Locating And Using Methods

Method objects (ICommand nodes in GenICam) can be bound in exactly the same way however special care must be taken as their names contain information about the argument list of the method. Tools like ImpactControlCenter present method names not in the way they are used in an applications code, but in a more human readable way, thus reading this section is important when working with method objects in Impact Acquire:

//-----------------------------------------------------------------------------
// This function will try to obtain the handle to a certain driver feature list
HOBJ getDriverList( HDRV hDrv, const char* pName, const char* pAddListName, TDMR_ListType type )
//-----------------------------------------------------------------------------
{
  TPROPHANDLING_ERROR objResult;
  TDMR_ERROR dmrResult;
  HOBJ hObj = INVALID_ID;
  HLIST baseList;
 
  // try to locate the base list for these property
  if( ( dmrResult = DMR_FindList( hDrv, pAddListName, type, 0, &baseList ) ) == DMR_NO_ERROR )
  {
    // try to locate the property
    if( ( objResult = OBJ_GetHandleEx( baseList, pName, &hObj, smIgnoreProperties | smIgnoreMethods, 0 ) ) != PROPHANDLING_NO_ERROR )
    {
      printf( "OBJ_GetHandle for %s failed: %d Handle: %d. This list might not be supported by this device\n", pName, objResult, hObj );
    }
  }
  else
  {
    printf( "DMR_FindList failed: %d. Lists of type %d are not available for this device\n", dmrResult, type );
  }
  return hObj;
}
 
//-----------------------------------------------------------------------------
HOBJ getSettingProp( HDRV hDrv, const char* pSettingName, const char* pPropName )
//-----------------------------------------------------------------------------
{
  return getDriverProperty( hDrv, pPropName, pSettingName, dmltSetting );
}
 
//-----------------------------------------------------------------------------
void myFun()
//-----------------------------------------------------------------------------
{
  HDRV hDrv = getTheDriverHandleFromSomewhere();
  // find the feature and bind it to the method object. Here it is crucial to notice that the exact name
  // of a method object in mvIMPACT_Acquire is constructed from the actual feature name, the return type
  // of the method and the arguments expected by the method (optional). More information about this topic
  // can be found in the documentation under the functions 'OBJ_Execute', 'OBJ_GetSParamList' or 'OBJ_GetSWithInplaceConstruction' with 'sqMethParamString'.
  HOBJ hMeth = getSettingProp( hDrv, "Base", "TriggerSoftware@i" );
  // '@i' indicates, that calling this function will return an integer
  // (the result of the function call, which is either 0 or a negative value in case of an error)
  // and takes no parameters
  int functionResult = 0;
  // now the method is ready to use when available:
  if( hMeth != INVALID_ID )
  {
    OBJ_Execute( hMeth, 0, 0, &functionResult );
  }
  else
  {
    // oops... The feature is not offered by this device
  }
}