How to use DictionaryModelBinder?

Question

ASP.NET Core 2.2 DictionaryModelBinder

[HttpGet("{id}", Name = "GetValue")]
public async Task<IActionResult> GetValue(
[ModelBinder(BinderType=typeof(DictionaryModelBinder<string,string>))] 
    IDictionary<string, string> id)
{
     return Ok();
}

Error:

InvalidOperationException: Multiple constructors accepting all given argument types have been found in type 'Microsoft.AspNetCore.Mvc.ModelBinding.Binders.DictionaryModelBinder`2[System.String,System.String]'. There should only be one applicable constructor.

Answer 1

After some source code analyze, I found the way to use DictionaryModelBinder.

[HttpGet("GetValue")]
public async Task<IActionResult> GetValue([FromQuery] IDictionary<string, string> id)
{
     return Ok();
}

and the request should be

api/GetValue?id.Key1=Value1&id.Key2=Value2&id.Key3=Value3

(OR)

api/GetValue?id[Key1]=Value1&id[Key2]=Value2&id[Key3]=Value3

Note

• No need to explicitly use ModelBinderAttribute. This is added by default
• We need to add FromQueryAttribute for the parameter