您可以做这样的事情，但不建议：

You can do something like this,but it is not recommended:

    List<ApplicationInfo> packages;
    PackageManager pm;
    pm = getPackageManager();
    //get a list of installed apps.
    packages = pm.getInstalledApplications(0);

    ActivityManager mActivityManager = (ActivityManager)context.getSystemService(Context.ACTIVITY_SERVICE);

   for (ApplicationInfo packageInfo : packages) {
        if((packageInfo.flags & ApplicationInfo.FLAG_SYSTEM)==1)continue;
        if(packageInfo.packageName.equals("mypackage")) continue;
        mActivityManager.killBackgroundProcesses(packageInfo.packageName);
   }