c# add a dgv row with a dataGridViewComboBoxCell

Question

I'm currently trying to add a ComboBox to a dataGridView.

In the DGV, there are 5 columns: checkbox, string, string, combobox, combobox.

both combobox-columns are configured as datagridviewcomboboxcolumns (via VisualStudio designer). My problem is to add rows.

My current try is: the columns are already defined and I add rows via dataGridView.Rows.Add. For that, I'm using an array of objects. Example:

dataGridViewRow row = new dataGridViewRow();
object[] obj = new object[5] {true, "str1", "str2", null, null};
dataGridView1.Rows.Add(obj);

This passes without any errors. But logically, the comboBoxes aren't filled with anything.

I tried setting a datasource to the 4th and 5th cell of a row:

Error...Using ROW.dataGridViewComboBoxCell.Items.Add: Items are not displayed...

filling obj[3] and 4 with a new DGVcomboBoxCell or -Column:

 Error... :The error message says "The dataGridViewComboBoxCell-Value is invalid.

Further information: Each column should have the same Items in the comboBoxes. (These are previously loaded via internet, as xml). Setting a dataSource to the two columns destroys the whole DGV (I think because the other colmns don't have a Datasource). In a nutshell: How to add Rows to a DGV which contain comboboxes filled with items?

Sincerely, NoMad

edit: here's some code to solve my problem:

        DataGridViewCheckBoxColumn check = new DataGridViewCheckBoxColumn();
        check.Name = "Col1";
        dataGridView1.Columns.Add(check);

        dataGridView1.ColumnCount = 3;
        dataGridView1.Columns[1].Name = "Col2";
        dataGridView1.Columns[2].Name = "Col3";

        object[] row = new object[] { true, "str1", "str2" };
        dataGridView1.Rows.Add(row);

        DataGridViewComboBoxColumn combo1 = new DataGridViewComboBoxColumn();
        DataGridViewComboBoxColumn combo2 = new DataGridViewComboBoxColumn();

        combo1.Name = "Col4";
        combo1.Items.Add("100x100");
        combo1.Items.Add("200x200");

        combo2.Name = "Col5";
        combo2.Items.Add("option1");
        combo2.Items.Add("option2");

        dataGridView1.Columns.Add(combo1);
        dataGridView1.Columns.Add(combo2); 

First add a row, cast columns, configure them and add them to the row. No Columns need to be previously specified in the designer.

Answer 1

If you need to keep configured columns try something like this:

dataGridView1.Rows.Add();
DataGridViewRow tmp = dataGridView1.Rows[dgvMatw.Rows.Count - 1];
tmp.Cells[0] = true;
tmp.Cells[1] = "str1";
tmp.Cells[2] = "str2";
((DataGridViewComboBoxCell)tmp.Cells[3]).Value = 1;
((DataGridViewComboBoxCell)tmp.Cells[4]).Value = 2;

Values 1 and 2 where example only. It must be type of your DataGridViewComboBoxColumn.ValueMember. I was searching for this topic, so I thought someone could use it.

Answer 2

I'm not entirely clear what you're trying to do here, but if you're just trying to choose a value from the combobox for each row you add, you can choose an existing combobox value as a string.

If I have a two column datagridview, both with comboboxes that are pre-populated (I populated my comboboxes in the datagridview control itself by simply editing each column and adding my choices to the collection there), then I can do this:

Public Class Form1
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim newRow(1) As Object
        newRow(0) = "Foo"
        newRow(1) = "Bar"
        DataGridView1.Rows.Add(newRow)
    End Sub
End Class

So "Foo" and "Bar" are already choices in the comboboxes. I can populate each row by simply referring to the choice I want by name. I would guess I could also do this by index number if I wanted to.

Hope this helps!

Answer 3

You can use this solution for adding items to datagird view combobox column

 DataSet ds; //class variable
    public Form1()
    {
        InitializeComponent();

        ds = new DataSet();
        //column 1 (normal textColumn):
        dataGridView1.Columns.Add("col1", "Column1");
        //column 2 (comboBox):
        DataGridViewComboBoxColumn comboCol = new DataGridViewComboBoxColumn();
        comboCol.Name = "cmbColumn";
        comboCol.HeaderText = "combobox column";
        dataGridView1.Columns.Add(comboCol);

        //using dataTable for each datasource:             
        for (int i = 0; i < 10; i++)
        {
            string text = "item " + i; //data for text
            int[] data = { 1 * i, 2 * i, 3 * i }; //data for comboBox:

            //create new dataTable:
            DataTable table = new DataTable("table" + i);
            table.Columns.Add("column1", typeof(string));

            //fillig rows:
            foreach (int item in data)
                table.Rows.Add(item);

            //add table to dataSet:
            ds.Tables.Add(table);

            //creating new row in dgv (text and comboBox):
            CreateCustomComboBoxDataSouce(i, text, table);
        }
    }

    private void CreateCustomComboBoxDataSouce(int row, string texst, DataTable table) //row index ,and two parameters
    {
        dataGridView1.Rows.Add(texst);
        DataGridViewComboBoxCell comboCell = dataGridView1[1, row] as DataGridViewComboBoxCell;
        comboCell.DataSource = new BindingSource(table, null);
        comboCell.DisplayMember = "column1"; //name of column indataTable to display!!
        comboCell.ValueMember = "column1"; // vlaue if needed 
        //(mostly you used these two propertes like: Name as DisplayMember, and Id as ValueMember)
    }

if the above is not working take a look at the solution below..

you can do it via DataGridViewComboBoxCell. According to the cell's rowIndex, set different datasource(string[]) to the different DataGridViewComboBoxCell. Coding like this:

    private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
    {
        if (e.ColumnIndex == 0)
        {
            DataGridViewComboBoxCell combo = this.dataGridView1[0, e.RowIndex] as DataGridViewComboBoxCell;

                if (e.RowIndex == 0)
                {
                    //these data will be displayed in comboBox:
                     string[] data= {"item A1", "item B1", "item C1"};  
                    combo.DataSource = data;
                }
                if (e.RowIndex == 1)
                {
                    //these data will be displayed in comboBox:
                    string[] data = {"item A2", "item B2", "item C2"};                        
                    combo.DataSource = data;
                }
                if (e.RowIndex == 2)
                {
                    //these data will be displayed in comboBox:
                    string[] data = { "item A3", "item B3", "item C3" };                           
                    combo.DataSource = data;
                }

            }
        }
    }