/// <summary>
/// 从特性中获取转换器
/// </summary>
/// <param name="converterAttribute">特性</param>
/// <param name="typeToConvert">待转换类型</param>
/// <param name="classTypeAttributeIsOn">所属类型</param>
/// <param name="memberInfo">成员信息</param>
/// <returns></returns>
private BinaryConverter GetConverterFromAttribute(BinaryConverterAttribute converterAttribute, Type typeToConvert, Type classTypeAttributeIsOn, MemberInfo memberInfo)
{
BinaryConverter converter;
// 如果转换器特性的ConverterType为空，则尝试使用特性的CreateConverter方法来创建
Type type = converterAttribute.ConverterType;
if (type == null)
{
// Allow the attribute to create the converter.
converter = converterAttribute.CreateConverter(typeToConvert);
if (converter == null)
{
ThrowHelper.ThrowInvalidOperationException_SerializationConverterOnAttributeNotCompatible(classTypeAttributeIsOn, memberInfo, typeToConvert);
}
}
else
{
ConstructorInfo ctor = type.GetConstructor(Type.EmptyTypes);
// ConvertType必须是BinaryConverter的子类，并且具有无参数公共构造
if (!typeof(BinaryConverter).IsAssignableFrom(type) || ctor == null || !ctor.IsPublic)
{
ThrowHelper.ThrowInvalidOperationException_SerializationConverterOnAttributeInvalid(classTypeAttributeIsOn, memberInfo);
}
converter = (BinaryConverter)Activator.CreateInstance(type) !;
}
Debug.Assert(converter != null);
if (!converter.CanConvert(typeToConvert))
{
Type underlyingType = Nullable.GetUnderlyingType(typeToConvert);
if (underlyingType != null && converter.CanConvert(underlyingType))
{
if (converter is BinaryConverterFactory converterFactory)
{
converter = converterFactory.GetConverterInternal(underlyingType, this);
}
// Allow nullable handling to forward to the underlying type's converter.
return(NullableConverterFactory.CreateValueConverter(underlyingType, converter));
}
ThrowHelper.ThrowInvalidOperationException_SerializationConverterOnAttributeNotCompatible(classTypeAttributeIsOn, memberInfo, typeToConvert);
}
return(converter);
}
private static JsonConverter GetConverterFromAttribute(JsonConverterAttribute converterAttribute, Type typeToConvert, MemberInfo?memberInfo, JsonSerializerOptions options)
{
JsonConverter?converter;
Type declaringType = memberInfo?.DeclaringType ?? typeToConvert;
Type?converterType = converterAttribute.ConverterType;
if (converterType == null)
{
// Allow the attribute to create the converter.
converter = converterAttribute.CreateConverter(typeToConvert);
if (converter == null)
{
ThrowHelper.ThrowInvalidOperationException_SerializationConverterOnAttributeNotCompatible(declaringType, memberInfo, typeToConvert);
}
}
else
{
ConstructorInfo?ctor = converterType.GetConstructor(Type.EmptyTypes);
if (!typeof(JsonConverter).IsAssignableFrom(converterType) || ctor == null || !ctor.IsPublic)
{
ThrowHelper.ThrowInvalidOperationException_SerializationConverterOnAttributeInvalid(declaringType, memberInfo);
}
converter = (JsonConverter)Activator.CreateInstance(converterType) !;
}
Debug.Assert(converter != null);
if (!converter.CanConvert(typeToConvert))
{
Type?underlyingType = Nullable.GetUnderlyingType(typeToConvert);
if (underlyingType != null && converter.CanConvert(underlyingType))
{
if (converter is JsonConverterFactory converterFactory)
{
converter = converterFactory.GetConverterInternal(underlyingType, options);
}
// Allow nullable handling to forward to the underlying type's converter.
return(NullableConverterFactory.CreateValueConverter(underlyingType, converter));
}
ThrowHelper.ThrowInvalidOperationException_SerializationConverterOnAttributeNotCompatible(declaringType, memberInfo, typeToConvert);
}
return(converter);
}
private JsonConverter GetConverterFromAttribute(JsonConverterAttribute converterAttribute, Type typeToConvert, Type classTypeAttributeIsOn, PropertyInfo?propertyInfo)
{
JsonConverter?converter;
Type?type = converterAttribute.ConverterType;
if (type == null)
{
// Allow the attribute to create the converter.
converter = converterAttribute.CreateConverter(typeToConvert);
if (converter == null)
{
ThrowHelper.ThrowInvalidOperationException_SerializationConverterOnAttributeNotCompatible(classTypeAttributeIsOn, propertyInfo, typeToConvert);
}
}
else
{
ConstructorInfo?ctor = type.GetConstructor(Type.EmptyTypes);
if (!typeof(JsonConverter).IsAssignableFrom(type) || ctor == null || !ctor.IsPublic)
{
ThrowHelper.ThrowInvalidOperationException_SerializationConverterOnAttributeInvalid(classTypeAttributeIsOn, propertyInfo);
}
converter = (JsonConverter)Activator.CreateInstance(type) !;
}
Debug.Assert(converter != null);
if (!converter.CanConvert(typeToConvert))
{
Type?underlyingType = Nullable.GetUnderlyingType(typeToConvert);
if (underlyingType != null && converter.CanConvert(underlyingType))
{
// Allow nullable handling to forward to the underlying type's converter.
return(NullableConverterFactory.CreateValueConverter(underlyingType, converter));
}
ThrowHelper.ThrowInvalidOperationException_SerializationConverterOnAttributeNotCompatible(classTypeAttributeIsOn, propertyInfo, typeToConvert);
}
return(converter);
}