private void InitDefaultValueFromTypeInfo(
ConfigurationPropertyAttribute configurationProperty,
DefaultValueAttribute defaultValueAttribute)
{
object defaultValue = configurationProperty.DefaultValue;
// If the ConfigurationPropertyAttribute has no default try the DefaultValueAttribute
if (ConfigurationElement.IsNullOrNullProperty(defaultValue))
{
defaultValue = defaultValueAttribute?.Value;
}
// Convert the default value from string if necessary
if (defaultValue is string && (Type != typeof(string)))
{
try
{
defaultValue = Converter.ConvertFromInvariantString((string)defaultValue);
}
catch (Exception ex)
{
throw new ConfigurationErrorsException(SR.Format(SR.Default_value_conversion_error_from_string,
Name, ex.Message));
}
}
// If we still have no default, use string Empty for string or the default for value types
if (ConfigurationElement.IsNullOrNullProperty(defaultValue))
{
if (Type == typeof(string))
{
defaultValue = string.Empty;
}
else if (Type.IsValueType)
{
defaultValue = TypeUtil.CreateInstance(Type);
}
}
SetDefaultValue(defaultValue);
}
private void SetDefaultValue(object value)
{
// Validate the default value if any. This should make errors from invalid defaults easier to catch
if (ConfigurationElement.IsNullOrNullProperty(value))
{
return;
}
if (!Type.IsInstanceOfType(value))
{
if (!Converter.CanConvertFrom(value.GetType()))
{
throw new ConfigurationErrorsException(SR.Format(SR.Default_value_wrong_type, Name));
}
value = Converter.ConvertFrom(value);
}
Validate(value);
DefaultValue = value;
}