仅在Visual Studio中无法解析的外部符号

我是c++编程的初学者(使用PHP多年)，并且在获得Visual Studio Express 2013编译一些在Xcode和Eclipse中都能正常工作的代码时遇到了一些麻烦。

是这样的。我的目标是使用SDL 2.0为手机和平板电脑创造一款游戏。我在Mac上工作(使用Windows的VM)，到目前为止已经成功地在Xcode和Eclipse中获得了初始测试项目。这两个项目都链接到使用Xcode创建的公共库(用于跨平台开发，所以我为所有平台编写了一次代码)。我现在正在尝试添加适当的Visual Studio项目，以便我也可以为Windows 8/WP8编译它。

按照这里的说明，我已经成功地在该页上进行了基本测试，证明SDL在Windows 8中正常工作。然而，我现在正在努力将我的公共库链接到Visual Studio中的项目，这一直给我错误。首先是代码。

main.cpp

#include "SDL.h"
#include "rectangles.h"
#include <time.h>
#define SCREEN_WIDTH 320
#define SCREEN_HEIGHT 480
int main(int argc, char *argv[])
{
    SDL_Window *window;
    SDL_Renderer *renderer;
    int done;
    SDL_Event event;
    /* initialize SDL */
    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        printf("Could not initialize SDLn");
        return 1;
    }
    /* seed random number generator */
    srand(time(NULL));
    /* create window and renderer */
    window =
        SDL_CreateWindow(NULL, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT,
                         SDL_WINDOW_OPENGL);
    if (!window) {
        printf("Could not initialize Windown");
        return 1;
    }
    renderer = SDL_CreateRenderer(window, -1, 0);
    if (!renderer) {
        printf("Could not create renderern");
        return 1;
    }
    Rectangles rectangles(SCREEN_WIDTH, SCREEN_HEIGHT);
    /* Enter render loop, waiting for user to quit */
    done = 0;
    while (!done) {
        while (SDL_PollEvent(&event)) {
            if (event.type == SDL_QUIT) {
                done = 1;
            }
        }

        rectangles.render(renderer);
        SDL_Delay(1);
    }
    /* shutdown SDL */
    SDL_Quit();
    return 0;
}

rectangles.h

#ifndef RECTANGLES_H
#define RECTANGLES_H
class Rectangles {
public:
    int screenWidth;
    int screenHeight;
    Rectangles(int width, int height);
    void render(SDL_Renderer *renderer);
    int randomInt(int min, int max);
};
#endif

rectangles.cpp

#include "SDL.h"
#include "Rectangles.h"
Rectangles::Rectangles(int width, int height)
{
    screenWidth = width;
    screenHeight = height;
    SDL_Log("Initializing rectangles!");
}
int Rectangles::randomInt(int min, int max)
{
    return min + rand() % (max - min + 1);
}
void Rectangles::render(SDL_Renderer *renderer)
{
    Uint8 r, g, b;
    /* Clear the screen */
    SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
    SDL_RenderClear(renderer);
    /*  Come up with a random rectangle */
    SDL_Rect rect;
    rect.w = randomInt(64, 128);
    rect.h = randomInt(64, 128);
    rect.x = randomInt(0, screenWidth);
    rect.y = randomInt(0, screenHeight);
    /* Come up with a random color */
    r = randomInt(50, 255);
    g = randomInt(50, 255);
    b = randomInt(50, 255);
    SDL_SetRenderDrawColor(renderer, r, g, b, 255);
    /*  Fill the rectangle in the color */
    SDL_RenderFillRect(renderer, &rect);
    /* update screen */
    SDL_RenderPresent(renderer);
}

我使用的代码是从使用SDL的教程略微修改的。我将用于绘制矩形的部分从main.cpp中的函数移动到它们自己的类中。这在Xcode (iOS)和Eclipse (Android)上都可以很好地编译和运行。我将矩形文件的位置添加到Visual Studio中的"附加包含目录"选项中，但它给出了以下错误:

Error   2   error LNK2019: unresolved external symbol "public: __thiscall Rectangles::Rectangles(int,int)" (??0Rectangles@@QAE@HH@Z) referenced in function _SDL_main   Z:DesktopSDLWinRTApplicationSDLWinRTApplicationmain.obj SDLWinRTApplication
Error   3   error LNK2019: unresolved external symbol "public: void __thiscall Rectangles::render(struct SDL_Renderer *)" (?render@Rectangles@@QAEXPAUSDL_Renderer@@@Z) referenced in function _SDL_main    Z:DesktopSDLWinRTApplicationSDLWinRTApplicationmain.obj SDLWinRTApplication
Error   4   error LNK1120: 2 unresolved externals   Z:DesktopSDLWinRTApplicationDebugSDLWinRTApplicationSDLWinRTApplication.exe    SDLWinRTApplication

我看了几个答案，表明这是我的代码有问题，但我看不出我做错了什么?或者有一个额外的步骤，我需要在Visual Studio中得到这个工作?

最终目标是每个平台都有单独的项目，调用一个真正的"游戏"存在的公共库，这样我就不用为每个平台来回复制文件了。多谢。

编辑:根据建议，我再次尝试将rectangles.cpp文件添加到Visual Studio中的项目解决方案中。然而，我得到以下错误，我不能使头或尾

Error   2   error LNK2038: mismatch detected for 'vccorlib_lib_should_be_specified_before_msvcrt_lib_to_linker': value '1' doesn't match value '0' in MSVCRTD.lib(appinit.obj)  Z:DesktopSDLWinRTApplicationSDLWinRTApplicationvccorlibd.lib(compiler.obj)  SDLWinRTApplication
Error   3   error LNK2005: ___crtWinrtInitType already defined in MSVCRTD.lib(appinit.obj)  Z:DesktopSDLWinRTApplicationSDLWinRTApplicationvccorlibd.lib(compiler.obj)  SDLWinRTApplication
Error   4   error LNK1169: one or more multiply defined symbols found   Z:DesktopSDLWinRTApplicationDebugSDLWinRTApplicationSDLWinRTApplication.exe    SDLWinRTApplication

EDIT2:如果我从"附加包含目录"中删除对rectangles.h位置的引用，并将rectangles.h与rectangles.cpp文件一起添加到项目解决方案中，那么我得到:

Error   1   error C1083: Cannot open include file: 'Rectangles.h': No such file or directory    z:desktopsdlwinrtapplicationsdlwinrtapplicationmain.cpp 8   1   SDLWinRTApplication

根据这里的问题，Visual Studio应该能够找到头文件时，它被添加到项目根?