利用reporting services扩展开发报表，实现group的展开折叠功能

来源：互联网发布：网络电视机排行榜编辑：程序博客网时间：2024/05/22 12:07

该功能的实现需要借助于reporting services的cache功能。当用户成功运行一个report后，该report就会被存储在server的cache中，直到用户的session结束才被自动清除。

1. 第一次运行report时，加载报表定义并获得该report的ExecutionID，并将其存储在session中

            //load report definition
            execInfo = res.LoadReportDefinition(rptDefinition, out warnings);
            //store ExecutionID for later requests
            Session[strExecutionID] = execInfo.ExecutionID;

2. 当点击报表上的加号或减号图标去展开折叠一个group时，将ToggleItemId并传给服务器。

a. 服务器用此前的ExecutionID获得在Cache的报表。

res.ExecutionHeaderValue.ExecutionID = (String)Session[strExecutionID];

b. 调用ToggleItem方法，告诉服务器要展开或折叠报表的哪个group。

resToggle = res.ToggleItem(strToggleItem);
c. 最后再调用Render方法并将报表输出到web页面

具体代码如下：

       String strDevInfo = (strFormat == "HTML4.0" ? "<DeviceInfo><Toolbar>True</Toolbar><Section>0</Section><HTMLFragment>False</HTMLFragment></DeviceInfo>" : "");
        String strExtension;
        String strEncoding;
        String strMimeType;
        Warning[] warnings = null;
        String[] strStreamIDs = null;
        ExecutionInfo execInfo = new ExecutionInfo();
        ExecutionHeader execHeader = new ExecutionHeader();

        ReportExecutionService res = new ReportExecutionService();
        res.Credentials = System.Net.CredentialCache.DefaultCredentials;
        res.Url = strRESUrl;
        res.Timeout = System.Threading.Timeout.Infinite;
        res.ExecutionHeaderValue = execHeader;
        if ("" != strToggleItem && null != Session[strExecutionID])
        {
            res.ExecutionHeaderValue.ExecutionID = (String)Session[strExecutionID];
        }
        else
        {
            //load report definition
            execInfo = res.LoadReportDefinition(rptDefinition, out warnings);
            //store ExecutionID for later requests
            Session[strExecutionID] = execInfo.ExecutionID;
        }
        Byte[] rptRefined = null;
        Boolean resToggle = true;
        try
        {
            if ("" != strToggleItem && null != Session[strExecutionID])
            {
                resToggle = res.ToggleItem(strToggleItem);
            }
            //execute the report
            rptRefined = res.Render(strFormat, strDevInfo, out strExtension, out strMimeType, out strEncoding, out warnings, out strStreamIDs);

            //flush any pending response
            Response.Clear();
            //set the HTTP headers for a HTML response
            HttpContext.Current.Response.ClearHeaders();
            HttpContext.Current.Response.ClearContent();
            switch (strFormat)
            {
                case "PDF": HttpContext.Current.Response.ContentType = "application/pdf"; break;
                case "EXCEL": HttpContext.Current.Response.ContentType = "application/vnd.ms-excel"; break;
                case "Word": HttpContext.Current.Response.ContentType = "application/msword"; break;
                default: HttpContext.Current.Response.ContentType = "text/html"; break;
            }
            HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.UTF8;
            //send the bytes array containing the report as a binary response
            HttpContext.Current.Response.BinaryWrite(rptRefined);
            HttpContext.Current.Response.End();
        }
        catch (Exception ex)
        {
            if (ex.Message != "Thread was being aborted.")
            {
                HttpContext.Current.Response.ClearHeaders();
                HttpContext.Current.Response.ClearContent();
                HttpContext.Current.Response.ContentType = "text/html";
                HttpContext.Current.Response.Write("<html><body><h1>Error</h1><br><br>" + ex.Message + "</body></html>");
            }
        }
        res.Dispose();
        res = null;

附上获得ToggleItemID的js代码：
function js_showReport(evt, strId) {
    var rptDiv = document.getElementById(strId);
    rptDiv.getElementsByTagName("div")[0].style.display = "none";
    rptDiv.getElementsByTagName("iframe")[0].style.display = "block";