialog.show(PanelMenuActivity.this, 
                    "Loading...","Checking for live panels...", true);
            PanelReceiver.requestPanels(PanelMenuActivity.this);

        };      
        @Override
        protected Void doInBackground(Object... params) {
            try {
                Thread.sleep(300);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            return null;
        };      
        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);
            progressDialog.dismiss();
            lv.setAdapter(buildAdapter(PanelMenuActivity.this));        
        }

     }

    class PanelDetailHolder {
        String author;
        String title;
        String desc;
        String version;
        Drawable screenCap;
        Drawable icon;
        int id;
    }
}

Answer 1

  

如果所有插件都已完成注册，我该如何刷新我的UI？

根据定义，这是不可能的。您需要修改插件系统，以便：

• 您“知道设备上安装了多少个插件”或
• 您无需等待（甚至真正关心）“设备上安装了多少个插件”