[RESOLVED] DataGridViewComboBox problem!

Hi

I have a DataGridView and am adding columns at runtime. One particular column is a ComboBox column. I have populated it but when I come to run the program, the ComboBoxes are in the relevant cells but don't drop down when you click on them! My code is below:

Code:

---

  With DataGridView1
            Dim Penalty As New DataGridViewComboBoxColumn

            With Penalty
                .Name = "Penalty"
                .HeaderText = "Penalty"
                .Width = 40
                .Visible = True
                .ReadOnly = False
                .Items.Add("1")
                .Items.Add("3")
                .Items.Add("4")
                .Items.Add("5")
                .Items.Add("6")
                .Items.Add("7")
                .Items.Add("8")
                .Items.Add("11")
            End With

            DataGridView1.Columns.Insert(6, Penalty)

        End With

---

Any help would be great! Thanks :ehh:

Me again! :D
Ok, firstly, don't nest With statements. I'm surprised that compiled, as .Name could a property of either. The following code (which is essentially the same) works on my computer:

Code:

---

                Dim Penalty As New DataGridViewComboBoxColumn With {.Name = "Penalty", .ReadOnly = False, .HeaderText = "Penalty", .Width = 40, .Visible = True}

                With Penalty.Items
                        .Add("1")
                        .Add("3")
                        .Add("4")
                        .Add("5")
                        .Add("6")
                        .Add("7")
                        .Add("8")
                        .Add("11")
                End With

                DataGridView1.Columns.Insert(6, Penalty)

---

Why hello again - thanks for the help!

Code:

---

        Dim Penalty As New DataGridViewComboBoxColumn with{.Name = "Penalty", .ReadOnly = False, .HeaderText = "Penalty", .Width = 40, .Visible = True}

---

didn't work - it had blue curly lines from the 'with' part onwards and the error said that End of statement was expected.

You could try :

Code:

---

Dim Penalty As New DataGridViewComboBoxColumn
        With Penalty : .Name = "Penalty" : .ReadOnly = False : .HeaderText = "Penalty" : .Width = 40 : .Visible = True : End With

---

You use the colon ( : ) to chain multiple statements onto one line.
Very Bad practice IMHO, though - and, doesn't address your actual problem ;)

HanneSThEGreaT

Have you any idea why the values are not showing up in my ComboBoxes?

I have been looking over it for about 45mins now with no joy! :mad:

I was curious...

Hi brjames32!

Well, I took your code exactly as it is on post#1, and it worked - just changed the column index. OK, my DataGridView was not bound to any datasource, but it works, as in the pic.

So, perhaps your problem is elsewhere ¿

Yep - I thought it should work!

Right then - I shall continue to TRY to find out what is stopping the ComboBoxes populating. The boxes are there in each row but have nothing in them.

Surely the DataGridView being populated at runtime shouldn't stop this working?

It might do if the program thinks that the column is bound at all. Are you populating manually or from a dataset?

I am populating manually at runtime so it can't be that the column thinks it's already bound.

It's a strange one ain't it?

I hooked up my dgv with a dataset, etc. And it still works :confused:

Is there any piece of code that can influence this ¿

I have attached the whole project to this reply. I can't find out what it could be! would be greatful if any of you can! The part we are discussing is in:

Code:

---

Private Sub cmdShow_Click

---

section.

Thanks a lot ;)

Without the database, it's kinda hard to run. I can spot anything wrong with that section, although with Option Strict, there a few warnings about (a couple of unused variables, which I think will get, and some functions that don't return values). Wish I could be of more help.

Oh yeah :blush: forgot about the Database. It's 4.9 meg at the moment and contains sensitive student data as it's for a school admin system.

Will see if I can strip some stuff out of it and maybe password protect it too.

:)

You could copy it, delete all the data, and type in some non-nonsensical stuff.

WOW - Access Database .rar well - it shrank from 5.9MB to 436KB!!! Also, I have attached the spreadhseets that the info is saved to - there is no problem saving though.

Anyway, here it is attached to this post . . . . .

Did anyone manage to take a look? I agree that the code is fine - tried it in another databound Datagrid of mine and it worked fine.

There's gotta be something preventing it either in the designer or in code!

I have sorted it. All I did was change the Property Readonly from True to False in the Datagridview designer and now it works!

Surely that shouldn't have been affecting the ComboBoxColumn??

That kind of makes sense - if the entire grid is read-only, then you won't be allowed to change the value of the combo, so it won't drop down.

It's doing something else strange now - when I click save it says that:

Quote:

---

Parameter @7 has no default value

---

This is the column I was having trouble with before. I have tried both selecting values for each row in the column and also setting:

Code:

---

.DefaultCellStyle.NullValue = "0"

---

but it still comes up with that error. I have also tried:

Code:

---

DataGridView1.CommitEdit

---

but still nothing!

LOL! It is always the small things that mean big headaches!
I knew it had to be something else :)

I just run your app now ( only started with it now ), and I got a Parameter @13 has no default value, in this section :

Code:

---

If ExcelYear = "10" Then
                            Dim MyExcelConnection As New System.Data.OleDb.OleDbConnection _
                            ("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\08-09\Year 10 2008-09.xls;Extended Properties=""Excel 8.0;HDR=Yes;IMEX=0""")
                            MyExcelConnection.Open()
                            With myInsertCommand
                                .CommandText = "Insert INTO [Sheet1$] ([StudentId],[StudentName],[ClassGrp],[TheDate],[Merits],[Demerits],[Penalty],[Lesson]," + _
                                        "[TeachingGrp],[Staff],[Description],[Action],[MeritType]) VALUES(@1,@2,@3,@4,@5,@6,@7,@8,@9,@10,@11,@12,@13)"
                                .CommandType = CommandType.Text
                                .Connection = MyExcelConnection
                                For Each Row As DataGridViewRow In DataGridView1.Rows
                                    For Col As Int32 = 1 To Row.Cells.Count
                                        .Parameters.Add(New OleDb.OleDbParameter("@" & Col, OleDb.OleDbType.Char)).Value = CStr(Row.Cells(Col - 1).Value)
                                    Next Col
                                    .ExecuteNonQuery()
                                    .Parameters.Clear()
                                Next
                            End With

---

Parameter 13 in this case is Merits