CODEWITHSUNDEEP
c#datagridview
Chuck Wilbur
Chuck Wilbur

Reputation: 2620

Error: "DataGridViewComboBoxCell value is not valid." DataSource is list of basic type

I couldn't find a question on SO that exactly matched my problem.

Similar to this question and this question, I'm setting the DataSource on a DataGridViewComboBoxColumn to a list of things. In my case the things are simple types like doubles and ints, so the answers talking about ValueMembers and DisplayMembers don't do me a lot of good. When the user selects a value I get the dreaded "DataGridViewComboBoxCell value is not valid" error.

I could swallow the error with an empty dataGridView_DataError handler, but that is obviously a bad way to go.

Upvotes: 7

Views: 22843

Answers (4)

Nick Juelich
Nick Juelich

Reputation: 436

I struggled with the same type of issue and figured I would answer what I did to correct this issue.

List<int> myList = new List<int>();
//Populate list with data

DataGridViewComboBoxColumn c1 = new DataGridViewComboBoxColumn();
c1.ValueType = typeof(int);

c1.DataSource = myList;

dataGridView.Columns.Add(c1);

I hope I can help someone who still has this issue.

Upvotes: 0

SerenityNow
SerenityNow

Reputation: 1065

The problem for me was that the value my datasource was returning was not available in the combobox.... my combo had value 1, 2 and 3... but datasource wanted 4.

Upvotes: 0

Craig
Craig

Reputation: 1

This is finicky about sub-types. I still got the error when the ValueType was Int, but the DataSource contained a SQLServer SMALLINT (which a Visual Studio 2010 Quick-Watch on the DataSource said was an Int32 !). Changing the DB column from SMALLINT -> INT fixed it for me.

Upvotes: 0

Chuck Wilbur
Chuck Wilbur

Reputation: 2620

I found the answer here. It's also mentioned in this answer to the second link in my question. When setting the DataSource to a list of anything that's not a string, set the ValueType of the column to typeof(<your data type>)

        IList<double> kvChoices;
        // Populate kvChoices...
        DataGridViewComboBoxColumn kvCol =
            dataGridView1.Columns[0] as DataGridViewComboBoxColumn;
        kvCol.DataSource = kvChoices;
        kvCol.ValueType = typeof(double);

Upvotes: 21

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