PublishingLayoutPage 和 WebPartPage

类继承关系：

System.Web.UI.Page

     Microsoft.SharePoint.WebPartPages.WebPartPage

          Microsoft.SharePoint.Publishing.PublishingCachablePage

               Microsoft.SharePoint.Publishing.PublishingLayoutPage

用Relector打开Microsoft.SharePoint.Publishing.dll, PublishingLayoutPage的定义如下：

[PermissionSet(SecurityAction.Demand, Name="FullTrust")]
public class PublishingLayoutPage : PublishingCachablePage
{
    // Methods
    protected override void OnPreInit(EventArgs e)
    {
        base.OnPreInit(e);
        SPContext current = SPContext.Current;
        if (current == null)
        {
            SPException exception = new SPException(Resources.GetString("ErrorInvalidSPContextCurrent"));
            ULS.SendTraceTag(ULSTagID.tag_7ob3, ULSCat.msoulscat_CMS_Publishing, ULSTraceLevel.Unexpected, "PublishingLayoutPage.OnPreInit(): Exception: SPContext.Current is null");
            throw exception;
        }
        SPWeb web = current.Web;
        this.MasterPageFile = web.CustomMasterUrl;
    }
}

 

注意最后一句：this.MasterPageFile = web.CustomMasterUrl;

由此可见，PublishingLayoutPage自动获取当前SPContent.Current.Web对象的CustomMasterUrl属性。而WebPartPage则需明确指定应用哪一种master page.