Dictionary model binding behaves different with Enum as Key vs Value #50748
Description
Is there an existing issue for this?
- I have searched the existing issues
Describe the bug
Consider the following example:
[ApiController]
[Route("[controller]")]
public class TestController : ControllerBase
{
[HttpGet]
[Route("key")]
public IActionResult KeyTest([FromQuery] Dictionary<TestEnum, string> prop)
{
return Ok();
}
[HttpGet]
[Route("value")]
public IActionResult ValueTest([FromQuery] Dictionary<string, TestEnum> prop)
{
return Ok();
}
}
public enum TestEnum
{
EnumVal1,
EnumVal2
}
The following requests produce the 200 response and a populated dictionary:
/Test/key?Prop[enumval1]=string
/Test/value?Prop[string]=enumval1
The following request produces an invalid modelstate with a 400 response:
/Test/value?Prop[string]=badEnum
The following request produces an internal server error:
/Test/key?Prop[badEnum]=string
The stack trace shows the following error:
System.FormatException: badEnum is not a valid value for TestEnum.
---> System.ArgumentException: Requested value 'badEnum' was not found.
at System.Enum.TryParseByName(RuntimeType enumType, ReadOnlySpan`1 value, Boolean ignoreCase, Boolean throwOnFailure, UInt64& result)
at System.Enum.TryParseInt32Enum(RuntimeType enumType, ReadOnlySpan`1 value, Int32 minInclusive, Int32 maxInclusive, Boolean ignoreCase, Boolean throwOnFailure, TypeCode type, Int32& result)
at System.Enum.TryParse(Type enumType, ReadOnlySpan`1 value, Boolean ignoreCase, Boolean throwOnFailure, Object& result)
at System.Enum.Parse(Type enumType, String value, Boolean ignoreCase)
at System.ComponentModel.EnumConverter.ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, Object value)
--- End of inner exception stack trace ---
Is there a reason for the difference in binding behavior? Is it possible to have the Dictionary<TestEnum, string> produce a model state error instead of throwing a FormatException?
Expected Behavior
No response
Steps To Reproduce
No response
Exceptions (if any)
No response
.NET Version
No response
Anything else?
No response