How can I make a specific row cell readonly(not editable) on XtraGrid? For example just for row[0] but not all rows.
You can use the GridView.CustomRowCellEdit event:
//...
var repositoryItemTextEditReadOnly = new DevExpress.XtraEditors.Repository.RepositoryItemTextEdit();
repositoryItemTextEditReadOnly.Name = "repositoryItemTextEditReadOnly";
repositoryItemTextEditReadOnly.ReadOnly = true;
//...
void gridView1_CustomRowCellEdit(object sender, CustomRowCellEditEventArgs e) {
if(e.RowHandle == 0)
e.RepositoryItem = repositoryItemTextEditReadOnly;
}