private void btnSearch_Click(object sender, EventArgs e) { DatabaseColumn databaseColumn = new DatabaseColumn(); List <DatabaseColumn> list = new List <DatabaseColumn>(); CombineDataGridView combineDataGridView = new CombineDataGridView(); if (txtSearch.Text != "") { Connector connector = new MYSQLDatabaseConnection(); connector.establish(); if (redioBtnCategoryName.Checked == true) { databaseColumn.category_name = txtSearch.Text.ToString(); connector.SetData(databaseColumn); list = connector.SearchCategoryWithName(); combineDataGridView.SetDataGridViewList(list, mDgv);//connect main window datagridview } else if (redioBtnCategoryId.Checked == true) { databaseColumn.category_id = txtSearch.Text.ToString(); connector.SetData(databaseColumn); list = connector.SearchCategoryWithId(); combineDataGridView.SetDataGridViewList(list, mDgv); } if (list.Count > 0) { txtCategoryId.Text = list[0].category_id; txtCategoryName.Text = list[0].category_name; } else { txtCategoryName.Clear(); txtCategoryId.Clear(); } } else { txtCategoryName.Clear(); txtCategoryId.Clear(); } }