主题：[求助]TextBox 如何在光标位置插入字符

按钮事件

Dim txt As WinForm.TextBox = e.Form.Controls("TextBox1")
msgbox(vars("sstart"))
Dim i As Integer = vars("sstart")
txt.text = txt.text.SubString(0,i) & "+" & txt.text.SubString(i)
txt.Select
txt.SelectionStart = i+1
txt.SelectionLength = 0

TextBox的Leave事件

vars("sstart") = e.sender.SelectionStart