Android 一键清理、内存清理功能实现

/** 

       * Constant for {@link #importance}: this is a persistent process. 

       * Only used when reporting to process observers. 

       * @hide 

       */ 

      publicstaticfinalintIMPORTANCE_PERSISTENT =50; 

      /** 

       * Constant for {@link #importance}: this process is running the 

       * foreground UI. 

       */ 

      publicstaticfinalintIMPORTANCE_FOREGROUND =100; 

      /** 

       * Constant for {@link #importance}: this process is running something 

       * that is actively visible to the user, though not in the immediate 

       * foreground. 

       */ 

      publicstaticfinalintIMPORTANCE_VISIBLE =200; 

      /** 

       * Constant for {@link #importance}: this process is running something 

       * that is considered to be actively perceptible to the user. An 

       * example would be an application performing background music playback. 

       */ 

      publicstaticfinalintIMPORTANCE_PERCEPTIBLE =130; 

      /** 

       * Constant for {@link #importance}: this process is running an 

       * application that can not save its state, and thus can't be killed 

       * while in the background. 

       * @hide 

       */ 

      publicstaticfinalintIMPORTANCE_CANT_SAVE_STATE =170; 

      /** 

       * Constant for {@link #importance}: this process is contains services 

       * that should remain running. 

       */ 

      publicstaticfinalintIMPORTANCE_SERVICE =300; 

      /** 

       * Constant for {@link #importance}: this process process contains 

       * background code that is expendable. 

       */ 

      publicstaticfinalintIMPORTANCE_BACKGROUND =400; 

      /** 

       * Constant for {@link #importance}: this process is empty of any 

       * actively running code. 

       */ 

      publicstaticfinalintIMPORTANCE_EMPTY =500;

packagecom.example.demo;

importjava.util.List;

importandroid.app.Activity;

importandroid.app.ActivityManager;

importandroid.app.ActivityManager.MemoryInfo;

importandroid.app.ActivityManager.RunningAppProcessInfo;

importandroid.content.Context;

importandroid.content.pm.PackageManager;

importandroid.content.pm.PackageManager.NameNotFoundException;

importandroid.os.Bundle;

importandroid.util.Log;

importandroid.view.Menu;

importandroid.view.MenuItem;

importandroid.view.View;

importandroid.widget.Toast;

publicclassCleanProcessActivityextendsActivity {

  privatestaticfinalString TAG ="Clean";

  @Override

  protectedvoidonCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_clean_process);

  }

  publicvoidclean(View v){

    //To change body of implemented methods use File | Settings | File Templates. 

    ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE); 

    List infoList = am.getRunningAppProcesses(); 

    List serviceInfos = am.getRunningServices(100); 

    longbeforeMem = getAvailMemory(this); 

    Log.d(TAG,"-----------before memory info : "+ beforeMem); 

    intcount =0; 

    PackageManager pm = getPackageManager();

    if(infoList !=null) { 

      for(inti =0; i < infoList.size(); ++i) { 

        RunningAppProcessInfo appProcessInfo = infoList.get(i); 

        Log.d(TAG,"process name : "+ appProcessInfo.processName); 

        //importance 该进程的重要程度 分为几个级别，数值越低就越重要。 

        Log.d(TAG,"importance : "+ appProcessInfo.importance); 

        // 一般数值大于RunningAppProcessInfo.IMPORTANCE_SERVICE的进程都长时间没用或者空进程了 

        // 一般数值大于RunningAppProcessInfo.IMPORTANCE_VISIBLE的进程都是非可见进程，也就是在后台运行着 

        if(appProcessInfo.importance > RunningAppProcessInfo.IMPORTANCE_VISIBLE) { 

          String[] pkgList = appProcessInfo.pkgList; 

          for(intj =0; j < pkgList.length; ++j) {//pkgList 得到该进程下运行的包名 

            String appName =null;

            try{

              appName = (String) pm.getApplicationLabel(pm.getApplicationInfo(pkgList[j],0)); 

            }catch(NameNotFoundException e) {

              // TODO Auto-generated catch block

              e.printStackTrace();

            }

            Log.d(TAG,"It will be killed, package name : "+ pkgList[j]+" -- "+appName ); 

            am.killBackgroundProcesses(pkgList[j]); 

            count++; 

          } 

        } 

      } 

    } 

    longafterMem = getAvailMemory(this); 

    Log.d(TAG,"----------- after memory info : "+ afterMem); 

    Toast.makeText(this,"clear "+ count +" process, " 

          + (afterMem - beforeMem) +"M", Toast.LENGTH_LONG).show(); 

  }

  privatelonggetAvailMemory(CleanProcessActivity cleanProcessActivity) {

    // 获取android当前可用内存大小 

    ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE); 

    MemoryInfo mi =newMemoryInfo(); 

    am.getMemoryInfo(mi); 

    //mi.availMem; 当前系统的可用内存 

    //return Formatter.formatFileSize(context, mi.availMem);// 将获取的内存大小规格化 

    Log.d(TAG,"可用内存---->>>"+ mi.availMem / (1024*1024)); 

    returnmi.availMem / (1024*1024); 

  } 

}