/// <summary>
/// Reads an object from the source object's extension dictionary.
/// </summary>
/// <typeparam name="T">The type of the object to read.</typeparam>
/// <param name="source">The source object to read the object from.</param>
/// <param name="key">A string that acts as the key in the extension dictionary.</param>
/// <exception cref="System.Exception">Thrown when an AutoCAD error occurs.</exception>
/// <returns>The object in the extension dictionary.</returns>
private static T GetFromXExtensionDictionary <T>(DBObject source, string key)
{
if (source.ExtensionDictionary.IsNull)
{
throw new KeyNotFoundException();
}
try
{
var items = new TypedValue[0];
Helpers.WrapInTransaction(source, tr =>
{
var dict = (DBDictionary)tr.GetObject(source.ExtensionDictionary, OpenMode.ForRead);
if (dict.Contains(key))
{
var xRecord = (Xrecord)tr.GetObject(dict.GetAt(key), OpenMode.ForRead);
items = xRecord.Data
.Cast <TypedValue>()
.ToArray();
}
else
{
throw Error.KeyNotFound(key);
}
});
if (items.Length == 1 &&
(items[0].TypeCode != (int)DxfCode.BinaryChunk ||
typeof(T).Equals(typeof(byte[]))))
{
return((T)items[0].Value);
}
else
{
return(Helpers.Deserialize <T>(items.SelectMany(i => (byte[])i.Value)
.ToArray()));
}
}
catch (Exception e)
{
throw Error.AutoCadException(e);
}
}