23、Windows API 进程间通信，数据复制消息(WM_COPYDATA)
WM_COPYDATA是一个非常特殊的消息，此消息可能携带一个比较大的消息参数，而其他消息都只能携带两个固定大小的参数(WPARAM和LPARAM)。
在发送WM_COPYDATA消息时，WM_COPYDATA的wParam参数应该赋值为发送此消息的窗口，而lParam消息参数指向一个COPYDATASTRUCT结构类型的变量。
typedef struct tagCOPYDATASTRUCT {
ULONG_PTR dwData;
DWORD cbData;
PVOID lpData;
} COPYDATASTRUCT, *PCOPYDATASTRUCT;
dwData可以是任意值，lpData是需要发送给目录窗口所在进程的数据，cbData字符指定了lpData内存区域的字节数，也就是需要发送给目标进程的lpData所指向的数据的大小。
在消息发送时，系统会将整个COPYDATASTRUCT及lpData所指向的内容全部发送给目标进程。目标进程窗口在收到WM_COPYDATA后，可以从lParam参数中提取出数据。
1、一个例子
数据发送端
通过WM_COPYDATA进程间通信-发送端
通过WM_COPYDATA进程间通信
**************************************/
/*
头文件
*/
#include
<
windows.h
>
#include
<
commctrl.h
>
#include
"
resource.h
"
/*
全局变量
*/
HINSTANCE hinst;
HWND hwnd, hwndEdit;
LPSTR lpszCopy
=
"
you can input any text\n then click \'Send\' Item at Menu
"
;
/*
函数声明
*/
int
WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR,
int
);
LRESULT CALLBACK MainWndProc(HWND, UINT, WPARAM, LPARAM);
/*
************************************
* WinMain
*************************************
*/
int
WINAPI WinMain(
HINSTANCE hinstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int
nCmdShow)
{
MSG msg;
WNDCLASSEX wcx;
hinst
=
hinstance;
//
保存应用程序实例
//
填充WNDCLASSEX
wcx.cbSize
=
sizeof
(wcx);
wcx.style
=
CS_HREDRAW
|
CS_VREDRAW;
wcx.lpfnWndProc
=
MainWndProc;
//
消息处理函数
wcx.cbClsExtra
=
0
;
wcx.cbWndExtra
=
0
;
wcx.hInstance
=
hinstance;
wcx.hIcon
=
LoadIcon(NULL, IDI_APPLICATION);
wcx.hCursor
=
LoadCursor(NULL, IDC_ARROW);
wcx.hbrBackground
=
(HBRUSH)GetStockObject( WHITE_BRUSH);
wcx.lpszMenuName
=
MAKEINTRESOURCE(IDR_MENU_COMMAND);
//
菜单
wcx.lpszClassName
=
"
copydata
"
;
//
窗口类名
wcx.hIconSm
=
NULL;
//
注册窗口类
if
(RegisterClassEx(
&
wcx)
==
0
)
{
return
0
;
}
//
创建窗口
hwnd
=
CreateWindow(
"
copydata
"
,
"
Sample
"
,
WS_TILEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
500
,
400
,
(HWND) NULL,
(HMENU) NULL,
hinstance,
(LPVOID) NULL);
if
(
!
hwnd)
return
0
;
//
显示、刷新窗口
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
//
消息循环
BOOL fGotMessage;
while
((fGotMessage
=
GetMessage(
&
msg, (HWND) NULL,
0
,
0
))
!=
0
&&
fGotMessage
!=
-
1
)
{
TranslateMessage(
&
msg);
DispatchMessage(
&
msg);
}
return
msg.wParam;
UNREFERENCED_PARAMETER(lpCmdLine);
}
/*
************************************
* 消息处理函数
*************************************
*/
LONG APIENTRY MainWndProc(HWND hwnd,
UINT message,
WPARAM wParam,
LPARAM lParam)
{
switch
(message)
{
case
WM_CREATE:
{
//
在主窗口创建时，创建一个EDIT控件，用于编辑需要复制的内容
RECT rectMain;
GetClientRect(hwnd,
&
rectMain);
hwndEdit
=
CreateWindow(
"
EDIT
"
,
NULL,
WS_CHILD
|
WS_VISIBLE
|
WS_VSCROLL
|
WS_BORDER
|
ES_LEFT
|
ES_MULTILINE
|
ES_AUTOVSCROLL,
0
.,
0
, rectMain.right, rectMain.bottom,
hwnd, NULL,
(HINSTANCE) GetWindowLong(hwnd, GWL_HINSTANCE),
NULL);
if
(hwndEdit
==
NULL)
{
MessageBox(hwnd,
"
Create Window Error
"
,
"
ERROR
"
,MB_OK);
ExitProcess(
0
);
}
//
设置EDIT控件的内容
SendMessage(hwndEdit, WM_SETTEXT,
0
, (LPARAM) lpszCopy);
break
;
}
case
WM_COMMAND:
//
菜单输入
{
//
如果通过菜单点击“send”按钮
if
(LOWORD(wParam)
==
ID_COMMAND_SEND)
{
//
获取EDIT控件中的文本
DWORD dwTextLenth
=
GetWindowTextLength(hwndEdit);
LPSTR szText
=
(LPSTR)HeapAlloc(GetProcessHeap(),HEAP_NO_SERIALIZE,dwTextLenth);
GetWindowText(hwndEdit,szText,dwTextLenth);
//
构造 COPYDATASTRUCT
COPYDATASTRUCT cds;
HWND hwnd2
=
FindWindow(
"
copydata2
"
,
"
RECV COPY DATA
"
);
if
(hwnd2
==
NULL)
{
MessageBox(hwnd,
"
can not find window 2
"
,
"
ERROR
"
,MB_OK);
break
;
}
cds.dwData
=
0x12345678
;
//
自定义的数据
cds.cbData
=
dwTextLenth;
//
lpData的长度
cds.lpData
=
szText;
//
需要复制的数据
//
发送消息，COPYDATASTRUCT结构的指针做为lParam
SendMessage(
hwnd2,
//
目的窗口
(UINT) WM_COPYDATA,
//
消息 ID
(WPARAM) hwnd,
//
wParam，源窗口句柄
(LPARAM)
&
cds
//
lParam，COPYDATASTRUCT
);
//
释放内存
HeapFree(GetProcessHeap(),HEAP_NO_SERIALIZE,szText);
}
break
;
}
case
WM_DESTROY:
//
退出
PostQuitMessage(
0
);
return
0
;
default
:
//
其他消息的处理
return
DefWindowProc(hwnd, message, wParam, lParam);
}
return
0
;
}
数据接收端
通过WM_COPYDATA进程间通信－接收端
通过WM_COPYDATA进程间通信
**************************************/
/*
头文件
*/
#include
<
windows.h
>
#include
<
commctrl.h
>
/*
全局变量
*/
HINSTANCE hinst;
HWND hwnd,hwndEdit;
/*
函数声明
*/
int
WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR,
int
);
LRESULT CALLBACK MainWndProc(HWND, UINT, WPARAM, LPARAM);
/*
************************************
* void main()
* 功能 进程间mailslot通信客户端
*************************************
*/
int
WINAPI WinMain(
HINSTANCE hinstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int
nCmdShow)
{
MSG msg;
WNDCLASSEX wcx;
//
填充WNDCLASSEX
wcx.cbSize
=
sizeof
(wcx);
wcx.style
=
CS_HREDRAW
|
CS_VREDRAW;
wcx.lpfnWndProc
=
MainWndProc;
wcx.cbClsExtra
=
0
;
wcx.cbWndExtra
=
0
;
wcx.hInstance
=
hinstance;
wcx.hIcon
=
LoadIcon(NULL, IDI_APPLICATION);
wcx.hCursor
=
LoadCursor(NULL, IDC_ARROW);
wcx.hbrBackground
=
(HBRUSH)GetStockObject( WHITE_BRUSH);
wcx.lpszMenuName
=
NULL;
wcx.lpszClassName
=
"
copydata2
"
;
wcx.hIconSm
=
NULL;
//
注册窗口类
if
(RegisterClassEx(
&
wcx)
==
0
)
{
return
0
;
}
//
创建窗口
hwnd
=
CreateWindow(
"
copydata2
"
,
"
RECV COPY DATA
"
,
WS_TILEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
500
,
400
,
(HWND) NULL, (HMENU) NULL, hinstance, (LPVOID) NULL
);
if
(
!
hwnd)
return
0
;
//
显示刷新窗口
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
//
消息
BOOL fGotMessage;
while
((fGotMessage
=
GetMessage(
&
msg, (HWND) NULL,
0
,
0
))
!=
0
&&
fGotMessage
!=
-
1
)
{
TranslateMessage(
&
msg);
DispatchMessage(
&
msg);
}
return
msg.wParam;
UNREFERENCED_PARAMETER(lpCmdLine);
return
0
;
}
//
消息处理函数
LONG APIENTRY MainWndProc(HWND hwnd,
UINT message,
WPARAM wParam,
LPARAM lParam)
{
switch
(message)
{
case
WM_CREATE:
{
//
创建主窗口时，创建一个EDIT控件
RECT rectMain;
GetClientRect(hwnd,
&
rectMain);
hwndEdit
=
CreateWindow(
"
EDIT
"
,
NULL,
WS_CHILD
|
WS_VISIBLE
|
WS_VSCROLL
|
WS_BORDER
|
ES_LEFT
|
ES_MULTILINE
|
ES_AUTOVSCROLL,
0
.,
0
, rectMain.right, rectMain.bottom,
hwnd,
NULL,
(HINSTANCE) GetWindowLong(hwnd, GWL_HINSTANCE),
NULL);
if
(hwndEdit
==
NULL)
{
MessageBox(hwnd,
"
Create Window Error
"
,
"
ERROR
"
,MB_OK);
ExitProcess(
0
);
}
break
;
case
WM_COPYDATA:
{
//
当收到WM_COPYDATA消息时，从lParam中提取出
//
COPYDATASTRUCT
PCOPYDATASTRUCT lpcds
=
(PCOPYDATASTRUCT)lParam;
//
将复制的数据在界面上显示
SetWindowText(hwndEdit,(LPSTR)lpcds
->
lpData);
break
;
}
case
WM_DESTROY:
//
退出
PostQuitMessage(
0
);
return
0
;
default
:
//
其他消息处理
break
;
}
}
return
DefWindowProc(hwnd, message, wParam, lParam);
}
Interprocess Communications[2]
参考
[1] 精通Windows API 函数、接口、编程实例
[2] http://msdn.microsoft.com/en-us/library/ms648710%28VS.85%29.aspx