Possible to pass a list of integer through web api or do I have to use a string param

Question

I have a scenario where I need to send multiple ProductIds in a GET Request to my Web API.

In my asp.net web api controller is there a way that I can make the param of my Action method be of type List<int> productIds. I am assuming no, I have to pass them like this ?ProductIds=1,2,3 and then accept it as string productIds.

Please let me know if there is a better way.

Solution

You can indicate that you are going to be accepting an int[] as your parameter and Web API should handle mapping the comma-delimited string to an array as expected. You may need to include the [FromUri] attribute to let Web API know that you are expecting these values from the querystring :

public IEnumerable<Product> GetProducts([FromUri] int[] ProductIds)
{
      // Your code here.
}

You could also indicate that multiple values are mapped to the same querystring parameter via :

?ProductIds=1&ProductIds=2&ProductIds=3...

Comments

[Blake Rivell]

Ok so what should my query string param look like and what should the param in my Action Method look like? Additionally does it have to be an array? Can I use list?

[Rion Williams]

The comma-delimited string approach that you are using should work just fine or you could use the second approach that I provided (i.e. repeated querystring parameters). Filip Woj has a blog post on this topic that goes into a bit more detail and even uses a custom binder to handle comma-delimited values.

[Blake Rivell]

Do you know why if I don't pass the param at all the list is coming in as instantiated with a count of 0? I expect it to be null.

[Blake Rivell]

I have the param like: List<int> productIds = null

[Mrinal Kamboj]

Will [FromUri] help in transferring a lots of data, like list of 1000 items, will it not be cumbersome sending it

[girlcode]

This does not work for a comma separated list as described.