我正在尝试执行以下操作之一
 1.打开所需程序并以编程方式按键
 2.找到程序的打开窗口并以编程方式按键
 (要么很好)

我尝试了很多SendKeys.SendWait(),PostMessage()和SendMessage()的实现失败.以下是我的代码片段

    //included all these for attempts 
    [DllImport("User32.dll")] 
    static extern IntPtr FindWindow(string lpClassName, string lpWindowName);  

    [DllImport("User32.dll")] 
    static extern int SetForegroundWindow(IntPtr hWnd);

    [DllImport("User32.Dll", EntryPoint = "PostMessageA")]
    static extern bool PostMessage(IntPtr hWnd, uint msg, int wParam, int lParam);

    [DllImport("user32.dll")]
    static extern byte VkKeyScan(char ch);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);

获取sendmessage / postmessage / sendkeys使用的窗口,变量的句柄

IntPtr ptrOBS = proc.Handle;//this works properly, proc is instantiated properly
//IntPtr ptrOBS = FindWindow(null, "Open Broadcaster Software v0.472b");
SetForegroundWindow(ptrOBS);
const UInt32 WM_CHAR = 0x0102;
const uint WM_KEYDOWN = 0x100;
const int VK_R = 0x52; // taken from http://msdn.microsoft.com/en-us/library/dd375731(v=vs.85).aspx
const int VK_S = 0x53;

SendMessage尝试：

SendMessage(ptrOBS, WM_KEYDOWN, (IntPtr)VK_R, (IntPtr)1);//tried both WM_CHAR and WM_KEYDOWN

PostMessage尝试：

string message = "rs";
bool sent = PostMessage(ptrOBS, WM_KEYDOWN, VkKeyScan(message[0]), 0);

SendKeys尝试：

SendKeys.SendWait("{r}");

在父窗口(应用程序)和子窗口上尝试SetFocus(由按键触发的按钮即可尝试发送)：

static void SetFocus(IntPtr hwndTarget, string childClassName)
    {
        // hwndTarget is the other app's main window 
        // ...
        IntPtr targetThreadID = GetWindowThreadProcessId(hwndTarget, IntPtr.Zero); //target thread id
        IntPtr myThreadID = GetCurrentThread(); // calling thread id, our thread id
        try
        {
            bool lRet = AttachThreadInput(myThreadID, targetThreadID, -1); // attach current thread id to target window

            // if it's not already in the foreground...
            lRet = BringWindowToTop(hwndTarget);
            SetForegroundWindow(hwndTarget);

            // if you know the child win class name do something like this (enumerate windows using Win API again)...
            IntPtr hwndChild = (IntPtr)1183492;//(IntPtr)EnumAllWindows(hwndTarget, childClassName).FirstOrDefault();

            if (hwndChild == IntPtr.Zero)
            {
                // or use keyboard etc. to focus, i.e. send keys/input...
                // SendInput (...);
                return;
            }

            // you can use also the edit control's hwnd or some child window (of target) here
            SetFocus(hwndChild); // hwndTarget);
            SendKeys.SendWait("{r}");
        }
        finally
        {
            SendKeys.SendWait("{r}");
            bool lRet = AttachThreadInput(myThreadID, targetThreadID, 0); //detach from foreground window
            SendKeys.SendWait("{r}");
        }
    }

对于NSGaga：

    string windowName = "Open Broadcaster Software v0.472b";
IntPtr outerPtr = FindWindow(null, windowName);
IntPtr ptrOBS = (IntPtr)527814;//button that im trying to trigger keypress on
SetForegroundWindow(outerPtr);
SetForegroundWindow(ptrOBS);
SetFocus(outerPtr, "OBSWindowClass");//SetFocus(ptrOBS, "Button");
const UInt32 WM_CHAR = 0x0102;
const int VK_R = 0x52; // taken from http://msdn.microsoft.com/en-us/library/dd375731(v=vs.85).aspx
const int VK_S = 0x53;

//SetForegroundWindow(ptrOBS);
System.Threading.Thread.Sleep(3000);
SendKeys.SendWait("{r}");
SendMessage(outerPtr, WM_KEYDOWN, (IntPtr)VK_R, (IntPtr)1);
PostMessage(outerPtr, WM_KEYDOWN, VkKeyScan('r'), 0);

解决方法:

为了让它发挥作用,有很多试验和错误
这里是我之前发布的一些代码,你可能想尝试一下(并附上一些更多的信息)……

Pinvoke SetFocus to a particular control

首先尝试设置焦点(使用提到的机制) – 然后使用SendKeys或SendInput.

这是SendInput的一些详细代码……

How to send a string to other application including Microsoft Word