How To Dynamically Populate a Data Report in Visual Basic

Summary

This article explains how to create a report without binding the report to any data at design time. This allows you to generate a report without knowing the column names within the Data Source.

More Information

When using the Data Report, textboxes must be bound to an ADO recordset. In some situations it is necessary to generate this data report at runtime without knowing the column names at design time. To do this you must first have a data report included in your project with the correct number of controls needed to display the data being retrieved. Then open an ADO recordset and loop through this recordset populating the controls that were placed on the data report. The following code demonstrates how to accomplish this.

Sample Code

  1. Start a new Visual Basic Standard EXE project. Form1 is added by default.
  2. From the Project menu, click References, and select the Microsoft ActiveX Data Objects.
  3. From the Project menu select "Add Data Report". If there is no option for a Data Report then you will need to choose Components from the Project and a dialog box is displayed. Click on the Designers tab and add a reference to the Data Report.
  4. In the Data Report properties change the Data Report name to DR.
  5. Place two report Labels and two report Textboxes in the Detail Section of the report.
  6. Place a command button on Form1 named command1.
  7. Place the following code into Form1.
       Dim cn As New ADODB.Connection
    Dim rs As New ADODB.Recordset
    Dim cmd As New ADODB.Command

    Private Sub Command1_Click()
    Dim q As Integer
    Dim intCtrl As Integer
    Dim x As Integer
    Dim z As Integer
    x = 0
    q = 0
    z = 0

    With DR
    .Hide
    Set .DataSource = rs
    .DataMember = ""
    With .Sections("Section1").Controls
    For intCtrl = 1 To .Count
    If TypeOf .Item(intCtrl) Is RptLabel Then
    .Item(intCtrl).Caption = rs.Fields(q).Name & " :"
    q = q + 1
    End If
    If TypeOf .Item(intCtrl) Is RptTextBox Then
    .Item(intCtrl).DataMember = ""
    .Item(intCtrl).DataField = rs(z).Name
    z = z + 1
    End If
    Next intCtrl
    End With
    .Refresh
    .Show
    End With
    End Sub

    Private Sub Form_Load()

    Command1.Caption = "Show Report"

    cn.Open "Provider=Microsoft.Jet.OLEDB.4.0;" & _
    "Data Source=C:\Program Files\Microsoft Visual Studio\VB98\Nwind.mdb;"

    With cmd
    .ActiveConnection = cn
    .CommandType = adCmdText
    .CommandText = "Select FirstName, Lastname from Employees"
    .Execute
    End With

    With rs
    .ActiveConnection = cn
    .CursorLocation = adUseClient
    .Open cmd
    End With

    End Sub
  8. Change the Data Source Property in the connect string to the path to your Northwind MDB.
  9. Save and Run the Project. You should see a Data Report created with the information returned from the Northwind database.
(c) Microsoft Corporation 1999, All Rights Reserved. Contributions by Terrell D. Andrews, Microsoft Corporation.

Propriétés

ID d'article : 240019 - Dernière mise à jour : 4 août 2008 - Révision : 1

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