Question

我是android的新手。实际上我试图通过我的应用程序增加Android手机的RAM内存。因为我创建了一个活动，我可以启动我们手机中的其他应用程序。这种方法是成功的减少RAM内存。但我面临一个困难，因为我在应用程序启动后无法看到PARENT活动。我需要推动其他活动（已启动）在启动后立即在后台运行，并且我总是需要显示父活动..

package com.android;

import java.util.List;
import android.app.Activity;
import android.app.ActivityManager;
import android.app.ActivityManager.MemoryInfo;
import android.content.ActivityNotFoundException;
import android.content.ComponentName;
import android.content.Context;
import android.content.ContextWrapper;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.os.Bundle;
import android.os.Handler;
import android.widget.LinearLayout;
import android.widget.Toast;
/**
 * GraphViewDemo creates some dummy data to demonstrate the GraphView component.
 * @author Arno den Hond
 **/
public class VsActivity extends Activity {
  /**
     * Variable Array for GraphView
     * verlabel : Background Height Values
     * horlabel : Background Width Values
     * values : Max Values of Foreground Active Graph
     */
    private float[] values = new float[60]; 
    long availableMegs;
    private String[] verlabels = new String[]     { "500","450","400","350","300","250","200","150","100","50","0"};
    private String[] horlabels = new String[] {"0","10", "20", "30", "40", "50", "60"};
    private GraphView graphView;
    private LinearLayout graph;
    private boolean runnable = false;
    public static int datasend,test=0;
    int cnt=0;
    Activity activity = this.activity;
    static int count=0;
    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        graph = (LinearLayout)findViewById(R.id.graph);
        graphView = new GraphView(this, values, "TEST GRAPH", horlabels, verlabels,    GraphView.LINE);
        graph.addView(graphView);
        runnable = true;
        startDraw.start();
    }

    @Override
    public void onDestroy(){
        super.onDestroy();
        runnable = false;
    }

    public void setGraph(){
        int i,j;
        count=count+10;
        try{
                j=values.length-1;
        for(i=0; i<values.length-1; i++){
            values[i] = values[i+1];
        }
        MemoryInfo mi = new ActivityManager.MemoryInfo();
        ActivityManager activityManager = (ActivityManager) getApplicationContext()
            .getSystemService(ACTIVITY_SERVICE);
        activityManager.getMemoryInfo(mi);
        datasend= (int)((mi.availMem / 1048576));
 values[values.length-1] = (float) datasend;        
graph.removeView(graphView);
        graph.addView(graphView);
        }
        catch (Exception e){
            // e.printstacktrace();
        }
    } 

private void  launchComponent(String packageName, String name){
    System.out.println("launch application "+datasend);
    Intent launch_intent = new Intent("android.intent.action.MAIN");
    launch_intent.addCategory("android.intent.category.LAUNCHER");
    launch_intent.setComponent(new ComponentName(packageName, name));
    launch_intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    if(datasend > 24){
        System.out.println("launch application inside if "+packageName+"   "+name);
    this.startActivity(launch_intent);
    }
}

public void startApplication(){
    String application_name = "";
    test=1;
    //ContextWrapper activity = this.activity;
    try{
        System.out.println("Start application ");
        Intent intent = new Intent("android.intent.action.MAIN");
        intent.addCategory("android.intent.category.LAUNCHER");
        List<android.content.pm.PackageInfo> packageList;
        intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        PackageManager pm = this.getPackageManager();
        packageList = pm.getInstalledPackages(0);
        List<ResolveInfo> resolveinfo_list = pm.queryIntentActivities(intent, 0);

        for(ResolveInfo info:resolveinfo_list){
            application_name = info.activityInfo.packageName;
            System.out.println(info.activityInfo.packageName+"    "+info.activityInfo.name);
            //if(info.activityInfo.packageName.equalsIgnoreCase(application_name)){
                launchComponent(info.activityInfo.packageName, info.activityInfo.name);
              //  break;
           // }
        }
    }
    catch (ActivityNotFoundException e) {
        Toast.makeText(activity.getApplicationContext(), "There was a problem loading the application: "+application_name,Toast.LENGTH_SHORT).show();
    }
}
public Handler handler = new Handler(){
    @Override
    public void handleMessage(android.os.Message msg){
        switch(msg.what){

        case 0x01:
           setGraph();
          // if(test == 0){
          startApplication();//}
           break;
        }
    }
};

public Thread startDraw = new Thread(){
    @Override
    public void run(){
        while(runnable){
            handler.sendEmptyMessage(0x01);
            try{
                MemoryInfo mi = new ActivityManager.MemoryInfo();
                ActivityManager activityManager = (ActivityManager)getSystemService(ACTIVITY_SERVICE);
                activityManager.getMemoryInfo(mi);
                long ava = mi.availMem / 1048576L;
                //count=(int)ava;
                //System.out.println("SUDARHAN RAMAN    "+ava+"   "+count);
                Thread.sleep(1000);
            } catch (Exception e){
                // e.printstacktrace();
            }
        }
    }
};
}

这里GraphView是一个使用Canvas.drawline（...）绘制图形的视图在上面的代码中， startapplication（）将启动子（安装在我们手机中的应用程序）活动。

Plz帮助...

Answer 1

     Intent i = new Intent(Intent.ACTION_MAIN);
            PackageManager manager = mContext.getPackageManager();
            i = manager.getLaunchIntentForPackage(_AppPkgName);
            i.addCategory(Intent.CATEGORY_LAUNCHER);
            startActivity(i);

通过应用程序安装启动应用程序（同时）的难度

1 个答案: