(win32)句柄,消息循环

句柄 HANDLE

图标句柄HICON

光标句柄HCURSOR

窗口句柄HWND

应用程序实例句柄HINSTANCE

//消息队列的消息结构体

This structure contains message information from a thread's message queue.

typedef struct tagMSG {
  HWND hwnd; //句柄
  UINT message; //Unsigned Int 以WM_开头的宏作为消息的类型
  WPARAM wParam; //整数, 指示消息的附加信息
  LPARAM lParam; //整数, 指示消息的附加信息
  DWORD time; //32位整数, 指示消息传递的时间
  POINT pt; //消息传递的时候当前光标的位置
} MSG;

消息传递的宏, 以WM_开头

WM_message

WM_KEYDOWN

WM_LBUTTONDOWN

按下A键, 收到WM_CHAR消息, (message), 通过wParam 获取A键的ASCII码.

typedef struct tagPOINT {
  LONG x;
  LONG y;
} POINT;

int WINAPI WinMain(     

    HINSTANCE hInstance, // handle to current instance
    HINSTANCE hPrevInstance,
    LPSTR lpCmdLine, //commmand line
    int nCmdShow //show state 程序的现实状态.
);

LPSTR LP 表示LONG POINT 长指针, 指向字符串的长指针.

构建一个完整的窗口需要的四个操作步骤

设计一个窗口类

注册窗口类

创建窗口

显示及更新窗口

窗口类

typedef struct {
    UINT style; // 类的类型, 很多.
    WNDPROC lpfnWndProc; //接收函数指针, 回调函数.
    int cbClsExtra;//额外参数, 通常为0
    int cbWndExtra;//额外参数, 通常为0
    HINSTANCE hInstance;//当前实例
    HICON hIcon;//图标句柄使用LoadIcon()
    HCURSOR hCursor;//光标句柄LoadCursor()
    HBRUSH hbrBackground;//画刷句柄, 使用(HBRUSH)GetStockObject()
    LPCTSTR lpszMenuName;//长指针指向常量字符串, 设置菜单的名字.
    LPCTSTR lpszClassName;//长指针指向常量字符串, 窗口的名字.
} WNDCLASS, *PWNDCLASS;

注册窗口RegisterClass(&wndclass)

 

创建窗口

HWND hwnd;

HWND CreateWindow(     

    LPCTSTR lpClassName, //注册的窗口类的类名, 即lpszClassName
    LPCTSTR lpWindowName,//窗口的名字, 即窗口的标题
    DWORD dwStyle, // 窗口的类型.
    int x, // 窗口的x坐标, CW_USEDEFAULT
    int y, // 窗口的y坐标
    int nWidth, //窗口的宽度 CW_USEDEFAULT
    int nHeight, //窗口的高度
    HWND hWndParent, // 指示父窗口的句柄
    HMENU hMenu, //菜单的句柄
    HINSTANCE hInstance, //当前应用程序的句柄
    LPVOID lpParam // 作为WM_CREATE的参数
);

显示窗口及更新窗口

ShowWindow(hwnd, SW_SHOWNORMAL)

UpdateWindow(hwnd)

消息循环!!!

 

BOOL GetMessage(     

    LPMSG lpMsg, // 消息
    HWND hWnd, // 获取哪一个窗口的信息, NULL 为调用线程的任何窗口的信息
    UINT wMsgFilterMin, // 最小的消息值
    UINT wMsgFilterMax // 最大的消息值
);

 

MSG msg;

while (GetMessage(&msg, NULL, 0, 0)

{

TranslateMessage(&msg); //转换消息

DispatchMessage(&msg);//将消息交给回调函数处理

}

回调函数 , 窗口过程函数

LRESULT CALLBACK WindowProc(     

    HWND hwnd,
    UINT uMsg,
    WPARAM wParam,
    LPARAM lParam
)

{

HDC hdc;

PAINTSTRUCT ps;

switch (uMsg)

{

case WM_CHAR:

char szChar[20];

sprintf(szChar,

}

}

int MessageBox(
  HWND hWnd, //拥有该消息的窗口句柄
  LPCTSTR lpText, // 显示的文本
  LPCTSTR lpCaption, // 标题
  UINT uType  //消息窗口类型
);

// 设备上下本句柄, DC句柄

HDC hDC; // DC Device Context

hDC  = GetDC(hwnd);

TextOut(hDC, 0, 50, "Hello World.", strlen("Hello World."));

ReleaseDC(hwnd, hDC); // 要释放, 不然会内存泄露.

break;

WM_PAINT

窗口重绘的处理

hdc = BeginPaint(hwnd, &ps);//只能在WM_PAINT使用

TextOut(hdc, 0, 0, "Hello", strlen("Hello"));

EndPaint(hwnd, &ps);//只能在WM_PAINT使用

break;

WM_CLOSE

if(IDYES == MessageBox(hwnd, "Exit ?", "Notice", MB_YESNO)

{

DestroyWindow(hwnd); //销毁窗口

}

break;

WM_DESTROY

PostQuitMessage(0);

break;

default

DefWindowProc(hwnd, uMsg, wParam, lParam);

CALLBACK __stdcall

WINAPI  __stdcall

WINAPIV  __cdecl // VC默认使用此项

#include <Windows.h>

#include <stdio.h>

LRESULT CALLBACK WinSunProc(

   HWND hwnd,

   UINT uMsg,

   WPARAM wParam,

   LPARAM lParam

   );

int WINAPI WinMain(

   HINSTANCE hInstance,

   HINSTANCE hPrevInstance,

   LPSTR lpCmdLine,

   int nCmdShow

   )

{

WNDCLASS wndclass;

wndclass.cbClsExtra = 0;

wndclass.cbWndExtra = 0;

wndclass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);

wndclass.hCursor = LoadCursor(NULL, IDC_CROSS);

wndclass.hIcon = LoadIcon(NULL, IDI_ERROR);

wndclass.hInstance = hInstance;

wndclass.lpfnWndProc = WinSunProc;

wndclass.lpszClassName = "Xiaodong";

wndclass.lpszMenuName = NULL;

wndclass.style = CS_HREDRAW | CS_VREDRAW;

RegisterClass(&wndclass);

HWND hwnd;

hwnd = CreateWindow("Xiaodong", "DongDongWindow", WS_OVERLAPPEDWINDOW, 0, 0, 600, 400, NULL, NULL, hInstance, NULL);

ShowWindow(hwnd, SW_SHOWNORMAL);

UpdateWindow(hwnd);

MSG msg;

while (GetMessage(&msg, NULL, 0, 0))

{

TranslateMessage(&msg);

DispatchMessage(&msg);

}

return 0;

}

LRESULT CALLBACK WinSunProc(

HWND hwnd,

UINT uMsg,

WPARAM wParam,

LPARAM lParam

)

{

switch(uMsg)

{

case WM_CHAR:

char szChar[20];

sprintf(szChar, "char is %d", wParam);

MessageBox(hwnd, szChar, "Xiaodong...", 0);

break;

case WM_LBUTTONDOWN:

MessageBox(hwnd, "mouse clicked...", "XiaoDong...", 0);

HDC hdc;

hdc = GetDC(hwnd);

TextOut(hdc, 0, 50, "你好啊...", strlen("你好啊..."));

ReleaseDC(hwnd, hdc);

break;

case WM_PAINT:

HDC hDC;

PAINTSTRUCT ps;

hDC = BeginPaint(hwnd, &ps);

TextOut(hDC, 0, 0, "练习窗口...", strlen("练习窗口..."));

EndPaint(hwnd, &ps);

break;

case WM_CLOSE:

if (IDYES == MessageBox(hwnd, "Exit Yes OR No ?", "Notice", MB_YESNO))

{

DestroyWindow(hwnd);

}

break;

case WM_DESTROY:

PostQuitMessage(0);

break;

default:

return DefWindowProc(hwnd, uMsg, wParam, lParam);

}

return 0;

}

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