What is the correct syntax to PUT serialize angular KeyValue to ASP.NET KeyValuePair?

Question

I was trying to serialize a KeyValue "Array" to send it via PUT over http to my asp.net webserver.

The function in Angular looks like this:

SortAboutUs(data : KeyValue<number,number>[]) {
    this.dataTransmitter.Put(this.apiUrl+'/api/aboutus/sort', data);    
}

and if I debug the following data container then it looks like this:

I have the following in my .net core Webserver's Controller

[HttpPut("[action]")]
public ActionResult<bool> Sort(IList<KeyValuePair<int, int>> dto)
{
    return Ok(_aboutUsService.Sort(dto));
}

However i get the following error when trying to send it via PUT:

The JSON value could not be converted to System.Collections.Generic.List`1[System.Collections.Generic.KeyValuePair`2[System.Int32,System.Int32]]. Path: $[0] | LineNumber: 0 | BytePositionInLine: 8.

Weird thing is that I've already used the same technique in another older version of .net core and there everything seems to work.

I also noticed that since .net core 3.1 the KeyValue in C# changed to KeyValuePair but in older versions of .net core it was KeyValue.

Does that have to do something with my related error?

And how can I serialize the KeyValue from Angular so that my Webserver can read it?

score 0 · Answer 1 · answered Jun 18 '20 at 15:25

0

Your object should go like :-

[
 {
   4: 0
 },
 {
   5: 1
 },
 {
   6: 2
 }
]

answered Jun 18 '20 at 15:25

Aakash Garg

10,649
2
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25

I changed the object like you suggested but I still get the same error. What is the Type declaration of this object in the controller methods param? – Fy Z1K Jun 18 '20 at 15:43
hey apologies your older format works fine, but should you use Dictionary instead of keyvaluepair in .net? – Aakash Garg Jun 18 '20 at 15:52
Thank you for your reply. I tried using IDictionary before but I got the Error that "Dictionary is not suppoorted", for whatsoever reason. Weird thing is that this same technique with IList> worked in an older version (v2.2) of .netcore but it seems to refuse to work since .net core 3.1. – Fy Z1K Jun 18 '20 at 15:58
write a custom converter like given here :- https://stackoverflow.com/questions/21021655/json-serialize-listkeyvaluepairstring-object/21022139 – Aakash Garg Jun 18 '20 at 15:59

score 0 · Accepted Answer · answered Jun 18 '20 at 16:13

I was able to solve the Issue by creating my own KeyValue Class like so:

public class KeyValue<K,V>
{
    public K Key { get; set; }
    public V Value { get; set; }
}

after this my Controller Method now looks like this:

[HttpPut("[action]")]
public ActionResult<bool> Sort([FromBody] IList<KeyValue<int, int>> dto)
{
    return Ok(_aboutUsService.Sort(dto));
}

Thanks to this approach the Controller was able to receive the sent Array of KeyValue over PUT from Angular to my Webserver...

What is the correct syntax to PUT serialize angular KeyValue to ASP.NET KeyValuePair?

2 Answers2