WinMain
每个Windows程序都包含一个名为WinMain或wWinMain的入口点函数。注意两者中第三个参数是不一样的
int WINAPI wWinMain(
HINSTANCE hInstance,
HINSTANCE hPrevInstance,
PWSTR pCmdLine,
INT nCmdShow);
{
return 0;
}
INT WINAPI WinMain(
HINSTANCE hInstance,
HINSTANCE hPrevInstance,
PSTR lpCmdLine,
INT nCmdShow)
{
return 0;
}
函数类型INT后的WINAPI其实是可以省略的，但是省略之后将会有警告warning C4007: “WinMain”: 必须是“__stdcall”。
转到宏定义会发现
#define CALLBACK __stdcall
#define WINAPI __stdcall
CALLBACK和WINAPI都定义为了__stdcall，__stdcall表示一种调用约定，让编译器知道应当以Windows兼容的方式来产生机器指令（__stdcall官方解释）。
首先科普一下句柄，在Windows编程的基础中，一个句柄是指使用的一个唯一的整数值，即一个4字节(64位程序中为8字节)长的数值，来标识应用程序中的不同对象和同类中的不同的实例，诸如，一个窗口，按钮，图标，滚动条，输出设备，控件或者文件等。
- HINSTANCE类型的hInstance，表示“实例句柄”或“模块句柄”（h代表参数为handle），他唯一对应一个运行中的实例，只有运行中的程序实例，才有资格分配到实例句柄。一个应用程序可以运行多个实例，每运行一个实例，系统都会给该实例分配一个句柄值，并且通过hInstance传入WinMain中。
- HINSTANCE的hPrevInstance，表示当前实例的前一个实例句柄。在Win32环境下，没有任何意义。它用于16位Windows，但现在总是为零。只是在进行WinMain函数书写时需要传入一个参数。
- pCmdLine，包含命令行参数作为Unicode字符串，p表示指针，CmdLine表示命令行。
- nCmdShow，是一个标志，指示主应用程序窗口是否将被最小化，最大化或正常显示。
| 参数 | 值 | 描述 |
|---|---|---|
| SW_FORCEMINIMIZE | 11 | Minimizes a window, even if the thread that owns the window is not responding. This flag should only be used when minimizing windows from a different thread. |
| SW_HIDE | 0 | Hides the window and activates another window. |
| SW_MAXIMIZE | 3 | Maximizes the specified window. |
| SW_MINIMIZE | 6 | Minimizes the specified window and activates the next top-level window in the Z order. |
| SW_RESTORE | 9 | Activates and displays the window. If the window is minimized or maximized, the system restores it to its original size and position. An application should specify this flag when restoring a minimized window. |
| SW_SHOW | 5 | Activates the window and displays it in its current size and position. |
| SW_SHOWDEFAULT | 10 | Sets the show state based on the SW_ value specified in the STARTUPINFO structure passed to the CreateProcess function by the program that started the application. |
| SW_SHOWMAXIMIZED | 3 | Activates the window and displays it as a maximized window. |
| SW_SHOWMINIMIZED | 2 | Activates the window and displays it as a minimized window. |
| SW_SHOWMINNOACTIVE | 7 | Displays the window as a minimized window. This value is similar to SW_SHOWMINIMIZED, except the window is not activated. |
| SW_SHOWNA | 8 | Displays the window in its current size and position. This value is similar to SW_SHOW, except that the window is not activated. |
| SW_SHOWNOACTIVATE | 4 | Displays a window in its most recent size and position. This value is similar to SW_SHOWNORMAL, except that the window is not activated. |
| SW_SHOWNORMAL | 1 | Activates and displays a window. If the window is minimized or maximized, the system restores it to its original size and position. An application should specify this flag when displaying the window for the first time. |
我就懒得翻译了，大概应该看得懂
