登录Google开发者控制台： https://play.google.com/apps/publish

编辑：它位于游戏服务标签

I created android application and hosted it on google play, but suddenly I deleted my project in Eclipse (from disk too) and now I am restoring some files from backup but I don't have old app_id in res/values/strings.xml

how can I get app_id from play services or .apk or keystore because I need it for Google API integration

 <meta-data android:name="com.google.android.gms.games.APP_ID"
            android:value="@string/app_id" />

Sign in to the google developers console here: https://play.google.com/apps/publish

You should be able to find it under your app.

EDIT: It's in the Games Services tab