在应用程序不在前台时获得精确的鼠标移动增量

Question

我正在尝试弄清楚如何从 Win32 API 获取精确的鼠标移动信息，这种方式在我的应用程序未获得焦点时仍然有效。到目前为止，我已经尝试了三种不同的方法：

通过 SetWindowsHookEx 和 WH_MOUSE_LL 注册 WM_MOUSEMOVE 事件。这在应用程序处于后台时有效，但 returns 屏幕坐标精度相对较低。此外，指针弹道学应用于这些值，使它们不太适合我的目的。
循环调用GetCursorPos。这也适用于后台，但它再次应用 returns 低分辨率屏幕坐标和指针加速。
通过 RegisterRawInputDevices 注册原始输入，然后观察 WM_INPUT 事件（调用 GetRawInputData 以实际访问数据）。这个 - 至少，根据文档 - returns 以本地鼠标单位坐标，因此它尽可能精确。不幸的是，这仅在应用程序获得焦点时有效。 The docs 说：

An application can receive data when it is in the foreground and when it is in the background.

但我还没有看到任何证实这些说法的行为。

因为我的主要问题是关于第三个选项，所以我在下面包含了我的代码。

那么，即使应用程序没有焦点，我如何才能以一种有效的方式访问本机鼠标值？是否需要额外的配置才能使 #3 工作，或者是否有其他选项？

#include "stdafx.h"
// ...

#define MAX_LOADSTRING 100

// Global Variables:
HINSTANCE hInst;                                // current instance
WCHAR szTitle[MAX_LOADSTRING];                  // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING];            // the main window class name

HWND mainWindow;

// Forward declarations of functions included in this code module:
ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPWSTR    lpCmdLine,
                     _In_ int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // TODO: Place code here.

    // Initialize global strings
    LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadStringW(hInstance, IDC_MOUSETEST, szWindowClass, MAX_LOADSTRING);
    MyRegisterClass(hInstance);

    // Perform application initialization:
    if (!InitInstance (hInstance, nCmdShow))
    {
        return FALSE;
    }

    HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_MOUSETEST));

    MSG msg;

    // Main message loop:
    while (GetMessage(&msg, nullptr, 0, 0))
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return (int) msg.wParam;
}



//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEXW wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);

    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = WndProc;
    wcex.cbClsExtra     = 0;
    wcex.cbWndExtra     = 0;
    wcex.hInstance      = hInstance;
    wcex.hIcon          = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_MOUSETEST));
    wcex.hCursor        = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName   = MAKEINTRESOURCEW(IDC_MOUSETEST);
    wcex.lpszClassName  = szWindowClass;
    wcex.hIconSm        = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    return RegisterClassExW(&wcex);
}

//
//   FUNCTION: InitInstance(HINSTANCE, int)
//
//   PURPOSE: Saves instance handle and creates main window
//
//   COMMENTS:
//
//        In this function, we save the instance handle in a global variable and
//        create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   hInst = hInstance; // Store instance handle in our global variable

   mainWindow = CreateWindowW(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW | RIDEV_INPUTSINK,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, nullptr, nullptr, hInstance, nullptr);

   if (!mainWindow)
   {
      return FALSE;
   }

   ShowWindow(mainWindow, nCmdShow);
   UpdateWindow(mainWindow);

   // Register for raw input events

   RAWINPUTDEVICE targetDevice = { 0x01, 0x02, 0, mainWindow };
   BOOL registerRawSuccess = RegisterRawInputDevices(&targetDevice, 1, sizeof(RAWINPUTDEVICE));

   if (!registerRawSuccess)
       return FALSE;

   return TRUE;
}

//
//  FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  PURPOSE:  Processes messages for the main window.
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    // ...
    case WM_INPUT :
        {
            UINT dwSize = 40;
            static BYTE lpb[40];

            if (GetRawInputData((HRAWINPUT)lParam, RID_INPUT,
                NULL, &dwSize, sizeof(RAWINPUTHEADER)) == -1)
            {
                // TODO: Handle this... something broke
            }

            UINT result = GetRawInputData((HRAWINPUT)lParam, RID_INPUT,
                lpb, &dwSize, sizeof(RAWINPUTHEADER));

            RAWINPUT* raw = (RAWINPUT*)lpb;

            if (raw->header.dwType == RIM_TYPEMOUSE)
            {
                // Use raw->data.mouse.lLastX and raw->data.mouse.lLastY
            }
            break;
        }
    // ...
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

Answer 1

使用原始输入 API 时，如果您想在后台运行时接收 WM_INPUT 消息，请指定 RIDEV_INPUTSINK 标志：

If set, this enables the caller to receive the input even when the caller is not in the foreground. Note that hwndTarget must be specified.

更改此行：

RAWINPUTDEVICE targetDevice = { 0x01, 0x02, 0, mainWindow };

为此：

RAWINPUTDEVICE targetDevice = { 0x01, 0x02, RIDEV_INPUTSINK, mainWindow };

在应用程序不在前台时获得精确的鼠标移动增量

Getting precise mouse movement deltas while application is not in foreground

c++

windows

mouse

winapi

input