Create a new Wiki Page

The code below adds a new wiki page and then inserts a web part into the new page’s rich text editor

SPList pagesList = web.Lists["Pages"];

SPFolder rootFolder = pagesList.RootFolder;

SPFileCollection fileCollection = rootFolder.Files;

string pageUrl = rootFolder.ServerRelativeUrl + "/MyNewPage.aspx";

//Create the page
SPFile newFile = fileCollection.Add(pageUrl, SPTemplateFileType.WikiPage);

//Checkout and add custom web part to the newly created page
newFile.CheckOut();

//Use a new Guid as the web part id
Guid storageKey = Guid.NewGuid();

string wpId = String.Format("g_{0}", storageKey.ToString().Replace('-', '_'));

//Get web part manager
using (SPLimitedWebPartManager manager = newFile.GetLimitedWebPartManager(System.Web.UI.WebControls.WebParts.PersonalizationScope.Shared))

{

//Initialize the web part and insert it into 'wpz' web part zone.
//Web part zone is hidden in Rich text editor and its name is fixed ('wpz')

MyWebPart webPart = new MyWebPart();

webPart.ID = wpId;

webPart.Title = "My New Page";

manager.AddWebPart(webPart, "wpz", 0);

string content = String.Format(CultureInfo.InvariantCulture
, "<div class=\"ms-rtestate-read ms-rte-wpbox\" contentEditable=\"false\"><div class=\"ms-rtestate-read {0}\" id=\"div_{0}\"></div><div style='display:none' id=\"vid_{0}\"></div></div>"

, new object[] { storageKey.ToString("D") });

SPListItem item = newFile.Item;

item["WikiField"] = content;

item.Update();

}
newFile.CheckIn(string.Empty);

Hope that helps 🙂