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Description
Description
When binding configuration, it's normally possible to override the conversion by adding a TypeConverterAttribute attribute to the field, property, or class declaration. It does work when binding against a string value but not against a IConfigurationSection.
Reproduction Steps
https://dotnetfiddle.net/gxB9o3
using Microsoft.Extensions.Configuration;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Globalization;
var configuration = new ConfigurationBuilder()
.AddInMemoryCollection(new Dictionary<string, string>()
{
{ "0", "Hello"},
{ "1", "world"},
})
.Build();
try
{
var options = configuration.Get<Item>();
Console.WriteLine("Binding success.");
}
catch (Exception e)
{
Console.WriteLine("Binding failure.");
}
[TypeConverter(typeof(ItemConverter))]
class Item
{
private string Zero;
private string One;
public Item(string zero, string one)
{
Zero = zero;
One = one;
}
}
class ItemConverter : TypeConverter
{
public override bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceType)
{
return sourceType == typeof(IConfigurationSection);
}
public override object ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object value)
{
var section = (IConfigurationSection)value;
return new Item(section.GetValue<string>("0"), section.GetValue<string>("1"));
}
}Expected behavior
Item is correctly bound
Actual behavior
Failing this message: "Cannot create instance of type 'Item' because one or more parameters cannot be bound to. Constructor parameters must have corresponding properties. Fields are not supported. Missing properties are: 'zero,one'"
Regression?
Not that I know of
Known Workarounds
None that I know of
Configuration
- Runtime: .NET 8.0.5
- OS: Windows 11 Version 23H2
- Architecture: x64
It's probably not specific to that configuration, AFAIK, it's the same behavior in .NET 9 preview versions
Other information
No response