VB中让文本框显示文本文件内容

Question

VB题：窗体上有一个Drivelestbox控件Drive1,一个Dirlistbox控件Dir1,一个Filelistbox控件File1，一个Combo1控件，一个TEXT控件，要求在用户选择DRIVE1控件中的驱动器后，Dri1控件中的目录随之改变，当Dir1中的目录改变后File1控件中的文件随之改变，Combo1内容改动时File1文件类型过滤成TXT，当选定File1中文本文件时在Text1中显示文件内容，编写此程序

当选定File1中文本文件时在Text1中显示文件内容，这个不会，请老师指导，请看图片
这是我写的，哪些需要改变
Private Sub Combo1_Click()
File1.Pattern = "*.txt"

End Sub

Private Sub Dir1_Change()
ChDir Dir1.Path
File1.Path = Dir1.Path

End Sub

Private Sub Drive1_Change()
ChDrive Drive1.Drive
Dir1.Path = Drive1.Drive

End Sub

Private Sub File1_Click()
Text1.Text = File1.FileName

End Sub

Private Sub Form_Load()
Combo1.AddItem "*.txt"

End Sub

Answer 1

Private Sub Combo1_Click()
File1.Pattern = combo1.text

End Sub

Private Sub Dir1_Change()
File1.Path = Dir1.Path

End Sub

Private Sub Drive1_Change()
Dir1.Path = Drive1

End Sub

Private Sub File1_Click()
Open File1.Path & "\" & File1.FileName For Input As #1
Do While Not EOF(1)
Line Input #1, temp
str1 = str1 & temp & vbCrLf
Loop
Close #1
Text1.Text = str1

End Sub

Private Sub Form_Load()
Combo1.AddItem "*.txt"

End Sub

Answer 2

Private Sub File1_Click()
Open File1.Path & "\" & File1.FileName For Input As #1
Do While Not EOF(1)
Line Input #1, temp
str1 = str1 & temp & vbCrLf
Loop
Close #1
Text1.Text = str1
End Sub