public static object ConvertType(object value, Type type)
{
ArgumentGuard.NotNull(type, nameof(type));
if (value == null)
{
if (!CanContainNull(type))
{
throw new FormatException($"Failed to convert 'null' to type '{type.Name}'.");
}
return(null);
}
Type runtimeType = value.GetType();
if (type == runtimeType || type.IsAssignableFrom(runtimeType))
{
return(value);
}
string stringValue = value.ToString();
if (string.IsNullOrEmpty(stringValue))
{
return(GetDefaultValue(type));
}
bool isNullableTypeRequested = type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable <>);
Type nonNullableType = Nullable.GetUnderlyingType(type) ?? type;
try
{
if (nonNullableType == typeof(Guid))
{
Guid convertedValue = Guid.Parse(stringValue);
return(isNullableTypeRequested ? (Guid?)convertedValue : convertedValue);
}
if (nonNullableType == typeof(DateTimeOffset))
{
DateTimeOffset convertedValue = DateTimeOffset.Parse(stringValue);
return(isNullableTypeRequested ? (DateTimeOffset?)convertedValue : convertedValue);
}
if (nonNullableType == typeof(TimeSpan))
{
TimeSpan convertedValue = TimeSpan.Parse(stringValue);
return(isNullableTypeRequested ? (TimeSpan?)convertedValue : convertedValue);
}
if (nonNullableType.IsEnum)
{
object convertedValue = Enum.Parse(nonNullableType, stringValue);
// https://bradwilson.typepad.com/blog/2008/07/creating-nullab.html
return(convertedValue);
}
// https://bradwilson.typepad.com/blog/2008/07/creating-nullab.html
return(Convert.ChangeType(stringValue, nonNullableType));
}
catch (Exception exception) when(exception is FormatException || exception is OverflowException ||
exception is InvalidCastException || exception is ArgumentException)
{
throw new FormatException(
$"Failed to convert '{value}' of type '{runtimeType.Name}' to type '{type.Name}'.", exception);
}
}