ComboBox cmb = (ComboBox) m_syncGrid.Table.Records[i].GetValue("DBETVT");you should be populating the datasource for the combobox, Constants.DataBase.dt_ETVT. And to set a particular value into the cell, you should be setting the value in the Constants.DataBase.col_ETVT field of the m_syncGrid.Table.Records[i] record. Normally, you do not have to worry about trying to set display values to be seen in the comboboxes dropdown. They should be automatically set by the grid for the information you provided in the columns Appearance property.
m_syncGrid.TableDescriptor.Columns[Constants.DataBase.col_ETVT].Appearance.AnyRecordFieldCell.DataSource = Constants.DataBase.dt_ETVT; m_syncGrid.TableDescriptor.Columns[Constants.DataBase.col_ETVT].Appearance.AnyRecordFieldCell.DisplayMember = "Value"; m_syncGrid.TableDescriptor.Columns[Constants.DataBase.col_ETVT].Appearance.AnyRecordFieldCell.ValueMember = "Key";the value member of the combobox is something call "Key" which is a column in Constants.DataBase.dt_ETVT (assumed to be a DataTable). The value you set into the grid should be something like a "Key" object. So, if "Key" is an Int, then you should put an Int into the record. If "Key" is a string, you should put a string into the record. More over, the value you set must be an entry in the Constants.DataBase.dt_ETVT DataTable (otherwise the key would not be found in the look-up table). Another comment is that the System.Type of the column in the grid must be the same as the System.Type of the "Key". So, if the "Key" column in Constants.DataBase.dt_ETVT holds an int, then column in the grid''s DataSource that maps to m_syncGrid.TableDescriptor.Columns[Constants.DataBase.col_ETVT] should also hold an int. If you upload a sample you want to see working, I can try to tweak it for you.
m_syncGrid.TableDescriptor.Columns[Constants.DataBase.col_ETVT].Appearance.AnyRecordFieldCell.CellType = "ComboBox";and run your project. Without the combobox celltype being set, you should just see whatever you are trying to set in that column in the grid. If this works, then the problem is likely on the combobox side of things. The first thing to do is to check the datasource of teh combobox to make sure it is what you expect. For example, you can drop a DataGrid on this form, and set its DataSource to be the combobox DataSource. Does it show what you expect?