I situation is same as Linn, were I have get data from datatable. SupplierID base on CategoryID. on debug mode the supplierID have list but the combobox is empty.

Can you email me the code you send to Linn? that fix the empty combobox isure

Thanks
Jack

What do I do when my underlying data object has a property of type int, but I want to treat it as an enum? I have a value in my database stored as an int that is effectively an enum and want to use a combobox like you show here. I keep getting cell value is not valid exceptions from the datagridview and I don’t know what to try next.

In DataGridViewComboBoxColumn, user has to go four clicks in order to pick an option:
1)select the cell
2)select the dropdown control within the cell
3)click to drop down control to display its items
4)select an item

Is there a way such that DataGridViewComboBoxColumn behaves like a normal combobox where user will only click dropdown box and then pick an option.

Thanks,

Reno

i set the data source and display member and value member but my problem is to set a default value to that combo box !!! thnaks in advance !!!

When working with the DataGridViewComboBoxColumn object that was bound to a datatable, I was getting the error: Cannot set Column “columnName” to be null. Please use DBNull instead. I got this error when attempting to select a blank item from the combobox. The blank item was an actual record in the source table for the combobox because the client wanted to be able to set a blank value for the column. So, in this case the value of the ValueMember was 574 and the value of the DisplayMember was “” (String.Empty).

After an hour and a half of DataGridView related articles, I finally came upon a DataGridView white paper article. One of the sections refers to handling null values in the grid. After quickly looking over the table that listed the default values of the DefaultCellStyle.NullValue property of each different column object, I noticed the default for the combobox column just happens to be String.Empty. So, after setting the DefaultCellStyle.NullValue property to System.DBNull.Value my error dissapeared. It appears that the grid was “confused” by my use of String.Empty as the DisplayMember of an item in the combobox when its default “null” value was also String.Empty. I hope someone else out there finds this information useful.

Take Care,
Ryan Hansen
When working with the DataGridViewComboBoxColumn object that was bound to a datatable, I was getting the error: Cannot set Column “columnName” to be null. Please use DBNull instead. I got this error when attempting to select a blank item from the combobox. The blank column was an actual record in the source table for the

I have a similar requirement in my project. I have placed a combo box in the data grid. I have also set the data source, datapropertyname, displaymember, valuemember for the combo. I have set bindingsource for the datagrid too. My problem is when I try to select a value from the combo, it doesn’t drop down. It doesn’t show the list. Can you please help me with this. Thanks.

I struggling with a DataGridView ComboboxColumn. More specifically with the CTRL+0 keystroke to set a dbnull value into the combobox.
The datagrid has a datasource with a dataset. The combobox shows an optional relationship with a “lookup table”.

It works fine…. That is to say it works fine if the type of valuemember of the combobox is for example a string. BUT if it is an integer ist doesn’t work. And of course the primarykey of the lookup tables is a identity integer.

It gives following error when I type in CTRL+0 : Cannot set Column “myColumn” to be Null. Please use DBNull instead.

Once again it works OK with a combobox if the value is of a string type.

Could you help me out?

Thanks is advance.

Best Regards,

Alexander