Create Custom DataGridView Cell from UserControl

Well, the title pretty much says it all. I have a user control that is a a collection of six label controls. three are used as visual color indicators, and the other three are used as the corresponding value for each color indicator. (It's sort of like a legend key on a chart or map.) I have created a custom class to store the three values, and the associated methods to interact with the values. (I can probably use a structure instead of a class, but right now, I don't want to discuss that.) My problem, is that I want to show my user control inside a cell of a DataGridView. I've looked at the examples that create a MaskedTextBox DataGridViewCell, but I can't seem to get it to work. Here is what I have:

The Column class:

Code:

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Public Class DataGridViewResultsColumn
    Inherits DataGridViewColumn

    Public Sub New()
        MyBase.New(New DataGridViewResultsCell())
    End Sub

    Public Overrides Property CellTemplate() As System.Windows.Forms.DataGridViewCell
        Get
            Return MyBase.CellTemplate
        End Get
        Set(ByVal value As System.Windows.Forms.DataGridViewCell)
            ' ensure that the cell used for the template is a ResultsCell
            If (value IsNot Nothing) AndAlso _
                Not value.GetType().IsAssignableFrom(GetType(DataGridViewResultsCell)) Then
                Throw New InvalidCastException("Must be a DataGridViewResultsCell")
            End If

            MyBase.CellTemplate = value
        End Set
    End Property
End Class

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The Cell class:

Code:

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Public Class DataGridViewResultsCell
    Inherits DataGridViewTextBoxCell

    Public Overrides Sub InitializeEditingControl(ByVal rowIndex As Integer, ByVal initialFormattedValue As Object, ByVal dataGridViewCellStyle As System.Windows.Forms.DataGridViewCellStyle)
        ' set the value of the editing control to the current cell value
        MyBase.InitializeEditingControl(rowIndex, initialFormattedValue, dataGridViewCellStyle)

        Dim ctl As ResultsEditingControl = CType(DataGridView.EditingControl, ResultsEditingControl)

        ' use default row value when value property is null
        If Not (Me.Value Is Nothing) Then
            ctl.CovRes = CType(Me.Value, CoverageResult)
        End If
    End Sub

    Public Overrides ReadOnly Property EditType() As System.Type
        Get
            Return GetType(ResultsEditingControl)
        End Get
    End Property

    Public Overrides ReadOnly Property ValueType() As System.Type
        Get
            Return GetType(CoverageResult)
        End Get
    End Property

    Public Overrides ReadOnly Property DefaultNewRowValue() As Object
        Get
            Return New CoverageResult(0, 0)
        End Get
    End Property
End Class

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I read somewhere that I need to create an editing control class to wrap my user control. I've listed that below, but I have two issues with that:

1. The data contained in my UserControl is readonly. Do I really need an editing control class?
2. I don't know what to code for most of the methods of the editing control class.

Code:

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Public Class ResultsEditingControl
    Inherits ctlCoverageResult
    Implements IDataGridViewEditingControl

    Public Sub ApplyCellStyleToEditingControl(ByVal dataGridViewCellStyle As System.Windows.Forms.DataGridViewCellStyle) Implements System.Windows.Forms.IDataGridViewEditingControl.ApplyCellStyleToEditingControl
        ' Don't know what should go here.
    End Sub

    Private _DataGridView As DataGridView
    Public Property EditingControlDataGridView() As System.Windows.Forms.DataGridView Implements System.Windows.Forms.IDataGridViewEditingControl.EditingControlDataGridView
        Get
            Return _DataGridView
        End Get
        Set(ByVal value As System.Windows.Forms.DataGridView)
            _DataGridView = value
        End Set
    End Property

    Public Property EditingControlFormattedValue() As Object Implements System.Windows.Forms.IDataGridViewEditingControl.EditingControlFormattedValue
        Get
            ' Don't know what should go here.
        End Get
        Set(ByVal value As Object)
            ' Don't know what should go here.
        End Set
    End Property

    Public Property EditingControlRowIndex() As Integer Implements System.Windows.Forms.IDataGridViewEditingControl.EditingControlRowIndex
        Get
            ' Don't know what should go here.
        End Get
        Set(ByVal value As Integer)
            ' Don't know what should go here.
        End Set
    End Property

    Public Property EditingControlValueChanged() As Boolean Implements System.Windows.Forms.IDataGridViewEditingControl.EditingControlValueChanged
        Get
            ' Don't know what should go here.
        End Get
        Set(ByVal value As Boolean)
            ' Don't know what should go here.
        End Set
    End Property

    Public Function EditingControlWantsInputKey(ByVal keyData As System.Windows.Forms.Keys, ByVal dataGridViewWantsInputKey As Boolean) As Boolean Implements System.Windows.Forms.IDataGridViewEditingControl.EditingControlWantsInputKey
        ' Don't know what should go here.
    End Function

    Public ReadOnly Property EditingPanelCursor() As System.Windows.Forms.Cursor Implements System.Windows.Forms.IDataGridViewEditingControl.EditingPanelCursor
        Get
            Return MyBase.Cursor
        End Get
    End Property

    Public Function GetEditingControlFormattedValue(ByVal context As System.Windows.Forms.DataGridViewDataErrorContexts) As Object Implements System.Windows.Forms.IDataGridViewEditingControl.GetEditingControlFormattedValue
        ' Don't know what should go here.
    End Function

    Public Sub PrepareEditingControlForEdit(ByVal selectAll As Boolean) Implements System.Windows.Forms.IDataGridViewEditingControl.PrepareEditingControlForEdit
        ' Don't know what should go here.
    End Sub

    Public ReadOnly Property RepositionEditingControlOnValueChange() As Boolean Implements System.Windows.Forms.IDataGridViewEditingControl.RepositionEditingControlOnValueChange
        Get
            ' Don't know what should go here.
        End Get
    End Property
End Class

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After all of this, the DataGridView only displays the name of the class that I created to hold the data, i.e., [ProgramName].[ClassName]

Do I need to override the Paint method for the DataGridViewCell? If so, how do I get the cell (row and column) to resize to correctly fit my UserControl?

Thanks.

Did you ever get this to work?

Justin

No, I was not able to get this working. I ended up using a TableLayoutPanel and mimicking the visual style of a DataGridView. For me, everything was ReadOnly, so I didn't have to emulate the functionality of the DataGridView.

Yeah I was trying to make a datagridview column that hosted my custom checkbox control but never got it to work. So I just used the same checked and unchecked image I had in an image column and switched the image on click.

Thanks for the reply,

Justin