c# - Can't convert a Marshal pointer of a struct back to struct -

i'm coding windows service communicates driver, such i'm trying to, test, pass struct , returned struct.

in c++ working in c# i'm not being able convert intptr struct using marshal , that's why i'm not able struct returned driver.

struct:

[structlayout(layoutkind.sequential)] struct testest {     public int value; } 

then in driver:

typedef struct _test_est {     int value; } test_est, *ptest_est; 

and code going pass struct via ioctl is:

void sendioctl<t>(intptr hdevice, uint dwiocontrolcode, ref t inobj, ref t outobj)     {         intptr inpointer = intptr.zero;         intptr outpointer = intptr.zero;         int inobjsize = 0;         int outobjsize = 0;         uint bytesreturned = 0;          if(inobj != null)         {             inobjsize = marshal.sizeof(inobj.gettype());             inpointer = marshal.allochglobal(inobjsize);             marshal.structuretoptr(inobj, inpointer, false);              if (dwiocontrolcode == test_ctl) // test ioctl             {                 testest lets = new testest();                  logger.log("isnull: " + (inpointer == intptr.zero));                 logger.log("sizeobj: " + inobjsize);                  marshal.ptrtostructure(inpointer, lets);                 logger.log("working!: " + lets.value);             }         }     }    public void sendtest()     {         testest request = new testest();         testest result = new testest();          request.value = 30;          sendioctl(hdriver, test_ctl, ref request, ref result);          logger.log("ra: " + result.value + " " + request.value);     } 

logger.log() writes entry windows event viewer.

i omitted actual deviceiocontrol because that's not fails, happening in the

marshal.ptrtostructure(inpointer, lets); 

is causing service show in logs:

and inpointer not null , inobjsize 4

i tried removing t, sendioctl , placing t it's same.

thanks in advance

to marshal pointer structure use approach

var test = (t) marshal.ptrtostructure(inpointer, typeof(t)); 

do not forget use marshal.freehglobal(inpointer) when you're done our allocated memory blocks.