以下是使用VB实现局域网文件传输的两种主要方法，供参考：

### 一、基于TCP协议的文件传输（推荐）

TCP协议提供可靠的、面向连接的传输服务，适合大文件传输。以下是实现步骤和示例代码：

#### 1. 服务器端代码（TCP协议）

```vb

Imports System.Net.Sockets

Imports System.Text

Module TCPFileServer

Sub Main()

Dim listener As New TcpListener(IPAddress.Any, 12345)

listener.Start()

Console.WriteLine("服务器已启动，等待客户端连接...")

While True

Dim client As TcpClient = listener.AcceptTcpClient()

Console.WriteLine("客户端已连接")

Dim stream As NetworkStream = client.GetStream()

Dim fileName As String = "接收文件.txt"

Dim fileBytes() As Byte() = File.ReadAllBytes(fileName)

' 发送文件名和长度

stream.Write(Encoding.ASCII.GetBytes(fileName & Environment.NewLine))

stream.Write(BitConverter.GetBytes(fileBytes.Length).ToArray())

' 读取文件并发送

stream.Write(fileBytes, 0, fileBytes.Length)

' 关闭连接

stream.Close()

client.Close()

End While

End Sub

End Module

```

#### 2. 客户端代码（TCP协议）

```vb

Imports System.Net.Sockets

Imports System.Text

Module TCPFileClient

Sub Main()

Dim host As String = "192.168.1.100" ' 服务器IP地址

Dim port As Integer = 12345

Dim fileName As String = "发送文件.txt"

Using client As New TcpClient(host, port)

Dim stream As NetworkStream = client.GetStream()

' 发送文件名和长度

stream.Write(Encoding.ASCII.GetBytes(fileName & Environment.NewLine))

stream.Write(BitConverter.GetBytes(File.ReadAllBytes(fileName).Length).ToArray())

' 接收文件

Dim buffer(1024 * 1024) As Byte() ' 1MB缓冲区

Dim bytesRead As Integer

Dim totalBytesReceived As Integer = 0

Do While bytesRead > 0

bytesRead = stream.Read(buffer, 0, buffer.Length - totalBytesReceived)

If bytesRead = 0 Then Exit Do

stream.Write(buffer, totalBytesReceived, bytesRead)

totalBytesReceived += bytesRead

Loop

' 保存文件

File.WriteAllBytes(fileName, buffer, totalBytesReceived)

' 关闭连接

stream.Close()

client.Close()

End Using

End Sub

End Module

```

### 二、基于UDP协议的文件传输（适合小文件）

UDP协议无连接且不可靠，但传输效率高。以下是实现思路：

1. 客户端将文件分块发送，每块8KB；

2. 服务器接收分块后重组文件；

3. 传输完成后进行简单校验。

#### 1. 服务器端代码（UDP协议）

```vb

Imports System.Net

Imports System.Net.Sockets

Imports System.Text

Module UDPFileServer

Private buffer(1024 * 1024) As Byte() = New Byte(1024 * 1024) ' 1MB缓冲区

Private port As Integer = 12345

Sub Main()

Dim listener As New UdpClient(port)

Console.WriteLine("服务器已启动，等待客户端连接...")

While True

Dim client As UdpClient = listener.AcceptUdpClient()

Console.WriteLine("客户端已连接")

Dim stream As IPEndPoint = client.RemoteEndPoint

Dim bytesReceived As Integer = client.Receive(buffer)

' 处理接收到的数据（简单回显）

client.Send(buffer, 0, bytesReceived, stream)

' 关闭连接

client.Close()

End While

End Sub

End Module

```

#### 2. 客户端代码（UDP协议）

```vb

Imports System.Net

Imports System.Net.Sockets

Imports System.Text

Module UDPFileClient

Private filePath As String = "发送文件.txt"

Private port As Integer = 12345

Sub Main()

Dim fileBytes() As Byte() = File.ReadAllBytes(filePath)

Dim fileName As String = Path.GetFileName(filePath)

Using client As New UdpClient(port)

' 发送文件名和长度

Dim fileNameBytes() As Byte() = Encoding.ASCII.GetBytes(fileName & Environment.NewLine)

Dim lengthBytes() As Byte() = BitConverter.GetBytes(fileBytes.Length)

client.Send(fileNameBytes, 0, fileNameBytes.Length)

client.Send(lengthBytes, 0, lengthBytes.Length)

' 发送文件内容

client.Send(fileBytes, 0, fileBytes.Length)

End