MapViewOfFile 求解

[DontKissBossAss]

如下代码在第一次执行MapViewOfFile时没有问题，但是再打开一个进程时， 执行失败. 这应该不是CreateFileMapping的权限问题吧。

第二个进程在执行该函数时失败，GetLastError返回得到的结果是5
// ERROR_ACCESS_DENIED 5 (0x5) Access is denied.

在网上查的资料， 但是没找见跟这个类似的。

	HANDLE hMapFile = NULL;
	char   *szData  = NULL;

	hMapFile = OpenFileMapping(PAGE_READWRITE, NULL, "TEST");
	if (hMapFile == NULL)
	{
		printf("The First Program, It Will Create Mapping File\n");

		hMapFile = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, 4*1024, "TEST");
		if (hMapFile == NULL)
		{
			printf("Create Mapping File Failed\n");

			system("PAUSE");
			return 0;
		}
	}
	else
	{
		printf("Program Has been open more than once\n");
	}

	szData = (char*)MapViewOfFile(hMapFile, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0);
	if (szData == NULL)
	{
                  // ERROR_ACCESS_DENIED 5 (0x5)  Access is denied.
		printf("Map View Of FIle Failed, %d\n", GetLastError());
		CloseHandle(hMapFile);
		system("PAUSE");
		return 0;
	}

[至善者善之敌]

操作的是啥文件，明显提示权限不够

[老邓]

建议尝试下第二个参数：

lpAttributes 
[in] Pointer to a SECURITY_ATTRIBUTES structure that determines whether the returned handle can be inherited by child processes. If lpAttributes is NULL, the handle cannot be inherited. 
Windows NT/2000/XP: The lpSecurityDescriptor member of the structure specifies a security descriptor for the new file-mapping object. If lpAttributes is NULL, the file-mapping object gets a default security descriptor. 

[辰岡墨竹]

OpenFileMapping第一个参数传错了，应该为以下之一
FILE_MAP_ALL_ACCESS
FILE_MAP_EXECUTE
FILE_MAP_READ
FILE_MAP_WRITE
PAGE_READWRITE是CreateFileMapping的标志，你可以用FILE_MAP_ALL_ACCESS方式打开。

[辰岡墨竹]

把第一个OpenFileMapping的那个PAGE_READWRITE替换成FILE_MAP_READ | FILE_MAP_WRITE或者FILE_MAP_ALL_ACCESS。
还有szData最好是void *或者BYTE *，直接操作内存最好不要用有符号的char

[野男孩]

权限不够。楼上的都说了，参数不对。