private void txtSearch_TextChanged(object sender, EventArgs e) { if (txtSearch.Text == string.Empty) { LoadData(); } else { CategoryBL objTest = new CategoryBL() { CategoryName = txtSearch.Text.ToLower() }; var dt = objTest.SearchByName(); AutoCompleteStringCollection coll = new AutoCompleteStringCollection(); txtSearch.AutoCompleteMode = AutoCompleteMode.Suggest; txtSearch.AutoCompleteSource = AutoCompleteSource.CustomSource; txtSearch.AutoCompleteCustomSource = coll; if (dt.Count > 0) { dgvCategory.DataSource = dt; } } }