Parameters can be used with subreports to connect the subreport to the parent report. By setting a parameter for the field that links the parent report to the subreport, the parent report can pass the information to the subreport through the parameters.

Note   Subreports will not render PageHeader/Footer sections.

This walkthrough illustrates how to set up a subreport using parameters to link the parent report to the subreport.

This walkthrough is split up into the following activities:

• Adding two ActiveReports to a Visual Studio project
• Connecting the parent report to a data source
• Connecting the child report to a data source using parameters
• Adding controls to display the data
• Adding the code needed to link the subreport to the current record's supplierID
• Adding the code to set the subreport's ShowParametersUI property to False
• Viewing the report 

To complete the walkthrough, you must have access to the NorthWind database (NWind.mdb).

When you have finished this walkthrough, you will have a report that looks similar to the following.

Adding two ActiveReports to a Visual Studio project

To add two ActiveReports to a Visual Studio project

1. Open a new project in Visual Studio.
2. Click on Project > Add New Item.
3. Select ActiveReports file and rename the file rptParent.
4. Click Open.
5. Click on Project > Add New Item.
6. Select ActiveReports file and rename the file rptChild.
7. Click Open.

Connecting the parent report to a data source

To connect the parent report to a data source

1. Click on the yellow report DataSource icon in the Detail section. This brings up the report DataSource dialog box.
2. Click on Build...
3. Select Microsoft Jet 4.0 OLE DB Provider and click Next >>
4. Click on the ellipsis to browse for the access path to NWind.mdb. Click Open once you have selected the appropriate access path.
5. Click OK to continue.
6. In the Query field, type "Select * from suppliers order by country".
7. Click OK to return to the report design surface.

Connecting the child report to a data source using parameters

To connect the child report to a data source

1. Click on the yellow report DataSource icon in the Detail section. This brings up the report DataSource dialog box.
2. Click on Build...
3. Select Microsoft Jet 4.0 OLE DB Provider and click Next >>
4. Click on the ellipsis to browse for the access path to NWind.mdb. Click Open once you have selected the appropriate access path.
5. Click OK to continue.
6. In the Query field, type "SELECT * FROM products INNER JOIN categories ON products.categoryid = categories.categoryid WHERE products.supplierID =<%SupplierID%>".
7. Click OK to return to the report design surface.

Adding controls to display the data

To add controls to the reports

1. Add a GroupHeader/Footer section to rptParent.
2. Make the following changes to the group header:
   • Change the name to ghSuppliers
   • Change the DataField property to Country
3. Add the following controls to rptParent, naming them as indicated:

    

   Control	DataField	Name	Text/Caption	Section	Location
   TextBox	Country	txtCountry	Country	GroupHeader	0, 0
   TextBox	CompanyName	txtCompanyName	Company Name	Detail	0.0625, 0.0625
   TextBox	ContactName	txtContactName	Contact Name	Detail	2.312, 0.0625
   TextBox	Phone	txtPhone	Phone	Detail	4.562, 0.0625
   Subreport	(Empty string)	Subreport1	(Empty string)	Detail	0.0625, 0.312

    

4. Add a GroupHeader/Footer section to rptChild.
5. Make the following changes to the group header:
   • Change the name to ghProducts
   • Change the DataField property to CategoryName
6. Add the following controls to rptChild, naming them as indicated:

    

   Control	DataField	Name	Text/Caption	Section	Location
   TextBox	CategoryName	txtCategoryName	Category Name	GroupHeader	0.0625, 0.0625
   TextBox	ProductName	txtProductName	Product Name	Detail	0.0625, 0.0625

Adding the code needed to link the subreport to the current record's supplierID

To write the code in Visual Basic

• Right-click in any section of the design window of rptParent, and click on View code to display the code view for the report. At the top left of the code view for rptParent, click the drop-down arrow and select Detail. At the top right of the code window, click the drop-down arrow and select Format. This creates an event-handling method for rptParent's Detail_Format event. Add code to the handler to:
  • Link the subreport to the current record's supplierID

To write the code in C#

• Click on the Detail section of rptParent to select the section. Click on the events icon in the Properties window to display available events for the report. Double-click Format. This creates an event-handling method for rptParent's Detail_Format event. Add code to the handler to:
  • Link the subreport to the current record's supplierID

  The following example shows what the code for the method looks like.

  ' Visual Basic
  Private Sub Detail_Format(ByVal sender As Object, ByVal e As System.EventArgs) Handles _
  	Detail.Format
          Dim rpt As New rptChild()
          Me.SubReport1.Report = rpt
  End Sub
          

  //C#
  private void Detail_Format(object sender, System.EventArgs eArgs)
  {
       rptChild rpt = new rptChild();
        this.SubReport1.Report = rpt;
  }
          

Adding the code to set the subreport's ShowParametersUI property to False

To write the code in Visual Basic

• Right-click in any section of the design surface of rptChild, and click on View code to display the code view for the report. At the top left of the code view for rptChild, click the drop-down arrow and select (Base Class Events). At the top right of the code window, click the drop-down arrow and select ReportStart. This creates an event-handling method for the rptChild's ReportStart event. Add code to the handler to:
  • Set the subreport's ShowParametersUI property to False

To write the code in C#

• Click in the gray area below rptChild to select the report. Click on the events icon in the Properties window to display available events for the report. Double-click ReportStart. This creates an event-handling method for rptChild's ReportStart event. Add code to the handler to:
  • Set the subreport's ShowParametersUI property to False

  The following example shows what the code for the method looks like.

  ' Visual Basic
  Private Sub rptChild_ReportStart(ByVal sender As Object, ByVal e As System.EventArgs) _
  	Handles MyBase.ReportStart
          Me.ShowParameterUI = False
  End Sub
          

  //C#
  private void rptChild_ReportStart(object sender, System.EventArgs eArgs)
  {
         this.ShowParameterUI = false;
  }
          

Viewing the report

To view the report

1. Add the ActiveReports viewer control to a Windows Form.
2. Add the code needed to set the viewer document equal to the report document. See Using the ActiveReports WinForm Viewer for help.

Samples | Walkthroughs | Parameters

 

 

---

Copyright © 2004-2005 Data Dynamics, Ltd. All rights reserved.