Solved

What is parameter 4 in WriteFile()

Posted on 2000-02-22
1
400 Views
Last Modified: 2008-03-06
I face a problem to insert the proper lpNumberOfBytesWritten which is the parameter 4 in WriteFile(). after build, it show error "cannot convert parameter 4 from 'int *' to 'unsigned long *'. i'm sending 1 byte of data to hDevice. WriteFile(hDevice,nPtr,1,1,NULL). what's wrong with the command?
thanks.
0
Comment
Question by:giggs11
1 Comment
 
LVL 22

Accepted Solution

by:
nietod earned 50 total points
ID: 2548677
The problem is that an int is signed, but it wants an unsigned value (actually a pointer to an unsigned value.)  Since the parameter is declared as LPDWORD (i.e a pointer to a DWORD) Try

DWORD BytWrt;

WriteFile(hDevice,nptr,1,&BytWrt,NULL)
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Unlike C#, C++ doesn't have native support for sealing classes (so they cannot be sub-classed). At the cost of a virtual base class pointer it is possible to implement a pseudo sealing mechanism The trick is to virtually inherit from a base class…
IntroductionThis article is the second in a three part article series on the Visual Studio 2008 Debugger.  It provides tips in setting and using breakpoints. If not familiar with this debugger, you can find a basic introduction in the EE article loc…
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.
The viewer will be introduced to the member functions push_back and pop_back of the vector class. The video will teach the difference between the two as well as how to use each one along with its functionality.

863 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

18 Experts available now in Live!

Get 1:1 Help Now