android通过apk包得到apk包信息

　　　　//安装包路径  
        String weicharFilePath="sdcard/weichar.apk";
        PackageManager pm = getPackageManager();    
        PackageInfo info = pm.getPackageArchiveInfo(weicharFilePath, PackageManager.GET_ACTIVITIES);    
        if(info != null){    
            ApplicationInfo appInfo = info.applicationInfo;    
            String appName = pm.getApplicationLabel(appInfo).toString(); 
          //得到安装包名称  
            String packageName = appInfo.packageName; 
          //得到版本信息    
            String version=info.versionName;
            //得到图标信息  
            Drawable icon = pm.getApplicationIcon(appInfo);
        }