Form1”是“TcpApplication1”中的类型，不能用作表达式

以下是我的程序，运行的时候出现错误：“Form1”是“TcpApplication1”中的类型，不能用作表达式。
是怎么回事啊，请高手指点啊，我的程序里面好像没有用到Form1的表达式啊（Form1是窗体名称，TcpApplication1是项目名称）Imports System.Windows.Forms
Imports System.Threading
Imports System.Net.Sockets
Imports System.Net
Imports System.IOPublic Class Form1    Delegate Sub SetTextCallback(ByVal s As String)
    Delegate Sub SetReadCallback()
    Delegate Sub SetReadOutputCallback()    Private connection As Socket
    Private readThread As Thread    Private socketStream As NetworkStream    Private writer As BinaryWriter
    Private reader As BinaryReader    Private Sub New()
        MyBase.new()        ' 此调用是 Windows 窗体设计器所必需的。
        InitializeComponent()        ' 在 InitializeComponent() 调用之后添加任何初始化。        readThread = New Thread(AddressOf RunServer)
        readThread.Start()    End Sub    Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing        System.Environment.Exit(System.Environment.ExitCode)
    End Sub    Private Sub TxtInput_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TxtInput.KeyDown        Try            If (e.KeyCode = Keys.Enter AndAlso Not connection Is Nothing) Then                writer.Write("SERVER>>> " & TxtInput.Text)                TxtOutput.Text &= vbCrLf & " Server>>> " & TxtInput.Text                If TxtInput.Text = "TERMINATE" Then                    connection.Close()
                End If                TxtInput.Clear()
            End If        Catch exception As SocketException            TxtOutput.Text &= vbCrLf & "Error writing object"        End Try
    End Sub    Public Sub RunServer()        Dim listener As TcpListener
        Dim counter As Integer = 1        Try            listener = New TcpListener(IPAddress.Parse("192.168.99.112"), 5000)
            listener.Start()            While True                settext("Waiting for connection" & vbCrLf)                connection = listener.AcceptSocket                socketStream = New NetworkStream(connection)                writer = New BinaryWriter(socketStream)
                reader = New BinaryReader(socketStream)                settext("Connection " & counter & " received." & vbCrLf)                writer.Write("SERVER>>> Connection successful")                setRead()                Dim theReply As String = ""                Try                    Do
                        theReply = reader.ReadString                        settext(vbCrLf & theReply)                    Loop While (theReply <> "Client>>> TREMINATE" AndAlso connection.Connected)                Catch inputOutputException As IOException
                    MessageBox.Show("Client application closing")                Finally                    settext(vbCrLf & "User terminated connection")
                    setReadOutput()
                    
                    writer.Close()
                    reader.Close()
                    socketStream.Close()
                    connection.Close()
                    counter += 1                End Try            End While        Catch inputOutputException As IOException
            MessageBox.Show("Server application closing")        End Try
    End Sub    Private Sub settext(ByVal s As String)        If TxtOutput.InvokeRequired Then            Dim d As New SetTextCallback(AddressOf settext)
            Me.Invoke(d, New Object() {s})
        Else
            Me.TxtOutput.Text &= s
        End If    End Sub    Private Sub setRead()        If TxtInput.InvokeRequired Then            Dim d As New SetReadCallback(AddressOf setRead)
            Me.Invoke(d, New Object() {})
        Else
            Me.TxtInput.ReadOnly = False
        End If    End Sub    Private Sub setReadOutput()        If TxtOutput.InvokeRequired Then            Dim d As New SetReadOutputCallback(AddressOf setReadOutput)
            Me.Invoke(d, New Object() {})
        Else
            Me.TxtOutput.ReadOnly = False        End If    End SubEnd Class