【转】用C#调用Windows API向指定窗口发送

一、调用Windows API。
　C#下调用Windows API方法如下：
　1、引入命名空间：using System.Runtime.InteropServices;
　2、引用需要使用的方法，格式：[DllImport("DLL文件")]方法的声明;

[DllImport("user32.dll")]private static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
[DllImport("user32.dll")]private static extern bool SetForegroundWindow(IntPtr hWnd);
[DllImport("user32.dll")]private static extern IntPtr FindWindow(string lpClassName,string lpWindowName);
[DllImport("user32.dll")]private static extern int SendMessage(IntPtr hWnd,int Msg,int wParam,int lParam);
[DllImport("user32.dll")]private static extern bool SetCursorPos(int X, int Y);
[DllImport("user32.dll")]private static extern void mouse_event(int dwFlags, int dx, int dy, int dwData, int dwExtraInfo);
[DllImport("user32.dll")]private static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, uint dwExtraInfo);
[DllImport("user32.dll")]private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndlnsertAfter, int X, int Y, int cx, int cy, uint Flags);
//ShowWindow参数
private const int SW_SHOWNORMAL = 1;
private const int SW_RESTORE = 9;
private const int SW_SHOWNOACTIVATE = 4;
//SendMessage参数
private const int WM_KEYDOWN = 0X100;
private const int WM_KEYUP = 0X101;
private const int WM_SYSCHAR = 0X106;
private const int WM_SYSKEYUP = 0X105;
private const int WM_SYSKEYDOWN = 0X104;
private const int WM_CHAR = 0X102;

二、找到目标窗口
1)、根据窗口的标题得到句柄

IntPtr myIntPtr = FindWindow(null,"窗口名"); //null为类名，可以用Spy++得到，也可以为空
ShowWindow(myIntPtr, SW_RESTORE); //将窗口还原
SetForegroundWindow(myIntPtr); //如果没有ShowWindow，此方法不能设置最小化的窗口

2)、遍历所有窗口得到句柄
1 定义委托方法CallBack，枚举窗口API（EnumWindows），得到窗口名API（GetWindowTextW）和得到窗口类名API（GetClassNameW）

public delegate bool CallBack(int hwnd, int lParam);
[DllImport("user32")]public static extern int EnumWindows(CallBack x, int y);
[DllImport("user32.dll")]private static extern int GetWindowTextW(IntPtr hWnd, [MarshalAs(UnmanagedType.LPWStr)]StringBuilder lpString, int nMaxCount);
[DllImport("user32.dll")]private static extern int GetClassNameW(IntPtr hWnd, [MarshalAs(UnmanagedType.LPWStr)]StringBuilder lpString, int nMaxCount);

2 调用EnumWindows遍历窗口

CallBack myCallBack = new CallBack(Recall);
EnumWindows(myCallBack, 0);

3 回调方法Recall

public bool Recall(int hwnd, int lParam)
{
　StringBuilder sb = new StringBuilder(256);
　IntPtr PW = new IntPtr(hwnd);

　GetWindowTextW(PW,sb,sb.Capacity); //得到窗口名并保存在strName中
　string strName = sb.ToString();

　GetClassNameW(PW,sb,sb.Capacity); //得到窗口类名并保存在strClass中
　string strClass = sb.ToString();

　if (strName.IndexOf("窗口名关键字") >= 0 && strClass.IndexOf("类名关键字") >= 0)
　{
　　return false; //返回false中止EnumWindows遍历
　}
　else
　{
　　return true; //返回true继续EnumWindows遍历
　}
}

3)、打开窗口得到句柄
1 定义设置活动窗口API（SetActiveWindow），设置前台窗口API（SetForegroundWindow）

[DllImport("user32.dll")]static extern IntPtr SetActiveWindow(IntPtr hWnd);
[DllImport("user32.dll")][return: MarshalAs(UnmanagedType.Bool)]static extern bool SetForegroundWindow(IntPtr hWnd);

2 打开窗口

Process proc = Process.Start(@"目标程序路径");
SetActiveWindow(proc.MainWindowHandle);
SetForegroundWindow(proc.MainWindowHandle);

三、向指定的窗口输入数据
1 利用发送消息API（SendMessage）向窗口发送数据

InputStr(myIntPtr, _GameID); //输入游戏ID
SendMessage(myIntPtr, WM_SYSKEYDOWN, 0X09, 0); //输入TAB（0x09）
SendMessage(myIntPtr, WM_SYSKEYUP, 0X09, 0);
InputStr(myIntPtr, _GamePass); //输入游戏密码
SendMessage(myIntPtr, WM_SYSKEYDOWN, 0X0D, 0); //输入ENTER（0x0d）
SendMessage(myIntPtr, WM_SYSKEYUP, 0X0D, 0);

/// <summary>
/// 发送一个字符串
/// </summary>
/// <param name="myIntPtr">窗口句柄</param>
/// <param name="Input">字符串</param>
public void InputStr(IntPtr myIntPtr, string Input)
{
　byte[] ch = (ASCIIEncoding.ASCII.GetBytes(Input));
　for (int i = 0; i < ch.Length; i++)
　{
　　SendMessage(PW, WM_CHAR, ch, 0);
　}
}

2 利用鼠标和键盘模拟向窗口发送数据

SetWindowPos(PW, (IntPtr)(-1), 0, 0, 0, 0, 0x0040 | 0x0001); //设置窗口位置
SetCursorPos(476, 177); //设置鼠标位置
mouse_event(0x0002, 0, 0, 0, 0); //模拟鼠标按下操作
mouse_event(0x0004, 0, 0, 0, 0); //模拟鼠标放开操作
SendKeys.Send(_GameID);   //模拟键盘输入游戏ID
SendKeys.Send("{TAB}"); //模拟键盘输入TAB
SendKeys.Send(_GamePass); //模拟键盘输入游戏密码
SendKeys.Send("{ENTER}"); //模拟键盘输入ENTER

另：上面还提到了keybd_event方法，用法和mouse_event方法类似，作用和SendKeys.Send一样。

【转】http://www.51testing.com/html/61/175761-227073.html