Making DataGridView rows a certain color based on a column value

by

There are a couple of issues with your code.

First, you are handling the CellFormatting event but you are iterating every row to set the backcolor. That event is meant for you to do something to a single, specific cell, the one in question is indicated in the event args: e.RowIndex and e.ColumnIndex. Using a loop, you are acting on many more rows than needed and doing so over and over.

Second, VB has data types. Int32 is one type, String is another, and Object is yet another. You need to convert one type to the other type before you compare. LaptopGrid.Rows(r).Cells(c).Value returns Object (since a cell can literally hold anything), so to compare to 1 you need to convert it to integer.

Finally, you may not want the CellFormatting event for this. If the cell in question is not on screen, the event wont fire (perhaps the user resized the columns). RowPrePaint on the other hand will fire when the row scrolls into view.

Private Sub dgv1_RowPrePaint(sender As Object, 
                   e As DataGridViewRowPrePaintEventArgs) Handles dgv1.RowPrePaint

    ' dont do the NewRow
    If e.RowIndex < 0 OrElse dgv1.Rows(e.RowIndex).IsNewRow Then Return

    ' convert to int32, then compare
    ' act on just this row - e.RowIndex
    If Convert.ToInt32(dgv1.Rows(e.RowIndex).Cells(3).Value) > 3 Then
        dgv1.Rows(e.RowIndex).DefaultCellStyle.BackColor = Color.LemonChiffon
    Else
        dgv1.Rows(e.RowIndex).DefaultCellStyle.BackColor = Color.MistyRose
    End If

End Sub

enter image description here

If the user can edit that cell value, you will want to update the back color accordingly.

More Related Contents:

  1. Searching values via a datagridview
  2. How to print datagridview table with its header in vb.net?
  3. How to loop through all the properties of a class?
  4. Case insensitive string compare in LINQ-to-SQL
  5. Does XSLT have a Split() function?
  6. Pick unique Random numbers
  7. Update primary key value using entity framework
  8. Can I set Option Explicit and Option Strict on a Project/Solution level?
  9. Controlling Application’s Volume: By Process-ID
  10. Is it necessary to add a @ in front of an SqlParameter name?
  11. Accessing imgUr thru OAuth (uploading to user account)
  12. How do I validate email address formatting with the .NET Framework?
  13. Does this code prevent SQL injection?
  14. Option Strict On and .NET for VB6 programmers
  15. RestSharp serialization to JSON, object is not using SerializeAs attribute as expected
  16. DataGridView: How can I make the enter key add a new line instead of changing the current cell?
  17. How to improve painting performance of DataGridView?
  18. How to draw a signature and save it to disc as a Bitmap?
  19. How to convert date format in vb.net?
  20. Redirect Trace output to Console
  21. How to make a Windows Forms .NET application display as tray icon?
  22. LinqToSql declare and instantiate DataContext best practice?
  23. Assigning a value to ComboBox Items
  24. Are nested Try/Catch blocks a bad idea?
  25. Shadows vs Overloads in VB.NET
  26. Custom button captions in .NET messagebox?
  27. .NET — Textbox control – wait till user is done typing
  28. How to post a file via HTTP post in vb.net
  29. How to securely store a connection string in a WinForms application?
  30. VB.NET Excel Program Leaves EXCEL.EXE floating after completion

Leave a Comment