设置本地报告的数据源 - .NET和报告查看器

Question

我创建了一个自定义控件(带有报表查看器的Windows窗体).我有以下代码来加载本地报告:

包含在CustomReportViewer类中

//Load local report 
this.reportViewer1.ProcessingMode = ProcessingMode.Local;         
//enable loading of external images          
this.reportViewer1.LocalReport.EnableExternalImages = true;
//pass the report to the viewer
using (FileStream stream = new FileStream(filename, FileMode.Open))
{
   this.reportViewer1.LocalReport.LoadReportDefinition(stream);
}

我用这个叫:

CustomReportViewer reportViewer = new CustomReportViewer();

这工作正常,出现一个包含报表查看器控件的窗体,但我收到以下消息:

A data source instance has not been supplied for the data source "ReportData"

我不完全确定如何设置数据源？我需要的数据存储在远程数据库中...我需要做什么才能设置此连接？

Answer 1

您需要创建一个ReportDataSource,并设置其Value属性 - 例如DataTable,IEnumerables是受支持的源

作为示例,假设存在一个返回DataSet的方法,只需一个DataTable匹配报表所需的列:

DataSet ds = SomeMethodToRetrieveDataSet(); // e.g. via DataAdapter
// If your report needs parameters, they need to be set ...
ReportParameter[] parameters = new ReportParameter[...];

ReportDataSource reportDataSource = new ReportDataSource();
// Must match the DataSource in the RDLC
reportDataSource.Name = "ReportData"; 
reportDataSource.Value = ds.Tables[0];

// Add any parameters to the collection
reportViewer1.LocalReport.SetParameters(parameters); 
reportViewer1.LocalReport.DataSources.Add(reportDataSource);
reportViewer1.DataBind();

请注意,将RDLC嵌入到程序集中通常更容易,而不必保留单独的RDLC文件.通过Build Action在RDLC上选择as 来执行此操作Embedded Resource,然后您可以设置ReportEmbeddedResource属性:

reportViewer1.LocalReport.ReportEmbeddedResource = 
                         "MyOrganisation.MyAssembly.NameSpace.MyReportName.rdlc";

请注意,资源字符串必须包含资源的完全限定名称(包括Assembly).

Answer 2

对我来说,关键在于StuartLC如上所述......进一步说明当他说"必须匹配RDLC中的DataSource"时......它实际上证明是"DataSetName"元素值: <DataSetName>DataSet1</DataSetName>

我一遍又一遍地因为它被称为"DataSource"所以我继续使用DataSource元素名称,但显然在rdl和rdlc文件中这确实表示DataSetName.因此,请记住这一点是从上面借用我自己的Stuart借来的代码.请注意DataSetName元素值:

        using (SqlConnection sqlConn = new SqlConnection(rvConnection))
        using (SqlDataAdapter da = new SqlDataAdapter(rvSQL, rvConnection))
        {
            DataSet ds = new DataSet();
            da.Fill(ds);
            DataTable dt = ds.Tables[0];

            this.reportViewer1.Reset();
            this.reportViewer1.ProcessingMode = ProcessingMode.Local; 
            this.reportViewer1.LocalReport.ReportPath = AppDomain.CurrentDomain.BaseDirectory + "ssrsExport.rdlc";
            ReportDataSource reportDataSource = new ReportDataSource();
            // Must match the DataSet in the RDLC
            reportDataSource.Name = "DataSet1"; 
            reportDataSource.Value = ds.Tables[0];
            this.reportViewer1.LocalReport.DataSources.Add(reportDataSource);   
            this.reportViewer1.RefreshReport();
        }