局域网控制（二）——控制客户端

2、控制客户端

控制客户端主要还是通过在控制端发送一个消息指令到客户端，客户端在接受消息后执行该执行。本例中主要以模拟鼠标点击事件为例来说明这一实现过程，通过在控制端中PictureBox控件上点击图像的某个位置，然后将这一消息转换成指令发送至客户端，客户端在接受该指令后执行，具体实现过程如下：

1）将控制端控制转换成指令

在此模拟鼠标点击事件，所以发送至客户端的命令可采用如下格式：

光标X坐标,光标Y坐标,鼠标事件

其中，鼠标事件中用0表示没有任何鼠标点击事件，1表示单击，2表示双击、3表示点击鼠标右键。

要获取光标的坐标，可以通过鼠标在PictureBox控件上点击位置进行转换，如下：

MouseEventArgs mouseE = (MouseEventArgs)e;

int origWidth = ClientPictureBox.Image.Width;

int origHeight = ClientPictureBox.Image.Height;

int cursorX, cursorY;

cursorX = mouseE.X * origWidth / ClientPictureBox.Width;

cursorY = mouseE.Y * origHeight / ClientPictureBox.Height;

其中，origWidth表示传输的客户端界面原始宽度，origHeight表示客户端界面原始高度，ClientPictureBox为控制端中显示客户端界面的图像控件，cursorX和cursorY表示鼠标在客户端计算机上的位置。

于是，在ClientPictureBox控件的Click()事件中添加如下代码：

【控制端】:

private void ClientPictureBox_Click(object sender, EventArgs e)

{

if (ClientPictureBox.Image != null)

{

//将图片中的坐标位置转换成客户端桌面的坐标

MouseEventArgs mouseE = (MouseEventArgs)e;

int origWidth = ClientPictureBox.Image.Width;

int origHeight = ClientPictureBox.Image.Height;

int cursorX, cursorY;

cursorX = mouseE.X * origWidth / ClientPictureBox.Width;

cursorY = mouseE.Y * origHeight / ClientPictureBox.Height;

string message = cursorX.ToString() + "," + cursorY.ToString();

if (mouseE.Button.ToString() == "Left")

{

message += ",1";

}

else if (mouseE.Button.ToString() == "Right")

{

message += ",3";

}

SendMessage(message);

}

}

其中，SendMessage()函数为一个发生消息至客户端的函数，稍后将介绍。在ClientPictureBox控件的DoubleClick ()事件中添加如下代码：

【控制端】:

private void ClientPictureBox_DoubleClick(object sender, EventArgs e)

{

if (ClientPictureBox.Image != null)

{

//将图片中的坐标位置转换成客户端桌面的坐标

MouseEventArgs mouseE = (MouseEventArgs)e;

int origWidth = ClientPictureBox.Image.Width;

int origHeight = ClientPictureBox.Image.Height;

int cursorX, cursorY;

cursorX = mouseE.X * origWidth / ClientPictureBox.Width;

cursorY = mouseE.Y * origHeight / ClientPictureBox.Height;

string message = cursorX.ToString() + "," + cursorY.ToString() + ",2";

SendMessage(message);

}

}

2）发送指令至客户端

前面已经提到了SendMessage()这个函数，该函数主要实现向客户端发送消息，其定义如下：

【控制端】:

private void SendMessage(string message)

{

TcpClient client = new TcpClient();

Int32 port = Int32.Parse(portTextBox.Text);

client.Connect(IPAddress.Parse(IPAddressTextBox.Text), port);

if (client.Connected)

{

byte[] bytes = Encoding.ASCII.GetBytes(message);

NetworkStream stream = client.GetStream();

stream.Write(bytes, 0, bytes.Length);

stream.Close();

client.Close();

}

}

3）客户端接受指令

接受消息同样要采用TcpListener类来监听端口，一旦有数据传输过来时就接收，所以类似要在全局中定义变量：

【客户端】:

TcpListener tcpListener;

然后定义监听端口函数Listen()，当有数据传输过来时，将数据转换成String字符串，如下：

【客户端】:

private void Listen()

{

try

{

Int32 port = Int32.Parse(portTextBox.Text);

tcpListener = new TcpListener(port);

tcpListener.Start();

while (true)

{

TcpClient client = tcpListener.AcceptTcpClient();

NetworkStream stream = client.GetStream();

if (stream.CanRead)

{

string mouseEvent = "";

byte[] bytes = new byte[1024];

stream.Read(bytes, 0, bytes.Length);

mouseEvent = Encoding.ASCII.GetString(bytes);

//分解字符串

int i, mouseX, mouseY, mouseClick;

i = mouseEvent.IndexOf(",");

mouseX = int.Parse(Microsoft.VisualBasic.Strings.Left(mouseEvent, i));

mouseEvent = Microsoft.VisualBasic.Strings.Right(mouseEvent, mouseEvent.Length - i - 1);

i = mouseEvent.IndexOf(",");

mouseY = int.Parse(Microsoft.VisualBasic.Strings.Left(mouseEvent, i));

i = mouseEvent.IndexOf(",");

mouseEvent = Microsoft.VisualBasic.Strings.Right(mouseEvent, mouseEvent.Length - i - 1);

mouseClick = int.Parse(mouseEvent);

//设置鼠标

mouseClickEvent(mouseX, mouseY, mouseClick);

}

client.Close();

}

}

finally

{

tcpListener.Stop();

}

}

上述代码中，变量mouseEvent为控制端传输的指令，其格式为“光标X坐标,光标Y坐标,鼠标事件”，所以需要将其字符串进行分割，分割出光标X坐标、光标Y坐标和鼠标事件，然后使用mouseClickEvent()函数来执行该命令，关于这个执行鼠标命令的函数下面开始介绍。

4）执行鼠标命令

执行鼠标命令主要通过Windows API中的SetCursorPos()函数设置光标位置，mouse_event()函数来指定鼠标事件，所以首先需要在全局中引用这些函数，如下：

【客户端】:

[DllImport("user32.dll")]

private extern static bool SetCursorPos(int x, int y);

[DllImport("user32.dll")]

private static extern void mouse_event(MouseEventFlag flags, int dx, int dy, uint data, UIntPtr extraInfo);

enum MouseEventFlag : uint

{

Move = 0x0001,

LeftDown = 0x0002,

LeftUp = 0x0004,

RightDown = 0x0008,

RightUp = 0x0010,

MiddleDown = 0x0020,

MiddleUp = 0x0040,

XDown = 0x0080,

XUp = 0x0100,

Wheel = 0x0800,

VirtualDesk = 0x4000,

Absolute = 0x8000

}

然后定义执行鼠标命令的函数mouseClickEvent()，其代码如下：

【客户端】:

private void mouseClickEvent(int x, int y, int state)

{

SetCursorPos(x, y);

if (state == 0)

{

return;

}

else if (state == 1) //单击

{

mouse_event(MouseEventFlag.LeftDown | MouseEventFlag.LeftUp, x, y, 0, (UIntPtr)0);

}

else if (state == 2) //双击

{

mouse_event(MouseEventFlag.LeftDown | MouseEventFlag.LeftUp, x, y, 0, (UIntPtr)0);

mouse_event(MouseEventFlag.LeftDown | MouseEventFlag.LeftUp, x, y, 0, (UIntPtr)0);

}

else if (state == 3) //右键

{

mouse_event(MouseEventFlag.RightDown | MouseEventFlag.RightUp, x, y, 0, (UIntPtr)0);

}

}

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