While Mime Types are simple to add through the IIS 7.0 Configuration Manager, there are occasions where you’ll need to add them programmatically.  While there are several shell-driven options available ( powershell or the appcmd.exe utility ), IIS 7.0 includes a managed interface that is quite powerful in what it provides. 

 

As an example, I created some sample code to add a .xap ( Silverlight ) mime-type to IIS for a silent install on a client machine:

 

ServerManager serverManager = new ServerManager();
string extension = ".xap";
string mimeType = "application/x-silverlight-app";

// Pulll the config for the default website
Configuration webConfig = serverManager.GetWebConfiguration("Default Web Site");

// mime maps live in Configuration/system.webServer/staticContent 
ConfigurationSection staticContentSection = webConfig.GetSection("system.webServer/staticContent");

// let's check if the current map exists
var existingMimeMap = from mimeMaps in staticContentSection.GetCollection()
                      where mimeMaps.Attributes["fileExtension"].Value.ToString().ToLower() == extension.ToLower()
                      select mimeMaps;

if (existingMimeMap.Count() == 0)
{
    // Configuration elements must be created by the collection that will consume it
    ConfigurationElement mimeMapElement = staticContentSection.GetCollection().CreateElement("mimeMap");
    
    // set the attributes for the map
    mimeMapElement.SetAttributeValue("fileExtension", extension);
    mimeMapElement.SetAttributeValue("mimeType", mimeType);

    staticContentSection.GetCollection().Add(mimeMapElement);

    // after commit, the mimetype will be active for the current site
    serverManager.CommitChanges();
}