Android PakageManage

                                   Android PakageManage

     原创2016-12-18。

      PackageInfo,ApplicationInfo,ActivityInfo,ResolveInfo,ServiceInfo都是序列化的javaBean.

      PackageManager就是辅助类（获取这些bean）。

      PackageManage pm=context.getPackageManager();

      1.PackageInfo : apk的功能清单文件

        PackageInfo pi=pm.getPackageInfo(context.getPackageName(),0);ps:try一下.

        pi.versionCode 版本号；

        pi.versionName 版本名称;

        pi.packageName 包名;

      2.ApplicationInfo:<application>节点信息

        List<ApplicationInfo> appInfo=pm.getInstalledApplications(PackageManager.GET_UNINSTALLED_PACKAGES);// 

        String className=appInfo.get(i).loadLabel(pm);//lable,app的名字

        Drawable icon=appInfo.get(i).loadicon(pm);//icon,app的logo

        eg：查询所有已经安装的应用程序并启动：

    private void queryFilterAppInfo() {
        PackageManager pm = getAttchedActivity().getPackageManager();
        
        List<ApplicationInfo> appInfos = pm.getInstalledApplications(PackageManager.GET_UNINSTALLED_PACKAGES);// GET_UNINSTALLED_PACKAGES代表已删除，但还有安    装目录的
        List<ApplicationInfo> applicationInfos = new ArrayList<>();

         // 创建一个类别为CATEGORY_LAUNCHER的该包名的Intent
         Intent resolveIntent = new Intent(Intent.ACTION_MAIN, null);
         resolveIntent.addCategory(Intent.CATEGORY_LAUNCHER);

         // 通过getPackageManager()的queryIntentActivities方法遍历,得到所有能打开的app的packageName
         List<ResolveInfo> resolveinfoList = getAttchedActivity().getPackageManager()
                 .queryIntentActivities(resolveIntent, 0);
         Set<String> allowPackages = new HashSet();
         for (ResolveInfo resolveInfo : resolveinfoList) {
             allowPackages.add(resolveInfo.activityInfo.packageName);
        }
       ps:深绿色部分是遍历,得到所有能打开的app的packageNameadd到allowPackages中。

        for (ApplicationInfo app : appInfos) {
//       
            if (allowPackages.contains(app.packageName)) {
                applicationInfos.add(app);
            }
        }
        mApplicationInfos = applicationInfos;
    }      

   public static void doStartApplicationWithPackageName(Context context, String packagename) {
  
      PackageInfo packageinfo = null;
      try {
        packageinfo = context.getPackageManager().getPackageInfo(packagename, 0);
      } catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
      }
      if (packageinfo == null) {
         Toast.makeText(context, "程序无法启动", Toast.LENGTH_SHORT).show();
         return;
      }

    // 创建一个类别为CATEGORY_LAUNCHER的该包名的Intent
    Intent resolveIntent = new Intent(Intent.ACTION_MAIN, null);
    resolveIntent.addCategory(Intent.CATEGORY_LAUNCHER);
    resolveIntent.setPackage(packageinfo.packageName);

    // 通过getPackageManager()的queryIntentActivities方法遍历
    List<ResolveInfo> resolveinfoList = pm
            .queryIntentActivities(resolveIntent, 0);

    ResolveInfo resolveinfo = resolveinfoList.iterator().next();
    if (resolveinfo != null) {
        // packagename = 参数packname
        String packageName = resolveinfo.activityInfo.packageName;
        // 这个就是我们要找的该APP的LAUNCHER的Activity[组织形式：packagename.mainActivityname]
        String className = resolveinfo.activityInfo.name;
        // LAUNCHER Intent
        Intent intent = new Intent(Intent.ACTION_MAIN);
        intent.addCategory(Intent.CATEGORY_LAUNCHER);

        // 设置ComponentName参数1:packagename参数2:MainActivity路径
        ComponentName cn = new ComponentName(packageName, className);

        intent.setComponent(cn);
        context.startActivity(intent);
    }
}

        3.ActivityInfo:获得应用程序中<activity/>或者 <receiver />节点的信息

           eg：

    //    获取应用程序下所有activity
         public static ArrayList<String> getActivities(Context context, String packageName) {
     
          ArrayList<String> arrayActivities = new ArrayList<String>();
          PackageManager packageManager = context.getPackageManager();
           PackageInfo packageInfo = null;
          try {
              packageInfo = packageManager.getPackageInfo(packageName, PackageManager.GET_ACTIVITIES);
          } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
         ActivityInfo activitys[] = packageInfo.activities;
         if (activitys == null) {
             activitys = packageInfo.activities;
         }

          for (ActivityInfo info : activitys) {
              arrayActivities.add(info.name);
          }
         return arrayActivities;
    } 

        4.ServiceInfo: 同ActivityInfo类似 ，只不过它表示的是<service>节点信息

        5. ResolveInfo:通过解析一个与IntentFilter相对应的intent得到的信息。它部分地对应于从           AndroidManifest.xml的<intent>标签收集到的信息

            eg: 获取应用入口activity

             public static ArrayList<String> getActivities(Context context, String packageName) {

           ArrayList<String> result = new ArrayList<String>();
           Intent intent = new Intent(Intent.ACTION_MAIN, null);
           intent.setPackage(packageName);
            for (ResolveInfo info : context.getPackageManager().queryIntentActivities(intent, 0)) {
               result.add(info.activityInfo.name);
            }
           return result;
    
        }

    ps:代码复制就可以用。