this.cboVendor.SelectedIndexChanged -= new System.EventHandler(this.cboVendor_SelectedIndexChanged); cboVendor.DataSource = myClass.RunQueryCmd(strSqlCmd); cboVendor.DisplayMember = "SupplierCode"; //添加事件 this.cboVendor.SelectedIndexChanged += new System.EventHandler(this.cboVendor_SelectedIndexChanged);