LocalReport.SubreportProcessing Event


Occurs when a subreport is processed.

Namespace:   Microsoft.Reporting.WinForms
Assembly:  Microsoft.ReportViewer.WinForms (in Microsoft.ReportViewer.WinForms.dll)


public event SubreportProcessingEventHandler SubreportProcessing
event SubreportProcessingEventHandler^ SubreportProcessing {
    void add(SubreportProcessingEventHandler^ value);
    void remove(SubreportProcessingEventHandler^ value);
member SubreportProcessing : IEvent<SubreportProcessingEventHandler,
Public Event SubreportProcessing As SubreportProcessingEventHandler


The SubreportProcessing event is triggered for every instance of the subreport in the main report, and not just for each subreport definition. If a report contains multiple subreports instances from the same report definition, this event is triggered for each instance.

You must supply data for any data sources used in subreports. To do this, you must supply an event handler for the SubreportProcessing event.

You can examine values of parameters passed to the subreport by examining the Parameters property and supplying data corresponding to those parameter values.

If the main report has several subreports, you can examine the ReportPath property of the SubreportProcessingEventArgs class to determine which subreport is being processed and supply data for that subreport.

For more information about the arguments passed to this event handler, see SubreportProcessingEventArgs.


Legacy Code Example

The following code example implements a master/detail report using subreports. The code loads a sample report that contains a subreport and sets up an event handler to handle the SubreportProcessing event. The arguments passed to the SubreportProcessing event handler include an object encapsulating the subreport. The event handler adds a data source instance to this subreport before it is rendered in the ReportViewer control.

using System;
using System.Data;
using System.Windows.Forms;
using Microsoft.Reporting.WinForms;

public class Demo : Form
    private DataTable orderDetailsData = null;

    private DataTable LoadOrdersData()
        // Load data from XML file.
        DataSet dataSet = new DataSet();
        return dataSet.Tables[0];

    private DataTable LoadOrderDetailsData()
        // Load data from XML file.
        DataSet dataSet = new DataSet();
        return dataSet.Tables[0];

    void DemoSubreportProcessingEventHandler(object sender, SubreportProcessingEventArgs e)
        if (orderDetailsData == null)
            orderDetailsData = LoadOrderDetailsData();
        e.DataSources.Add(new ReportDataSource("DataSet1_OrderDetails", orderDetailsData));

    public Demo()
        this.Text = "Report Control Demo";
        this.ClientSize = new System.Drawing.Size(700, 600);

        ReportViewer reportViewer = new ReportViewer();

        // Set Processing Mode.

        reportViewer.ProcessingMode = ProcessingMode.Local;

        // Set RDL file.

        reportViewer.LocalReport.ReportPath = @"c:\Orders.rdlc";

        // Add a handler for SubreportProcessing.

        reportViewer.LocalReport.SubreportProcessing +=
                    new SubreportProcessingEventHandler(DemoSubreportProcessingEventHandler);

        // Supply a DataTable corresponding to each report dataset.

            new ReportDataSource("DataSet1_Orders", LoadOrdersData()));

        // Add the reportviewer to the form.

        reportViewer.Dock = DockStyle.Fill;

        // Process and render the report.


    public static int Main(string[] args)
        Application.Run(new Demo());
        return 0;
Option Explicit On
Imports System
Imports System.Drawing
Imports Microsoft.Reporting.WinForms

Public Class Form1
    Inherits System.Windows.Forms.Form

    Private orderDetailsData As DataTable = Nothing
    Friend WithEvents ReportViewer1 As Microsoft.Reporting.WinForms.ReportViewer

    Function LoadOrdersData() As DataTable
        ' Load
        Dim dataSet As New DataSet()
        Return dataSet.Tables(0)

    End Function

    Function LoadOrderDetailsData() As DataTable
        Dim dataSet As New DataSet()
        Return dataSet.Tables(0)
    End Function

    Public Sub DemoSubreportProcessingEventHandler(ByVal sender As Object, _
     ByVal e As SubreportProcessingEventArgs)

        If orderDetailsData Is Nothing Then
            orderDetailsData = LoadOrderDetailsData()
        End If
        e.DataSources.Add(New ReportDataSource("DataSet1_OrderDetails", orderDetailsData))
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Me.ReportViewer1 = New Microsoft.Reporting.WinForms.ReportViewer
        Me.ReportViewer1.Dock = System.Windows.Forms.DockStyle.Fill

        Me.Text = "Report Control Demo"
        Me.ClientSize = New System.Drawing.Size(700, 600)
        Me.ReportViewer1.ProcessingMode = ProcessingMode.Local
        Me.ReportViewer1.LocalReport.ReportPath = "c:\MyReports\Orders.rdlc"
        AddHandler Me.ReportViewer1.LocalReport.SubreportProcessing, AddressOf DemoSubreportProcessingEventHandler
        Me.ReportViewer1.LocalReport.DataSources.Add(New ReportDataSource("DataSet1_Orders", LoadOrdersData()))

    End Sub

End Class

See Also

LocalReport Class
Microsoft.Reporting.WinForms Namespace

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