How to change master page on the fly in ASP.NET

In web form page, add: 

protected void Page_PreInit(object sender, EventArgs e) 

{ 

    this.Page.MasterPageFile = "~/name.master";

}

How to get current page name in master page?

public string GetCurrentPageName() 
{ 
    string Path = System.Web.HttpContext.Current.Request.Url.AbsolutePath; 
    System.IO.FileInfo fInfo = new System.IO.FileInfo(Path); 
    return fInfo.Name; 
}