public static bool Convert(object val, Type targetType, out object result)
{
result = val;
// Trivial cases
if (val == null)
{
// Cannot convert null to value type
return(!targetType.IsValueType);
}
if (targetType.IsAssignableFrom(val.GetType()))
{
return(true);
}
// Custom type conversions
if (_customTypeConverter != null)
{
if (_customTypeConverter(val, targetType, out result))
{
return(true);
}
}
// TODO: typeof(Nullable<T>)
// Built-in type conversions
if (val.GetType() == typeof(string) && targetType == typeof(Type))
{ // string -> Type
result = Type.GetType(val.ToString());
return(result != null);
}
// Enumerations
if (val.GetType() == typeof(string) && targetType.IsEnum)
{ // string -> Enum
result = Enum.Parse(targetType, (string)val);
return(true);
}
// String target type must be done before enumerations are tried - else, the string will be treated as enumeration
if (targetType.IsAssignableFrom(typeof(string)))
{ // * -> string
result = val.ToString();
return(true);
}
// Collection types
Type enumerableType;
Type entryType;
ReflectionHelper.FindImplementedEnumerableType(targetType, out enumerableType, out entryType);
if (enumerableType != null) // Targets IList, ICollection, IList<>, ICollection<>
{
ICollection col;
if (!ToCollection(val, entryType, out col))
{
return(false);
}
List <object> resultList = col.Cast <object>().ToList();
result = resultList;
return(true);
}
ICollection sourceCol = val as ICollection;
if (sourceCol != null && sourceCol.Count == 1) // From collection to non-collection target
{
// Use the first (single) item of a collection or dictionary
IEnumerator enumerator = sourceCol.GetEnumerator();
enumerator.MoveNext();
object item = enumerator.Current;
if (Convert(item, targetType, out result)) // Single collection item
{
return(true);
}
KeyValuePair <object, object>?kvp = item as KeyValuePair <object, object>?;
if (kvp.HasValue && Convert(kvp.Value.Value, targetType, out result)) // Value of single dictionary entry - generic dictionary
{
IDisposable d = kvp.Value.Key as IDisposable;
if (d != null)
{
d.Dispose();
}
return(true);
}
DictionaryEntry?entry = item as DictionaryEntry?;
if (entry.HasValue && Convert(entry.Value.Value, targetType, out result)) // Value of single dictionary entry - legacy dictionary
{
IDisposable d = entry.Value.Key as IDisposable;
if (d != null)
{
d.Dispose();
}
return(true);
}
}
// Simple type conversions
System.ComponentModel.TypeConverter tc = TypeDescriptor.GetConverter(targetType);
if (tc != null && tc.CanConvertFrom(val.GetType()))
{
try
{
result = tc.ConvertFrom(null, CultureInfo.InvariantCulture, val);
return(true);
}
catch { }
}
tc = TypeDescriptor.GetConverter(val);
if (tc != null && tc.CanConvertTo(targetType))
{
result = tc.ConvertTo(val, targetType);
return(true);
}
return(false);
}
