【软件设计师备考 专题 】C、C++、Java、Visual Basic、Visual C++等语言的基础知识和应用（三）

class Person {
private:
    int age;
    string name;
public:
    Person(int a, string n) {
        age = a;
        name = n;
    }
    void display() {
        cout << "Name: " << name << endl;
        cout << "Age: " << age << endl;
    }
};

Person p(25, "John");
p.display();

class Animal {
protected:
    int age;
public:
    Animal(int a) {
        age = a;
    }
    virtual void sound() {
        cout << "Animal sound" << endl;
    }
};
class Dog : public Animal {
public:
    Dog(int a) : Animal(a) {}
    void sound() {
        cout << "Dog sound" << endl;
    }
};

Animal* animal = new Dog(3);
animal->sound(); // 调用的是Dog类的sound函数

int num = 10;
if (num > 0) {
    cout << "Positive number" << endl;
} else if (num < 0) {
    cout << "Negative number" << endl;
} else {
    cout << "Zero" << endl;
}

for (int i = 0; i < 5; i++) {
    cout << i << endl;
}
int i = 0;
while (i < 5) {
    cout << i << endl;
    i++;
}
int i = 0;
do {
    cout << i << endl;
    i++;
} while (i < 5);

#include <afxwin.h>
class CMyApp : public CWinApp {
public:
    virtual BOOL InitInstance() {
        CFrameWnd* pFrame = new CFrameWnd;
        pFrame->Create(NULL, _T("My App"));
        m_pMainWnd = pFrame;
        pFrame->ShowWindow(SW_SHOW);
        pFrame->UpdateWindow();
        return TRUE;
    }
};
CMyApp theApp;

#include <d3d9.h>
LPDIRECT3D9 d3d;
LPDIRECT3DDEVICE9 d3dDevice;
void InitD3D(HWND hWnd) {
    d3d = Direct3DCreate9(D3D_SDK_VERSION);
    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory(&d3dpp, sizeof(d3dpp));
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3d->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
        D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &d3dDevice);
}
void RenderFrame() {
    d3dDevice->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 255), 1.0f, 0);
    d3dDevice->BeginScene();
    // 渲染代码
    d3dDevice->EndScene();
    d3dDevice->Present(NULL, NULL, NULL, NULL);
}
void CleanD3D() {
    d3dDevice->Release();
    d3d->Release();
}
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    switch (message) {
        case WM_DESTROY:
            CleanD3D();
            PostQuitMessage(0);
            return 0;
        case WM_PAINT:
            RenderFrame();
            ValidateRect(hWnd, NULL);
            return 0;
    }
    return DefWindowProc(hWnd, message, wParam, lParam);
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
    HWND hWnd;
    WNDCLASSEX wc;
    ZeroMemory(&wc, sizeof(WNDCLASSEX));
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WindowProc;
    wc.hInstance = hInstance;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
    wc.lpszClassName = _T("WindowClass");
    RegisterClassEx(&wc);
    hWnd = CreateWindowEx(NULL, _T("WindowClass"), _T("My First Direct3D Program"),
        WS_OVERLAPPEDWINDOW, 0, 0, 800, 600, NULL, NULL, hInstance, NULL);
    InitD3D(hWnd);
    ShowWindow(hWnd, nCmdShow);
    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}