IntPtr in c#

Question

Hi im new in c# and id like to work with winmm.dll from windows. so i imported it this way: [DllImport(winmm.dll)] extern static int mciSendString(string command IntPtr responseBuffer int bufferLength int nothing); which works fine for me. But now i want to read a string out of my responseBuffer and i dont know how to de-referncate. In good old c iwould have used the  *  operator so plz tell me what to use/do in c#. thx yas stefan

Nate · Answer

I tried using the ref but I got an error. cannot convert from 'ref string[]' to 'System.IntPtr' I had something like this in my code. string[] myStringArray = { one two three four }; function(ref myStringArray); Is that what you said to do? There has got to be more but I am not sure what it is.

Brandon Turner · Answer

try adding the keyword ref before the array name when you are calling the function.

Nate · Answer

I need to pass an array of strings as an IntPtr to interface with something that uses a DLL. How do I do this? I have tried many different ways using Marshals and other stuff. It does not seem to work. I get memory allocation problems or I have errors in my code. What can I do to fix my problem?

Brandon Turner · Answer

Ahhh we have much different goals.

hans · Answer

im working on a audio recorder. playing audio files works already. my aim is to program an application which records radio sequences that are longer than a given time and have a signal strength stronger than a given limit. something like rec all pro from sagebrush.

Brandon Turner · Answer

Out of curioisty what are you making with winmm? I'm currently in the process of making a media player myself in C# using winmm. Are you working on something simalir?

hans · Answer

thx this was the solution. yas stefan

Mike Gold · Answer

Try using one of the Marshal class static methods string theString = Marshal.PtrToStringAnsi(ResponseBuffer); best Mike G.