Windows Forms FAQ resources

5. Windows Forms Datagrid

5.64 How can I specially color only the currentcell of my readonly datagrid?

You can use the first technique listed in this FAQ: How do I color an individual cell depending upon its value or some external method?

The idea is to derive a custom columnstyle. override its Paint method to specially color the background of the currentcell. Also, override the Edit to avoid the current cell becoming active. Below is a code snippet showing how you can do this. You can also download samples(C#, VB).

Public Class DataGridColoredTextBoxColumn

Inherits DataGridTextBoxColumn

Private column As Integer ' column where this columnstyle is located...

Public Sub New()

column = -2

End Sub

Protected Overloads Overrides Sub Paint(ByVal g As Graphics, ByVal bounds As Rectangle, ByVal source As CurrencyManager, ByVal rowNum As Integer, ByVal backBrush As Brush, ByVal foreBrush As Brush, ByVal alignToRight As Boolean)

Try

Dim grid As DataGrid = Me.DataGridTableStyle.DataGrid

'first time set the column properly

If column = -2 Then

Dim i As Integer

i = Me.DataGridTableStyle.GridColumnStyles.IndexOf(Me)

If i > -1 Then

column = i

End If

If grid.CurrentRowIndex = rowNum And grid.CurrentCell.ColumnNumber = column Then

backBrush = New LinearGradientBrush(bounds, Color.FromArgb(255, 200, 200), Color.FromArgb(128, 20, 20), LinearGradientMode.BackwardDiagonal)

foreBrush = New SolidBrush(Color.White)

End If

Catch ex As Exception

' empty catch

Finally

' make sure the base class gets called to do the drawing with

' the possibly changed brushes

MyBase.Paint(g, bounds, source, rowNum, backBrush, foreBrush, alignToRight)

End Try

End Sub

Protected Overloads Overrides Sub Edit(ByVal source As System.Windows.Forms.CurrencyManager, ByVal rowNum As Integer, ByVal bounds As System.Drawing.Rectangle, ByVal [readOnly] As Boolean, ByVal instantText As String, ByVal cellIsVisible As Boolean)

'do nothiing... don't call the basecalss

End Sub

End Class