ActiveReports allows you to change the data source of a report at run time based on the location of the sample database file on the user's computer.

This walkthrough illustrates how to set up a report to set a report's data source at run time.

This walkthrough is split up into the following activities:

• Adding an ActiveReport to a Visual Studio project
• Connecting the report to a data source
• Adding controls to the report to contain data
• Adding code to set the database path
• Adding code to the ReportStart event to change the data source at run time
• Viewing the report 

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

Adding an ActiveReport to your project

To add an ActiveReport to your project

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

Connecting the data source to a database

To connect the data source to a database

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".
7. Click OK to return to the report design surface.

Adding controls to contain data

To add controls to the report

• Add the following controls to the Detail section:

  Control	DataField	Name	Text/Caption	Location	OutputFormat
  TextBox	ProductID	txtProductID	Product ID	0, 0.625	(Empty string)
  TextBox	ProductName	txtProductName	Product Name	1.125, 0.0625	(Empty string)
  TextBox	UnitsInStock	txtUnitsInStock	Units In Stock	2.25, 0.0625	(Empty string)
  TextBox	UnitsOnOrder	txtUnitsOnOrder	Units On Order	3.375, 0.0625	(Empty string)
  TextBox	UnitPrice	txtUnitPrice	Unit Price	4.5, 0.0625	Currency

Adding code to set the database path

To write the code in Visual Basic

• Right-click in any section of the design window of rptModifyDS, and click on View Code to display the code view for the report. Underneath the "Imports System" at the top of the code view, add "Imports Microsoft.Win32;". Beneath "ActiveReports Designer Generated Code", type the following: "Private Function getDatabasePath() As String" and hit "Enter." This creates a function for getDatabasePath.

To write the code in C#

• Click in the gray area below rptModifyDS and click on View Code to display the code view for the report. Underneath the "using System;" at the top of the code view, add "using Microsoft.Win32;". Beneath "ActiveReports Designer Generated Code", type the following: "private string getDatabasePath()". This creates a function for getDatabasePath.

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

  ' Visual Basic
  Private Function getDatabasePath() As String
  Dim regKey As RegistryKey
  	regKey = Registry.LocalMachine
  	regKey = regKey.CreateSubKey("SOFTWARE\\Data Dynamics\\ActiveReports for .NET _
  	2.0\\SampleDB")
  	getDatabasePath = CType(regKey.GetValue(""), String)
  End Function

  //C#
  private string getDatabasePath()
  {
  	RegistryKey regKey = Registry.LocalMachine;
  	regKey = regKey.CreateSubKey("SOFTWARE\\Data Dynamics\\ActiveReports for .NET 
  		2.0\\SampleDB");
  	return (string)regKey.GetValue("");
  }

Adding code to the ReportStart event

To write the code in Visual Basic

• Right-click in any section of the design window of rptModifyDS, and click on View Code to display the code view for the report. At the top left of the code view for rptModifyDS, 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 rptModifyDS's ReportStart event. Add code to the handler to:
  • Change the data source at run time

To write the code in C#

• Click in the gray area below rptModifyDS 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 rptModifyDS's ReportStart event. Add code to the handler to:
  • Change the data source at run time

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

  ' Visual Basic
  Dim m_cnn As OleDbConnection
  Dim m_dbpath As String
  Dim m_cnnString As String
  Dim sqlString As String
  Private Sub rptModifyDS_ReportStart(ByVal sender As Object, ByVal e As System.EventArgs) _
  	Handles MyBase.ReportStart
  	m_dbpath = getDatabasePath()
  	m_cnnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + m_dbpath + "\\NWind.MDB"
  	sqlString = "SELECT * from products"	m_cnn = New OleDbConnection(m_cnnString)
  
  	If m_cnn.State = ConnectionState.Closed Then
  		m_cnn.Open()
  	End If
   
  	m_reader = m_Cmd.ExecuteReader()
  	Me.DataSource = m_reader
  End Sub

  //C#
  private static OleDbConnection m_cnn;
  private static OleDbDataReader  m_reader;
  private void rptModifyDS_ReportStart(object sender, System.EventArgs eArgs)
  {
  	string m_dbPath = getDatabasePath();
  	string m_cnnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + m_dbPath 
  		+ "\\NWind.MDB";
  	string sqlString = "SELECT * from products";
  	m_cnn = new OleDbConnection(m_cnnString);
  
  	if(m_cnn.State == ConnectionState.Closed)
  	{
  		m_cnn.Open();
  	}
   
  	m_reader = m_Cmd.ExecuteReader();
  	this.DataSource = m_reader;
  }

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

 

 

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