C#socket服务端与客户端互相选择和发送图片，收到的图片可以显示在picturebox控件中

下面是一个简单的 C# Socket 图片传输示例，服务端和客户端可以互相选择和发送图片，收到的图片可以显示在 PictureBox 控件中。

服务端：

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Windows.Forms;

namespace SocketServer
{
    public partial class FormServer : Form
    {
        private TcpListener listener;
        private TcpClient client;
        private NetworkStream stream;
        private byte[] buffer;

        public FormServer()
        {
            InitializeComponent();
        }

        private void buttonStart_Click(object sender, EventArgs e)
        {
            listener = new TcpListener(IPAddress.Any, 8000);
            listener.Start();
            listBoxLog.Items.Add("Waiting for client...");

            buttonStart.Enabled = false;
            buttonStop.Enabled = true;

            AcceptClient();
        }

        private async void AcceptClient()
        {
            client = await listener.AcceptTcpClientAsync();
            listBoxLog.Items.Add("Client connected.");

            stream = client.GetStream();
            buffer = new byte[client.ReceiveBufferSize];

            ReceiveImage();
        }

        private async void ReceiveImage()
        {
            int bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
            if (bytesRead > 0)
            {
                MemoryStream ms = new MemoryStream(buffer, 0, bytesRead);
                pictureBoxServer.Image = System.Drawing.Image.FromStream(ms);
                listBoxLog.Items.Add(string.Format("Image received. Size: {0} bytes.", bytesRead));
            }

            ReceiveImage();
        }

        private void buttonStop_Click(object sender, EventArgs e)
        {
            if (stream != null)
                stream.Close();
            if (client != null)
                client.Close();
            if (listener != null)
                listener.Stop();

            listBoxLog.Items.Add("Server stopped.");

            buttonStart.Enabled = true;
            buttonStop.Enabled = false;
        }
    }
}

客户端：

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Windows.Forms;

namespace SocketClient
{
    public partial class FormClient : Form
    {
        private TcpClient client;
        private NetworkStream stream;
        private byte[] buffer;

        public FormClient()
        {
            InitializeComponent();
        }

        private void buttonConnect_Click(object sender, EventArgs e)
        {
            client = new TcpClient();
            client.Connect(textBoxIP.Text, 8000);
            stream = client.GetStream();
            buffer = new byte[client.ReceiveBufferSize];

            buttonConnect.Enabled = false;
            buttonDisconnect.Enabled = true;
        }

        private async void buttonSend_Click(object sender, EventArgs e)
        {
            if (pictureBoxClient.Image == null)
            {
                MessageBox.Show("Please choose an image to send.");
                return;
            }

            MemoryStream ms = new MemoryStream();
            pictureBoxClient.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
            byte[] imageBytes = ms.ToArray();

            await stream.WriteAsync(imageBytes, 0, imageBytes.Length);
            listBoxLog.Items.Add(string.Format("Image sent. Size: {0} bytes.", imageBytes.Length));
        }

        private void buttonDisconnect_Click(object sender, EventArgs e)
        {
            if (stream != null)
                stream.Close();
            if (client != null)
                client.Close();

            listBoxLog.Items.Add("Client disconnected.");

            buttonConnect.Enabled = true;
            buttonDisconnect.Enabled = false;
        }

        private void buttonChoose_Click(object sender, EventArgs e)
        {
            OpenFileDialog dialog = new OpenFileDialog();
            dialog.Filter = "Image Files (*.jpg, *.jpeg, *.png, *.bmp)|*.jpg;*.jpeg;*.png;*.bmp";
            if (dialog.ShowDialog() == DialogResult.OK)
            {
                pictureBoxClient.Image = System.Drawing.Image.FromFile(dialog.FileName);
            }
        }
    }
}

注意事项：

1. 在实际应用中，需要考虑网络延迟和传输的数据量大小等因素，可能需要对数据进行分割和压缩等处理。
2. 在传输二进制数据时，需要注意编码方式，通常使用 UTF8 或 Unicode 编码。
3. 在客户端选择图片时，需要过滤掉非图片文件。