有代码时正常，无代码或代码错误时，未将对象引用设置到对象的实例。
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
If nd Is Nothing Then
MessageBox.Show("产品代码不存在!","提示")
Return
End If
'Else
s1 = s.substring(0,5)
nd = nd.nodes(s1)
If nd Is Nothing Then
MessageBox.Show("产品代码不存在!","提示")
Return
End If
'Else
s1 = s.substring(0,7)
nd = nd.nodes(s1)
If nd Is Nothing Then
MessageBox.Show("产品代码不存在!","提示")
Return
End If
'Else
's1 = s.substring(0,11)
s1 = s
nd = nd.nodes(s1)
trv.SelectedNode = nd '返回选定的节点
nd.EnsureVisible '节点可见
trv.Select()
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Post By：2021/1/25 11:48:00 [显示全部帖子]
