/// <summary>
/// 获取类型转换器
/// </summary>
/// <param name="typeToConvert"></param>
/// <returns></returns>
public BinaryConverter GetConverter(Type typeToConvert)
{
// 从缓存获取
if (_converters.TryGetValue(typeToConvert, out BinaryConverter converter))
{
Debug.Assert(converter != null);
return(converter);
}
// Priority 2: Attempt to get custom converter added at runtime.
// Currently there is not a way at runtime to overide the [BinaryConverter] when applied to a property.
foreach (BinaryConverter item in Converters)
{
if (item.CanConvert(typeToConvert))
{
converter = item;
break;
}
}
// Priority 3: Attempt to get converter from [BinaryConverter] on the type being converted.
if (converter == null)
{
BinaryConverterAttribute converterAttribute = (BinaryConverterAttribute)
GetAttributeThatCanHaveMultiple(typeToConvert, typeof(BinaryConverterAttribute));
if (converterAttribute != null)
{
converter = GetConverterFromAttribute(converterAttribute, typeToConvert: typeToConvert, classTypeAttributeIsOn: typeToConvert, memberInfo: null);
}
}
// Priority 4: Attempt to get built-in converter.
if (converter == null)
{
if (s_defaultSimpleConverters.TryGetValue(typeToConvert, out BinaryConverter foundConverter))
{
Debug.Assert(foundConverter != null);
converter = foundConverter;
}
else
{
foreach (BinaryConverter item in s_defaultFactoryConverters)
{
if (item.CanConvert(typeToConvert))
{
converter = item;
break;
}
}
// Since the object and IEnumerable converters cover all types, we should have a converter.
Debug.Assert(converter != null);
}
}
// Allow redirection for generic types or the enum converter.
if (converter is BinaryConverterFactory factory)
{
converter = factory.GetConverterInternal(typeToConvert, this);
// A factory cannot return null; GetConverterInternal checked for that.
Debug.Assert(converter != null);
}
Type converterTypeToConvert = converter.TypeToConvert;
if (!converterTypeToConvert.IsAssignableFromInternal(typeToConvert) &&
!typeToConvert.IsAssignableFromInternal(converterTypeToConvert))
{
ThrowHelper.ThrowInvalidOperationException_SerializationConverterNotCompatible(converter.GetType(), typeToConvert);
}
// Only cache the value once (de)serialization has occurred since new converters can be added that may change the result.
if (_haveTypesBeenCreated)
{
// A null converter is allowed here and cached.
// Ignore failure case here in multi-threaded cases since the cached item will be equivalent.
_converters.TryAdd(typeToConvert, converter);
}
return(converter);
}
