vb.net发送文件

VB.NET发送文件可以使用Socket进行网络通信。首先，我们需要创建一个服务器端和一个客户端。

服务器端代码如下：

Imports System.IO
Imports System.Net
Imports System.Net.Sockets

Public Class Server
    Public Shared Sub Main()
        Dim serverIp As IPAddress = IPAddress.Parse("服务器IP地址")
        Dim serverPort As Integer = 8888

        ' 创建服务器Socket
        Dim serverSocket As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
        serverSocket.Bind(New IPEndPoint(serverIp, serverPort))
        serverSocket.Listen(10)

        Console.WriteLine("等待客户端连接...")
        Dim clientSocket As Socket = serverSocket.Accept()
        Console.WriteLine("客户端已连接")

        ' 读取文件
        Dim filePath As String = "文件路径"
        Dim fileBytes As Byte() = File.ReadAllBytes(filePath)

        ' 发送文件大小给客户端
        Dim fileSize As Integer = fileBytes.Length
        Dim fileSizeBytes As Byte() = BitConverter.GetBytes(fileSize)
        clientSocket.Send(fileSizeBytes)

        ' 发送文件给客户端
        clientSocket.Send(fileBytes)
        Console.WriteLine("文件已发送")

        ' 关闭连接
        clientSocket.Shutdown(SocketShutdown.Both)
        clientSocket.Close()
        serverSocket.Close()
        Console.WriteLine("连接已关闭")
    End Sub
End Class

客户端代码如下：

Imports System.IO
Imports System.Net
Imports System.Net.Sockets

Public Class Client
    Public Shared Sub Main()
        Dim serverIp As IPAddress = IPAddress.Parse("服务器IP地址")
        Dim serverPort As Integer = 8888

        ' 创建客户端Socket
        Dim clientSocket As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
        clientSocket.Connect(New IPEndPoint(serverIp, serverPort))

        ' 接收服务器发送的文件大小
        Dim fileSizeBytes(3) As Byte
        clientSocket.Receive(fileSizeBytes)
        Dim fileSize As Integer = BitConverter.ToInt32(fileSizeBytes, 0)

        ' 接收文件内容
        Dim receivedBytes As Integer = 0
        Dim buffer(1024) As Byte
        Using fileStream As New FileStream("保存文件路径", FileMode.Create, FileAccess.Write)
            While receivedBytes < fileSize
                Dim bytesRead As Integer = clientSocket.Receive(buffer)
                fileStream.Write(buffer, 0, bytesRead)
                receivedBytes += bytesRead
            End While
        End Using
        Console.WriteLine("文件已接收")

        ' 关闭连接
        clientSocket.Shutdown(SocketShutdown.Both)
        clientSocket.Close()
        Console.WriteLine("连接已关闭")
    End Sub
End Class

注意替换代码中的服务器IP地址、服务器端口、文件路径和保存文件路径为实际的值。服务器端首先等待客户端连接，然后读取要发送的文件并发送给客户端。客户端首先连接服务器，然后接收服务器发送的文件大小，最后按照文件大小逐步接收文件内容并保存到本地。

运行服务器端和客户端，即可完成文件的发送和接收过程。