CODEWITHSUNDEEP
c#winforms
NateShoffner
NateShoffner

Reputation: 16829

DataGridViewComboBox DataSource

I currently have a 2-column wide DataGridView, the first column being a DataGridViewTextBoxColumn and the second a DataGridViewComboBoxColumn. I also have a pre-generated generic List (string) that is to be used as the DataSource for the DataGridViewComboBox for each row.

Finally, I have a loop that iterates through a series of strings and parses them accordingly, with extracted values being applied to respective cells using an as shown below:

dataGridView.Rows.Add("Column1Text", "Column2Text");

The gridview data is filled as expected, along with the DataGridViewComboBox properly displaying the ideal item.

The problem is, the DataGridViewComboBox, when clicked, does not drop down any items. I have checked that the DataGridViewComboBox contains items. The DataGridViewTextBoxColumn's AutoSizeMode is set to "Fill" if it's of any relevance.

Any insight as to what I may be doing wrong? Do I have to manually drop down the items when a given cell is clicked? Thanks.

Update

I have tried two different methods in terms of binding the generic list as the DataSource.

The first was binding the DataSource of the entire column itself via:

col_key.DataSource = KeyList;

The second method was binding the DataSource of each new DataGridViewComboBoxCell in the corresponding row:

(DataGridViewComboBoxCell)(row.Cells[1]).DataSource = KeyList;

Both of these methods compile and properly add the necessary items at runtime, but no items drop down when clicked.

Upvotes: 3

Views: 4511

Answers (3)

Peter Bill
Peter Bill

Reputation: 528

I had a similar problem. I found setting the EditMode property of the DGV to EditOnEnter (it was previously EditProgrammatically) fixed the problem. This can be done in the designer.

Upvotes: 0

Marvin Winks
Marvin Winks

Reputation: 13

I chose to handle this in the CellEnter event:

private void dataGridView1_CellEnter(object sender, DataGridViewCellEventArgs e)
    {
        if (e.ColumnIndex == 2)
        {
            DataGridViewComboBoxCell cell = this.dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex] as DataGridViewComboBoxCell;
            if (cell.DataSource == null)
            {
                cell.DataSource = this._ComboItemsBindingSource;
                cell.DisplayMember = "Value"; //lite-weight wrapper on string
                cell.ValueMember = "Value";   //where Value is a property
            }
        }
    }

Upvotes: 1

Amen Ayach
Amen Ayach

Reputation: 4348

To fill a grid combocolumn, you should treat it as regular Combo, datasource for combo should have a valuemember and a displaymember, so check the following example :

//Coded by Amen Ayach's DataClassBuilder @26/02/2012
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class iddesc{

    private int _id;
    public int id{
        get {
            return _id;
        }
        set {
            _id = value;
        }
    }

    private string _description;
    public string description{
        get {
            return _description;
        }
        set {
            _description = value;
        }
    }

}

To fill the grid :

    private void FillData()
    {
        List<iddesc> DataList = new List<iddesc>();
        for (int i = 1; i < 11; i++)
        {
            DataList.Add(new iddesc() { id = i, description = "Desc" + i.ToString() });
        }
        ComboCol.ValueMember = "id";
        ComboCol.DisplayMember = "description";
        ComboCol.DataSource = DataList;

        for (int i = 0; i < 10; i++)
        {
            grd.Rows.Add();
            grd[ComboCol.Name, i].Value = DataList[i].id;//Here you deliver the valuemember
            grd[Column1.Name, i].Value = DataList[i].description;
        }
    }

Upvotes: 0

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