Determine If Changed Event Occurred from User Input Or Not

Question

In C#, the Changed event for a control (say, a numericupdown) gets fired whether the value was change directly by the user or if it was changed programatically as the result

Answer 1

1. Inherit NumericUpDown Class
2. Create a flag for determine value changed programmatically, or changed by GUI
3. Overload Value Property to set above flag

Here is my solution in VB .NET

    Private m_blnIsValueChangedByGui As Boolean = True

    Public Property IsValueChangedByGui() As Boolean
        Get
            Return m_blnIsValueChangedByGui
        End Get
        Set(ByVal value As Boolean)
            m_blnIsValueChangedByGui = value
        End Set
    End Property

    Public Shadows Property Value() As Decimal
        Get
            Return MyBase.Value
        End Get
        Set(ByVal value As Decimal)
            IsValueChangedByGui = False

            If (value > Me.Maximum) Then
                MyBase.Value = Me.Maximum
            ElseIf (value < Me.Minimum) Then
                MyBase.Value = Me.Minimum
            Else
                MyBase.Value = value
            End If

            IsValueChangedByGui = True
        End Set
    End Property