Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.Event Args) Handles Button4.Click
Dim sr As IO.StreamReader
Dim filename, prompt, title, street As String
Dim housenumber As Double prompt = "enter the name of the file containing the information."
title = "name of file"
filename = InputBox(prompt, title)
sr = IO.File.OpenText(filename) '假设在对话框内输入字母 v ，则弹出错误：未能找到 文件“F:\VB.net-project\5\5\bin\Debug\v”，请问问题出在哪啊
housenumber = CDbl(sr.ReadLine)
street = sr.ReadLine
sr.Close()
TextBox1.Text = housenumber
End Sub

v 是上一句代码中的 inputbox 所输入的字符，而不是文件。代码中的filename就是要从
inputbox中获取字符信息的

一定得是存在的文件 用try