DatagridViewComboboxCell value changed in C#

Question

I have a DatagridviewCombobox Column and am creating DatagridviewCombobox Cells on each row and adding items to it. When I change the value of any (combobox) cell, it throws an exception saying that Datagridviewcombobox cell value is not valid. and the cell value becomes '1'.

I am working on the datagridview_currentcelldirtystatechange event, but haven't been able to make it work.

The code below is creating rows and filling combobox cells with a sequence numbers.

    int _rowLimit =1;

    for (int i = _rowLimit - 1; i < _rowLimit; i++)
    {          
         datagridview.Rows.Add();
         item = i + 1;
         datagridview[myColumn, i].Value = _rowLimit;                   

         DataGridViewComboBoxCell oCell = datagridview.CurrentRow.Cells[myColumn] as DataGridViewComboBoxCell;
         oCell.Items.Add(item);

         ((DataGridViewComboBoxColumn)datagridview.Columns[myColumn]).Items.IndexOf(_rowLimit);
         ((DataGridViewComboBoxColumn)datagridview.Columns[myColumn]).Items.Insert(index, item);
    }

And below is what i am doing in datagridview_currentcelldirtystatechange event:

for (int innerIndex = 0; innerIndex < datagridview.Rows.Count; innerIndex++)
    {
      long sequence = 3;
      long oldSequence = 2;
      long tempValue= Convert.ToInt64(datagridview.Rows[innerIndex].Cells[myColumn].Value);
      if (tempValue <= sequence && tempValue> oldSequence)
      {                    
           datagridview.Rows[innerIndex].Cells[myColumn].Value = tempValue+ 1; // increment   the sequence 
// value here i am getting is correct , but it doesn't show in the DatagridviewCombobox cell where it gets changed of gridview and the mentioned exception is thrown.

      }

Any help would be appreciated. Thanks.

Answer 1

the error on selectedindexChange value of the combobox cells and the exception of DataGridviewComboboxcell value is not valid .. that automatically did change the selected vlue to '1'.. i fixed this issue by adding the DatagridviewComboBoxColumn property in the designer file.

this.columnName.ValueType = typeof(long); 

typeof(long) // this is what what i wanted to show the value in the datagridviewcombobox column.

Issue has now resolved. Thanks.