语法：

steam_user_installed_dlc(dlc_id);

返回： 布尔值

描述

If your game has DLC created for it, you can use this function to check and see whether the user has installed it before accessing any files associated with it. The function returns true if the player has the content installed, and false if the user does not, but note that the user must also own the DLC, so you should use the additional function of steam_user_owns_dlc to check that it is owned as well before using it.

例如：

global.Level_Max = 100;
if steam_user_owns_dlc(10354)
   {
   if steam_user_installed_dlc(10354)
      {
      global.Level_max = 200;
      }
   }

The above code will check to see if the user has bought, and installed, the DLC with the id 10354, and if so set a global variable to a different value.