C++ ReadFile函数0x1A读取结束的问题

[烟袅许伊]

cout << mDiskPath << endl;
	HANDLE h = CreateFile(mDiskPath, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, NULL, NULL);
	if (h == INVALID_HANDLE_VALUE)
		return NULL;
	SetFilePointer(h, lBeginPosHigh, &lBeginPosLow , FILE_BEGIN);
	if (mBuffer != NULL)
		delete[] mBuffer;
	mBuffer = new char[dwBufferSize]();
	showBuffer();

	cout<<ReadFile(h, mBuffer, dwBufferSize,&aByteRead, NULL)<<endl;
	cout << GetLastError() << endl;
	showBuffer();
	CloseHandle(h);
	return mBuffer;

[烟袅许伊]

问题是总会在文件中有0x1A的时候停止读取，后面的内容全是0xCDCDCDCD，这是一个启动扇区读取程序，求大牛解答。。。是有什么参数要设置么？找文档没找到。。。结果如此