'int WinMain' 重新声明为不同类型的符号

Question

我在使用 CODEBLOCKS (WinApi) 和 WINDOWS SDK 执行 CPP 中的代码时遇到了麻烦。 我的代码：

#if defined(UNICODE) && !defined(_UNICODE)
    #define _UNICODE
#elif defined(_UNICODE) && !defined(UNICODE)
    #define UNICODE
#endif

#include <tchar.h>
#include <windows.h>
#include <string>
#include <windows.h>
#include <stdlib.h>
#include <string.h>
#include <tchar.h>
#include <math.h>
#include <windowsx.h>


#define IDT_TIMER1      151L
#define NUM 1000
#define TWOPI (2*3.14159)

static TCHAR szWindowClass[] = _T("DesktopApp");
static TCHAR szTitle[] = _T("Curbe");
POINT apt[4];
POINT apt1[4];// definim variabilele globale
RECT r;
HINSTANCE hInst;

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
void InitBezierParams(); // Initializam punctele pentru Bezier

int CALLBACK WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPSTR  lpCmdLine, _In_ int  nCmdShow) {
    WNDCLASSEX wcex;
    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = WndProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.hIcon = LoadIcon(hInstance, IDI_APPLICATION);
    wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wcex.lpszMenuName = NULL;
    wcex.lpszClassName = szWindowClass;
    wcex.hIconSm = LoadIcon(wcex.hInstance, IDI_APPLICATION);

    if (!RegisterClassEx(&wcex)) {
        MessageBox(NULL,
            _T("Call to RegisterClassEx failed!"),
            _T("Windows Desktop Guided Tour"),
            NULL);
        return 1;
    }
    hInst = hInstance;

    HWND hWnd = CreateWindow(
        szWindowClass,
        szTitle,
        WS_OVERLAPPEDWINDOW, 500, 500, 700, 500,
        NULL,
        NULL,
        hInstance,
        NULL
    );

    if (!hWnd) {
        MessageBox(NULL,
            _T("Call to CreateWindow failed!"),
            _T("Windows Desktop Guided Tour"),
            NULL);
        return 1;
    }
    InitBezierParams(); // Chemam functia care initializeaza pentru prima data punctele curbei Bezier
    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);

    MSG msg;

    while (GetMessage(&msg, NULL, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return (int)msg.wParam;
}

void DrawBezier(HDC hdc, POINT apt[]) {
    // Draw Bessel function call system
    PolyBezier(hdc, apt, 4);
    MoveToEx(hdc, apt[0].x, apt[0].y, NULL);
    LineTo(hdc, apt[1].x, apt[1].y);
    MoveToEx(hdc, apt[2].x, apt[2].y, NULL);
    LineTo(hdc, apt[3].x, apt[3].y);
}

// functia care initializeaza punctele
void InitBezierParams() {

    apt1[0].x = 220; apt1[0].y = 210;
    apt1[1].x = 260; apt1[1].y = 20;
    apt1[2].x = 360; apt1[2].y = 290;
    apt1[3].x = 420; apt1[3].y = 210;

}

POINT rotate_point(float cx, float cy, float angle, POINT p) {
    float s = sin(angle);
    float c = cos(angle);

    // translate point back to origin:
    p.x -= cx;
    p.y -= cy;

    // rotate point
    float xnew = p.x * c - p.y * s;
    float ynew = p.x * s + p.y * c;

    // translate point back:
    p.x = xnew + cx;
    p.y = ynew + cy;
    return p;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    int i, j;
    static int cxClient, cyClient;
    static POINT apt[4];
    PAINTSTRUCT ps;
    HDC hdc;
    TCHAR greeting[] = _T("Curba Besier prin functii GDI");
    TCHAR greeting1[] = _T("Curba Besier prin functii matematice");

    switch (message) {

    case WM_SIZE: {
        cxClient = LOWORD(lParam);
        cyClient = HIWORD(lParam);
        //re the starting points, a first control point, the second control point.End
        apt[0].x = cxClient / 4;
        apt[0].y = cyClient / 2;
        apt[1].x = cxClient / 2;
        apt[1].y = cyClient / 4;
        apt[2].x = cxClient / 2;
        apt[2].y = 3 * cyClient / 4;
        apt[3].x = 3 * cxClient / 4;
        apt[3].y = cyClient / 2;
        return 0;
    }

    case WM_LBUTTONDOWN: {
    case WM_RBUTTONUP: {
    case WM_MOUSEMOVE: {
        // Left or right can draw
        if (wParam & MK_LBUTTON || wParam & MK_RBUTTON)
        {
            hdc = GetDC(hWnd);

            // draw from Bayesian curve defined function

            SelectObject(hdc, GetStockObject(WHITE_PEN));
            // Desenarea curbei prin funtie GDI
            DrawBezier(hdc, apt);
            // Left first control point
            if (wParam & MK_LBUTTON){
                apt[1].x = LOWORD(lParam);
                apt[1].y = HIWORD(lParam);
            }
            // Right control of the second control point
            if (wParam & MK_RBUTTON){
                apt[2].x = LOWORD(lParam);
                apt[2].y = HIWORD(lParam);
            }
            if (wParam & MK_RBUTTON)
            {
                apt[2].x = LOWORD(lParam);
                apt[2].y = HIWORD(lParam);
            }

            // replaced with custom brushes
            SelectObject(hdc, CreatePen(PS_DOT, 0, RGB(255, 0, 0)));
            // draw the curve
            DrawBezier(hdc, apt);
            ReleaseDC(hWnd, hdc);
        }
        return 0;
    }}}

    case WM_KEYDOWN: {

        //deplasarea punctului de control
        if (GetAsyncKeyState(VK_CONTROL))
        {
            switch (wParam)
            {
            case VK_LEFT:
                apt1[2].x -= 10;
                break;
            case VK_RIGHT:
                apt1[2].x += 6;
                break;
            case VK_UP:
                apt1[2].y -= 10;
                break;
            case VK_DOWN:
                apt1[2].y += 6;
                break;
            }
        }
        else
        {
            if (GetAsyncKeyState(VK_SPACE))
            {
                switch (wParam)
                {
                case VK_LEFT:
                {
                    for (size_t i = 0; i < 4; i++)
                    {
                        apt1[i].x--;
                    }
                }
                break;
                case VK_RIGHT:
                {
                    for (size_t i = 0; i < 4; i++)
                    {
                        apt1[i].x++;
                    }
                }
                break;
                case VK_UP:
                {
                    for (size_t i = 0; i < 4; i++)
                    {
                        apt1[i].y--;
                    }
                }
                break;
                case VK_DOWN:
                {
                    for (size_t i = 0; i < 4; i++)
                    {
                        apt1[i].y++;
                    }
                }
                break;
                }
            }
            else
            {
                if (GetAsyncKeyState(VK_SHIFT)) {
                    switch (wParam)
                    {

                    case VK_LEFT:
                        apt1[0] = rotate_point(300, 300, -100, apt1[0]);
                        apt1[1] = rotate_point(300, 300, -100, apt1[1]);
                        apt1[2] = rotate_point(300, 300, -100, apt1[2]);
                        apt1[3] = rotate_point(300, 300, -100, apt1[3]);

                        break;

                    case VK_RIGHT:

                        apt1[0] = rotate_point(300, 300, 100, apt1[0]);
                        apt1[1] = rotate_point(300, 300, 100, apt1[1]);
                        apt1[2] = rotate_point(300, 300, 100, apt1[2]);
                        apt1[3] = rotate_point(300, 300, 100, apt1[3]);

                        break;

                    }
                }
                else {
                    switch (wParam)
                    {
                    case VK_LEFT:
                        apt1[1].x -= 10;
                        break;
                    case VK_RIGHT:
                        apt1[1].x += 6;
                        break;
                    case VK_UP:
                        apt1[1].y -= 10;
                        break;
                    case VK_DOWN:
                        apt1[1].y += 6;

                        break;


                    case VK_TAB:
                        POINT p;
                        if (GetCursorPos(&p))
                        {
                            //cursor position now in p.x and p.y
                            apt1[1].x = p.x;
                            apt1[1].y = p.y;
                        }



                        break;
                    }
                }
            }
        }
        InvalidateRect(hWnd, NULL, TRUE);
        break;

    }

    case WM_PAINT: {
        hdc = BeginPaint(hWnd, &ps);

        SetTextColor(hdc, RGB(50, 70, 70));
        SetBkMode(hdc, TRANSPARENT);
        TextOut(hdc, 10, 10, greeting1, _tcslen(greeting1));
        PolyBezier(hdc, apt1, 4);

        SetTextColor(hdc, RGB(50, 70, 70));
        SetBkMode(hdc, TRANSPARENT);
        TextOut(hdc, 300, 10, greeting, _tcslen(greeting));

        {//desenare curba bezier dupa formula
            int x[4] = { 20, 60, 160, 220 };
            int y[4] = { 110, 20, 190, 110 };
            double xu, yu;
            for (double u = 0.0; u <= 1.0; u += 0.0001)
            {
                xu = (pow(1 - u, 3) * x[0] + 3 * u * pow(1 - u, 2) * x[1] + 3 * pow(u, 2) * (1 - u) * x[2] + pow(u, 3) * x[3]);
                yu = pow(1 - u, 3) * y[0] + 3 * u * pow(1 - u, 2) * y[1] + 3 * pow(u, 2) * (1 - u) * y[2] + pow(u, 3) * y[3];
                SetPixel(hdc, (int)xu, (int)yu, RGB(125, 120, 235));
            }
        }

        EndPaint(hWnd, &ps);
        break;
    }

    case WM_DESTROY: {
        PostQuitMessage(0);
        break;
    }

    default: {
        return DefWindowProc(hWnd, message, wParam, lParam);
        break;
    }

           return 0;
    }

}

我得到的错误：

||=== Build: Debug in Lab3 (compiler: GNU GCC Compiler) ===|
C:\Users\Lil-Dredd\Desktop\Lab_PW\Lab3\main.cpp|32|warning: '__stdcall__' attribute only applies to function types [-Wattributes]|
C:\Users\Lil-Dredd\Desktop\Lab_PW\Lab3\main.cpp|32|error: 'int WinMain' redeclared as different kind of symbol|
c:\mingw\include\winbase.h|1263|note: previous declaration 'int WinMain(HINSTANCE, HINSTANCE, LPSTR, int)'|
C:\Users\Lil-Dredd\Desktop\Lab_PW\Lab3\main.cpp|32|error: '_In_' was not declared in this scope|
C:\Users\Lil-Dredd\Desktop\Lab_PW\Lab3\main.cpp|32|error: '_In_opt_' was not declared in this scope|
C:\Users\Lil-Dredd\Desktop\Lab_PW\Lab3\main.cpp|32|error: '_In_' was not declared in this scope|
C:\Users\Lil-Dredd\Desktop\Lab_PW\Lab3\main.cpp|32|error: '_In_' was not declared in this scope|
C:\Users\Lil-Dredd\Desktop\Lab_PW\Lab3\main.cpp|23|warning: 'szTitle' defined but not used [-Wunused-variable]|
C:\Users\Lil-Dredd\Desktop\Lab_PW\Lab3\main.cpp|22|warning: 'szWindowClass' defined but not used [-Wunused-variable]|
||=== Build failed: 5 error(s), 3 warning(s) (0 minute(s), 0 second(s)) ===|

我试图在 stackoverflow 上找到任何信息和修复，但我什至什么都没有。 请帮忙...

代码含义： 执行后： https://prnt.sc/10v4p74 Exp: 我要做 3 个 bezeir 路缘，其中一个应该用键盘操作

Answer 1

• 启动代码块。
• 文件 -> 新建 -> 项目
• Win32 图形用户界面项目。 不要选择控制台应用程序！
• 基于选择框架（可能无关紧要）
• 选择名称和路径。 选择 gcc 作为编译器。
• 将代码原样复制到 main.cpp 中。
• 构建、编译和运行。

---

出现神秘错误消息的原因是，如果您选择了错误的项目类型，例如不是明确的 Win32 API 项目，那么编译器库可能在内部启动代码的其他地方有一个 WinMain。 所以你得到一个重复的 function 冲突 - WinMain 重新声明。