Data Validation Sample

Visual Basic Samples

This sample demonstrates the Dataset Designer and uses the PropertyChanged events to validate user input.

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Security Note:
This sample code is intended to illustrate a concept, and it shows only the code that is relevant to that concept. It may not meet the security requirements for a specific environment, and it should not be used exactly as shown. We recommend that you add security and error-handling code to make your projects more secure and robust. Microsoft provides this sample code "AS IS" with no warranties.

To run this sample

Press F5.

Requirements

This sample requires the Northwind sample database. For more information, see How to: Install and Troubleshoot Database Components for Samples.

Demonstrates

This sample demonstrates the data validation features available in the Visual Studio designers. Two arbitrary and fictitious rules are used to validate the data. Code is added using the Dataset Designer. Double-clicking a column name creates the event for the column change. Double-clicking the field list creates the event for the row change. In those event handlers, code is added to validate the proposed values:

Private Sub EmployeeDataTable_BirthDateChanging( _
    ByVal sender As EmployeeDataTable, _
    ByVal e As BirthDateChangeEventArg) Handles Me.BirthDateChanging

    Dim minimumAgeDate As New DateTime(DateTime.Now().Year - 18, _
        DateTime.Now().Month, DateTime.Now().Day)
    If e.ProposedValue > minimumAgeDate Then
        e.Row.SetColumnError(e.BirthDateColumn, _
            "Employees must be at least 18 years of age.")
    Else
        e.Row.SetColumnError(e.BirthDateColumn, "")
    End If
End Sub

Private Sub EmployeesDataTable_EmployeesRowChanging( _
    ByVal sender As System.Object, ByVal e As _
    EmployeesRowChangeEvent) Handles Me.EmployeesRowChanging
    If (e.Row.BirthDate = e.Row.HireDate) Then
        e.Row.RowError = e.Row.RowError & _
            "Birth date and hire date are the same."
    Else
        e.Row.ClearErrors()
    End If
End Sub

When row and column errors are defined, the DataGridView control displays a warning icon. For row errors, the icon is displayed to the left of the row. For column errors, the icon is displayed in the cell.

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