还有个问题请教老师:按产品代码定位(代码如下),如果产品代码不存在则会出错,不知道判断加在什么地方Dim trv As WinForm.TreeView = e.Form.Controls("产品目录")
Dim s As String = e.Form.Controls("型号规格").text
Dim s1 As String = s.substring(0,3) '返回从指定位置开始指定长度的子字符串
Dim nd As WinForm.TreeNode = trv.nodes(s1) '获取的节点
s1 = s.substring(0,5)
nd = nd.nodes(s1)
s1 = s.substring(0,7)
nd = nd.nodes(s1)
's1 = s.substring(0,11)
s1 = s
nd = nd.nodes(s1)
If nd IsNot Nothing Then '如果节点存在
trv.SelectedNode = nd '返回选定的节点
Else
MessageBox.Show("没有该产品!","提示")
End If
nd.EnsureVisible '节点可见