//¸ù¾Ý°à¼¶²éѯ private void cboClass_SelectedIndexChanged(object sender, EventArgs e) { if (this.cboClass.SelectedIndex == -1) { MessageBox.Show("请选择要查询的班级!", "查询提示"); return; } //显示查询结果 this.dgvScoreList.DataSource = objScoreService.QueryScoreList(this.cboClass.Text.Trim()); QueryScore(this.cboClass.SelectedValue.ToString()); }