[RESOLVED] Setting Selected Index on DataGridView Combobox

I can't seem to set the selected index or selected value of a DataGridView combobox when loading data from a database. My DGV has two combobox columns which are bound to datatables. The DGV itself is not bound initially. After adding a row, I select a value from each combobox which then populates the rest of the cells in the row. I'm using the EditingControlShowing event to add an eventhandler to catch the SelectedIndexChange of the combo boxes. This all works as needed. My issue comes when populating the DGV with saved data, I need to add the rows and set the selected index and/or selected value of each combo box. I've searched through various forums and articles for the last week with no luck.

I'm using VS2008 sp1, .NET 3.5 sp1 and SQL 2005 sp2 Express.

I'm fairly new to .NET and winforms development, coming mostly from a web background so any help is greatly appreciated.

Please let me know if I need to give more details or post any code.

Thanks

Welcome to the forums HatMaster! sorry for the extremely delayed reply!

When you add the row, you should be able to just access the cell which is the ComboBoxCell and set the value property. Here's a quick example which assumes that column 0 is the combo box:

Code:

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'First, get the cell as a useful object
'You'll need to know the index of the new row
Dim CBox as DataGridViewComboBoxCell = CType(DGV.Rows(NewRowIndex).Cell(0), DataGridViewComboBoxCell)
Dim CCol as DataGridViewComboBoxColumn = CType(DGV.Columns(0)), DataGridViewComboBoxColumn)

CBox.Value = CCol.Items(CCol.Items.Count - 1)

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This sets the value of the combobox in column 0 of row NewRowIndex to the last value from the list defined in the column settings for column 0

Thanks javajawa!!!

It worked. I thought I had already tried something similar but your example worked perfectly. I appreciate the help!

Quote:

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Originally Posted by javajawa

Welcome to the forums HatMaster! sorry for the extremely delayed reply!

When you add the row, you should be able to just access the cell which is the ComboBoxCell and set the value property. Here's a quick example which assumes that column 0 is the combo box:

Code:

---

'First, get the cell as a useful object
'You'll need to know the index of the new row
Dim CBox as DataGridViewComboBoxCell = CType(DGV.Rows(NewRowIndex).Cell(0), DataGridViewComboBoxCell)
Dim CCol as DataGridViewComboBoxColumn = CType(DGV.Columns(0)), DataGridViewComboBoxColumn)

CBox.Value = CCol.Items(CCol.Items.Count - 1)

---

This sets the value of the combobox in column 0 of row NewRowIndex to the last value from the list defined in the column settings for column 0

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I tested the code and it did not work. I had to change it. My DataGridViewComboBoxColumn is bound to a database table. I filled its DataSourse, DataValue and DataDisplay properties. My DataValue data type is System.Int32 and my DataDisplay data type is String. So the value property of the DataGridViewComboBoxCell variable CBox will be System.int32. Therefore If I want to display the lastest items of the combo list I would have to write:

Code:

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Private Sub ComboCell_Fill(ByVal pFil As Integer, _
                                ByVal pCol As Integer, _
                                ByRef pG As DataGridView, _
                                ByVal pId As Long)

Dim CBox As DataGridViewComboBoxCell = CType(pG.Rows(pFil).Cells(pCol), DataGridViewComboBoxCell)
Dim CCol As DataGridViewComboBoxColumn = CType(pG.Columns(pCol), DataGridViewComboBoxColumn)

'This option if you want to display then combo by its DataValue property     
 CBox.Value = CType(pId, System.Int32)
'This option if you want to display the last item of the combobox collection.
 CBox.Value = CType(CCol.Items(CCol.Items.Count - 1), DataRowView).Row(0)       


pG.UpdateCellValue(pCol, pFil)

 End Sub

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I hope this to be usefull, because I had to spend much time searching and debugging to learn this.

Quote:

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Originally Posted by PedroZorro

Thanks a lot. If this code works I will kiss ....

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Quote:

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Quote:

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Originally Posted by PedroZorro

I tested the code and it did not work. I had to change it. My DataGridViewComboBoxColumn is bound to a database table. I filled its DataSourse, DataValue and DataDisplay properties. My DataValue data type is System.Int32 and my DataDisplay data type is String. So the value property of the DataGridViewComboBoxCell variable CBox will be System.int32. Therefore If I want to display the lastest items of the combo list I would have to write:

Code:

---

Private Sub ComboCell_Fill(ByVal pFil As Integer, _
                                ByVal pCol As Integer, _
                                ByRef pG As DataGridView, _
                                ByVal pId As Long)

Dim CBox As DataGridViewComboBoxCell = CType(pG.Rows(pFil).Cells(pCol), DataGridViewComboBoxCell)
Dim CCol As DataGridViewComboBoxColumn = CType(pG.Columns(pCol), DataGridViewComboBoxColumn)

'This option if you want to display then combo by its DataValue property     
 CBox.Value = CType(pId, System.Int32)
'This option if you want to display the last item of the combobox collection.
 CBox.Value = CType(CCol.Items(CCol.Items.Count - 1), DataRowView).Row(0)       


pG.UpdateCellValue(pCol, pFil)

 End Sub

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I hope this to be usefull, because I had to spend much time searching and debugging to learn this.

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Thanks! It works for me. I searched for 2 days and this is the only solution that really works!

Hi... is this code functional in C#? Hope someone can help me, I've been google-ing for over a week... I will try to addapt the code to C# and I'll let you know if it works.

I wrote the following code:

columnaProducto = new CType(dataGridViewDetalle.Columns[0], new DataGridViewComboBoxColumn());

The type or namespace name 'CType' could not be found (are you missing a using directive or an assembly reference?)

anyone know if I need to add a reference or something? Remenber I'm developing in C#

CType as well as several other functions beginning with C are members of the VB lanuage classes. I think you can add a reference to these and use them under C#.

Can you post your complete code?
I don't understand when you call sub "ComboCell_Fill"

P.S.: Sorry for my bad English...

Quote:

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Originally Posted by gino.o

Can you post your complete code?
I don't understand when you call sub "ComboCell_Fill"

P.S.: Sorry for my bad English...

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You do realise that this thread is 6 years old! Please do not revive old threads in the future.