如何使textbox上的數據跟隨combobox改變而改變

[derek]

數據綁定如下:
當選擇不同的合同備案號時textbox上的數據不會跟隨改變, 如何使textbox上的數據跟隨combobox改變而改變?

this.cmbhtbah.DataSource=this.ds.Tables["合同備案"];
this.cmbhtbah.DisplayMember ="合同備案號";
this.cmbhtbah.ValueMember="合同備案號";
this.cmbhtbah.DataBindings.Add("Text",this.ds,"合同備案.合同備案號");
this.cmbhtbah.DataBindings.Add("SelectedValue",this.ds,"合同備案.合同備案號");


this.lblhth.DataBindings.Add("Text",this.ds,"合同備案.合同號");
this.lblmyxz.DataBindings.Add("Text",this.ds,"合同備案.貿易性質");
this.lblmygb.DataBindings.Add("Text",this.ds,"合同備案.貿易國別");

[derek]

急啊!

[gweidian]

UP