尝试：

Try:

rvSiteMapping.ServerReport.ReportServerUrl = new Uri("http://abcd1234/ReportServer");
rvSiteMapping.ServerReport.ReportPath = String.Format("/{0}/{1}", reportFolder, Request["ReportName"]);

ReportServerUrl 是报告服务配置中的Web服务URL。它不应包含文件夹或报告名称。

The ReportServerUrl is the "Web Service URL" in the reporting services configuration. It should not include the folder or report names.