请帮忙，要赋值给char*，如何改啊？

[maya8maya85]

函数一开始是这样的

char *g_pData = NULL;
g_uFileLength = 0;
bool Dc(LPWSTR infile)
{
	_wfopen_s(&fp_open, infile, L"rb+");
	
	fseek(fp_open, 0, SEEK_END);
	long lSize = ftell(fp_open); //获取文件大小

	rewind(fp_open);//回到文件头
	
	char * buffer = (char*)malloc(sizeof(char*)*lSize); //分配内存存储整个文件
	
	size_t result = fread(buffer, sizeof(char*), lSize, fp_open); // 将文件拷贝到buffer中

	g_uFileLength = lSize - 888;

	g_pData = new char[(unsigned int)g_uFileLength];
	memcpy(g_pData, buffer, (size_t)g_uFileLength);

	fclose(fp_open);
	delete[] buffer;
    retrun true;
}

现在由于一些原因要改成以下的读取方法，分开一段一段地

bool Dc(LPWSTR infile)
{
	HANDLE HinFile = CreateFile(infile, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
	ULONGLONG flen = SetFilePointer(HinFile, 0, NULL, FILE_END);//文件字节数
	g_pData = new char[(unsigned int)flen -888];
	memset(g_pData, 0, sizeof(g_pData));
	SetFilePointer(HinFile, 0, NULL, FILE_BEGIN);//重置到文件头

	if (HinFile != INVALID_HANDLE_VALUE)
	{
		LARGE_INTEGER llFileSize;
		if (GetFileSizeEx(HinFile, &llFileSize))
		{
			size_t ulBytesToRead = 5 * 1024 * 1024;
			HANDLE hHeap = GetProcessHeap();
			LARGE_INTEGER llReadPos = { 0 };
			while (llReadPos.QuadPart < llFileSize.QuadPart)
			{
				BOOL bResult;
				DWORD dwBytesRead = 0;
				DWORD dwBytesWritten = 0;

				LONGLONG llBytesRest = llFileSize.QuadPart - llReadPos.QuadPart;
				if (llBytesRest < (LONGLONG)ulBytesToRead)
				{
					ulBytesToRead = (size_t)llBytesRest;
				}
				char *lpBytes = (char *)HeapAlloc(hHeap, HEAP_ZERO_MEMORY, ulBytesToRead);
				if (lpBytes == NULL)
				{
					break;
				}

				bResult = ReadFile(HinFile, lpBytes, ulBytesToRead, &dwBytesRead, NULL);
				if (!bResult || (dwBytesRead < ulBytesToRead))
				{
					HeapFree(hHeap, 0, lpBytes);
					break;
				}
		//==》关键在这里
                //strcat_s(g_pData, g_uFileLength, lpBytes); //拼接后最终的g_pData数据不正常
				//bResult = WriteFile(HoutFile, lpBytes, dwBytesRead, &dwBytesWritten, NULL); //尝试写入文件，数据正常
				
				//if (!bResult || (dwBytesWritten < dwBytesRead))
				//{
				//	HeapFree(hHeap, 0, lpBytes);
				//	break;
				//}
				llReadPos.QuadPart += dwBytesRead;
				HeapFree(hHeap, 0, lpBytes);
			}
		}
	}
	CloseHandle(HinFile);
	return true;
}

如何才能用下面这个方法，像上面一样把文件数据给g_pData

[maya8maya85]

没有人会吗？

[ddszhan]

//==》关键在这里，这句注释下面加上： memcpy(g_pData + llReadPos.QuadPart, lpBytes, dwBytesRead);

[maya8maya85]

引用 2 楼 ddszhan 的回复:

//==》关键在这里，这句注释下面加上： memcpy(g_pData + llReadPos.QuadPart, lpBytes, dwBytesRead);

为什么是这个呢？不是要一块一块拼接上去吗？

[zgl7903]

size_t result = fread(buffer, sizeof(char*), lSize, fp_open); sizeof(char*) 指针的大小 32位环境下=4 64位下=8 g_uFileLength = lSize - 888; (unsigned int)g_uFileLength //如果Size小于888 会是什么结果？

[maya8maya85]

引用 4 楼 zgl7903 的回复:

size_t result = fread(buffer, sizeof(char*), lSize, fp_open); sizeof(char*) 指针的大小 32位环境下=4 64位下=8 g_uFileLength = lSize - 888; (unsigned int)g_uFileLength //如果Size小于888 会是什么结果？

我在64位系统调试32位程序，直接设置为8也是不行，一样分配内存失败。不用担心Size大小，项目中在相关判断