IntPtr in c#

hans

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

8 Replies

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Nate20y ago
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.
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Brandon Turner20y ago
try adding the keyword "ref" before the array name when you are calling the function.
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Nate20y ago
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?
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Brandon Turner20y ago
Ahhh, we have much different goals.
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hans20y ago
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.
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Brandon Turner20y ago
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?
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hans20y ago
thx, this was the solution. yas stefan
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Mike Gold20y ago
Try using one of the Marshal class static methods

string theString = Marshal.PtrToStringAnsi(ResponseBuffer);

best,

Mike G.
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