/// <summary>
/// Browse the server using specified criteria.
/// </summary>
/// <param name="parentItemId">Indicates the item identifier from which browsing will begin. If the root branch is to be browsed then a null should be passed.</param>
/// <param name="filter">The filtering context.</param>
/// <param name="propertiesQuery">The properties query.</param>
/// <returns>
/// Array of browsed elements.
/// </returns>
/// <exception cref="System.InvalidOperationException">Browser isn't attached to com object.</exception>
public OpcDaBrowseElement[] GetElements(string parentItemId, OpcDaElementFilter filter = null,
OpcDaPropertiesQuery propertiesQuery = null)
{
if (OpcBrowse == null)
{
throw new InvalidOperationException("Browser isn't attached to com object.");
}
if (parentItemId == null)
{
parentItemId = string.Empty;
}
if (filter == null)
{
filter = new OpcDaElementFilter();
}
bool returnAllProperties;
bool returnPropertyValues;
IList <int> propertyIds;
if (propertiesQuery != null)
{
returnAllProperties = propertiesQuery.AllProperties;
returnPropertyValues = propertiesQuery.ReturnValues;
propertyIds = propertiesQuery.PropertyIds;
}
else
{
returnAllProperties = false;
returnPropertyValues = false;
propertyIds = new int[0];
}
var opcBrowseElements = OpcBrowse.Browse(parentItemId, filter.ElementType, filter.Name,
filter.VendorSpecific,
returnAllProperties, returnPropertyValues, propertyIds);
if (OpcConfiguration.EnableQuirks && opcBrowseElements.Length > 0 && returnAllProperties &&
NoPropertiesReturned(opcBrowseElements))
{
// bad server implementation of Browse. For example some versions of Matrikon simulation server
// all properties was requested but returned nothing.
// Requery properties with GetProperties
var properties = GetProperties(opcBrowseElements.Select(e => e.ItemId).ToArray(), propertiesQuery);
for (var i = 0; i < opcBrowseElements.Length; i++)
{
opcBrowseElements[i].ItemProperties = properties[i];
}
}
return(opcBrowseElements);
}
/// <summary>
/// Gets properties of items by specified item identifiers.
/// </summary>
/// <param name="itemIds">The item identifiers.</param>
/// <param name="propertiesQuery">The properties query.</param>
/// <returns>
/// Array of properties of items.
/// </returns>
public OpcDaItemProperties[] GetProperties(IList <string> itemIds, OpcDaPropertiesQuery propertiesQuery = null)
{
if (propertiesQuery == null)
{
propertiesQuery = new OpcDaPropertiesQuery();
}
var properties = OpcBrowse.GetProperties(itemIds, propertiesQuery.ReturnValues, propertiesQuery.PropertyIds);
if (OpcConfiguration.EnableQuirks && properties.Length > 0 && propertiesQuery.AllProperties &&
NoPropertiesReturned(properties))
{
// TODO: fallback to IOPCItemProperties
}
return(properties);
}
