我正在创建一个远程桌面程序，因此我开发了一个类，它可以获取客户端计算机的快照，并以字节数组格式将每个图像发送到服务器。然后服务器读取这些字节并将流转换为System.Drawing.Image类型。但Image.FromStream需要太长时间。每当我突破这一行时，它就会卡住。没有异常被抛出，并且在该行代码之后没有任何反应。
线路问题：
StreamingData（client，new DataEventArgs（Image.FromStream（stream，false，false）））;
完整代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Windows.Forms;
using System.Drawing;
namespace Simply_Remote_Desktop_Library
{
public sealed class RemoteDesktopListener
{
private TcpListener listner;
private TcpClient client;
public delegate void ConnectedEventHandler(TcpClient sender, EventArgs e);
public event ConnectedEventHandler Connected;
public delegate void IncommingDataEventHandler(TcpClient sender, DataEventArgs e);
public event IncommingDataEventHandler StreamingData;
public delegate void ConnectionEndedEventHandler(RemoteDesktopListener sender, EventArgs e);
public event ConnectionEndedEventHandler ConnectionEnded;
/// <summary>
/// Constructor (+1 Overloads)
/// </summary>
/// <param name="port">The port to listen for incoming connections.</param>
/// <param name="host_ip">The IP address of the client computer.</param>
public RemoteDesktopListener(int port, string host_ip)
{
IPAddress addr;
if (IPAddress.TryParse(host_ip, out addr))
{
if (port > 0 || port < 65535)
{
listner = new TcpListener(addr, port);
}
else if (port < 0 || port > 65535)
{
throw new RemoteDesktopException(new ArgumentOutOfRangeException("port"));
}
}
else
{
throw new RemoteDesktopException("Error: Invalid IP address in string format. Make sure it is in the right format.");
}
}
/// <summary>
/// Constructor (+1 Overloads)
/// </summary>
/// <param name="port">Port for server to listen for incoming connections.</param>
/// <param name="host_ip">Ip address of client.</param>
public RemoteDesktopListener(int port, IPAddress host_ip)
{
if (port > 0 && port < 65535)
{
listner = new TcpListener(host_ip, port);
}
else if (port < 0 && port > 65535)
{
throw new RemoteDesktopException("Error: Port number invalid! Range is from 0 - 65535.");
}
}
/// <summary>
/// Starts the listening process and establishes a connection to a client.
/// </summary>
public void BeginListening()
{
if (listner == null)
{
throw new RemoteDesktopException(new NullReferenceException());
}
else if (listner != null)
{
byte[] bytes = new byte[204800];
bool connected = false;
listner.Start();
//int i;
while (true)
{
client = listner.AcceptTcpClient();
if (connected == false)
{
Connected(client, new EventArgs());
connected = true;
}
NetworkStream stream = client.GetStream();
while (stream.DataAvailable == true)
{
StreamingData(client, new DataEventArgs(Image.FromStream(stream, false, false)));
}
client.Close();
ConnectionEnded(this, new EventArgs());
}
}
return;
}
/// <summary>
/// Starts listening for incoming connection requests.
/// </summary>
/// <param name="backlog">Maximum number of pending connection</param>
public void BeginListening(int backlog)
{
if (listner == null)
{
throw new RemoteDesktopException(new NullReferenceException());
}
else if (listner != null)
{
//byte[] bytes = new byte[204800];
bool connected = false;
listner.Start(backlog);
//int i;
while (true)
{
client = listner.AcceptTcpClient();
if (connected == false)
{
Connected(client, new EventArgs());
connected = true;
}
NetworkStream stream = client.GetStream();
while (stream.DataAvailable == true)
{
StreamingData(client, new DataEventArgs(Image.FromStream(stream, false, false)));
}
client.Close();
ConnectionEnded(this, new EventArgs());
}
}
return;
}
public void StopListening()
{
client.Close();
listner.Stop();
}
/// <summary>
/// Returns the System.Net.Sockets.Socket of the current session.
/// </summary>
public Socket Socket
{
get
{
return listner.Server;
}
}
~RemoteDesktopListener()
{
client.Close();
listner.Stop();
ConnectionEnded(this, new EventArgs());
}
}
public sealed class RemoteDesktopClient
{
private TcpClient client;
private Timer timer;
private Bitmap bitmap;
private System.Drawing.Imaging.PixelFormat format;
private Graphics g;
private NetworkStream stream;
public delegate void ConnectionCloseEventHandler(RemoteDesktopClient sender, EventArgs e);
public event ConnectionCloseEventHandler ConnectionClosed;
/// <summary>
/// Constructor (1 Overload)
/// </summary>
/// <param name="pixel_format">The bitmap's pixel format that will be used for every frame that is sent across the network.</param>
public RemoteDesktopClient(System.Drawing.Imaging.PixelFormat pixel_format)
{
format = pixel_format;
}
public void BeginConnection(int port, string host_ip)
{
IPAddress addr;
if (IPAddress.TryParse(host_ip, out addr))
{
if (port > 0 && port < 65535)
{
client = new TcpClient(host_ip, port);
timer = new Timer();
timer.Interval = Convert.ToInt32(Math.Pow(24, -1) * 1000); // 24 frames per second.
timer.Tick += new EventHandler(timer_Tick);
stream = client.GetStream();
timer.Enabled = true;
}
else if (port > 0 && port > 65535)
{
throw new RemoteDesktopException(new ArgumentOutOfRangeException("port"));
}
}
else
{
throw new RemoteDesktopException("Error: Invalid IP address in string format. Make sure it is in the right format.");
}
}
void timer_Tick(object sender, EventArgs e)
{
bitmap = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);
g = Graphics.FromImage(bitmap);
g.CopyFromScreen(0, 0, 0, 0, bitmap.Size);
Cursors.Default.Draw(g, new Rectangle(Cursor.Position, Cursors.Default.Size));
byte[] buffer = imageToByteArray(bitmap);
stream.Write(buffer, 0, buffer.Length);
}
public void EndConnection()
{
g.Dispose();
stream.Close();
stream.Dispose();
bitmap.Dispose();
timer.Enabled = false;
client.Close();
ConnectionClosed(this, new EventArgs());
return;
}
public Socket Socket
{
get
{
return client.Client;
}
}
byte[] imageToByteArray(System.Drawing.Image imageIn)
{
System.IO.MemoryStream ms = new System.IO.MemoryStream();
imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
return ms.ToArray();
}
}
/// <summary>
/// Represents all remote desktop runtime errors. Inherits from System.Exception.
/// </summary>
public class RemoteDesktopException : Exception
{
private string message;
private Exception ex;
/// <summary>
/// Constructor (+1 Overloads)
/// </summary>
/// <param name="error">The error message in string format.</param>
public RemoteDesktopException(string error)
{
message = error;
}
/// <summary>
/// Constructor (+1 Overloads)
/// </summary>
/// <param name="error">The error in System.Exception format.</param>
public RemoteDesktopException(Exception error)
{
ex = error;
}
public override string StackTrace
{
get
{
return base.StackTrace;
}
}
public override string HelpLink
{
get
{
return base.HelpLink;
}
set
{
base.HelpLink = value;
}
}
public override string Message
{
get
{
if (message != null)
{
return message;
}
else
{
return ex.Message;
}
}
}
}
public class DataEventArgs : EventArgs
{
private Image image;
public DataEventArgs(Image img)
{
image = img;
}
public System.Drawing.Image CurrentFrame
{
get
{
return image;
}
}
}
}
我在这里添加了
void timer_Tick(object sender, EventArgs e)
{
bitmap = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);
g = Graphics.FromImage(bitmap);
g.CopyFromScreen(0, 0, 0, 0, bitmap.Size);
Cursors.Default.Draw(g, new Rectangle(Cursor.Position, Cursors.Default.Size));
byte[] buffer = imageToByteArray(bitmap);
stream.Write(buffer, 0, buffer.Length);
stream.Flush();
}
那是你引用我放置stream.Flush（）子程序的地方吗？ * 因为它仍然不起作用。我还尝试将NoDelay属性设置为true。 *
答案 0 :(得分：4)
Image.FromStream的速度不太可能是你的问题。您的代码尝试每秒发送24帧。假设您的屏幕设置为1024 x 768，那就是786,432像素。使用24位颜色，大约2.25兆字节。沿着管道每秒24帧将是每秒54兆字节。
您的imageToByteArray方法会创建一个GIF，它将压缩一些。你得到的字节数组有多大？也就是说，在timer_tick方法中，您有：
byte[] buffer = imageToByteArray(bitmap);
stream.Write(buffer, 0, buffer.Length);
buffer.Length的价值是什么？
由于TCP开销，千兆网络将为您提供每秒少于100兆字节的内容。我怀疑你在这里遇到了网络限制。
通常，传输视频的应用程序（实际上是您正在做的事情）会进行差异压缩。他们弄清楚哪些像素已经改变，只发送那些像素。这大大降低了网络带宽。如果你真的想要24 FPS和任何尺寸的屏幕，你可能不得不做这样的事情。
答案 1 :(得分：1)
你不是在服务器端刷新流吗？尝试在服务器代码中调用Stream.Flush（）。这听起来像客户端正在等待更多数据来完成图像，但它仍然位于服务器流的缓冲区中。