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In C# Convert List<dynamic> to List<string>

Suppose I have a List<dynamic> object containing strings:
var dlist = new List<dynamic>()
{
"test",
"test2",
"test3"
};
Is there any efficient way of converting this into a proper List<string> object? I know I can iterate over this list and cast each element to a string, then add this to the result list, but maybe some Linq magic could do the trick in one line?
I tried using some Select() combined with ToList() and Cast<string>, but to no avail. How should this be done properly?
Note: By saying "efficient" I mean of course number of lines of code. I do not take execution time or performance into account. Also - let's suppose I do not need to type check, there will always be strings only in this dynamic list.
EDIT: Okay, so in regards to comments on "why Cast wasn't working for you" - looks like I had another problem regarding the data I receive (I'm using Dapper) and that's why it didn't work. Sorry for the confusion, I thought my list converting was wrong while the problem was not related to this.

Given
var dList = new List<dynamic>() { /*...initialize list */ };
If you are interested in extracting all the strings in the collection, ignoring all other types, you can use:
// Solution 1: Include only strings, no null values, no exceptions thrown
var strings = dlist.OfType<string>().ToList();
If you are certain that all the items in the list are strings (it will throw an exception if they are not), you can use:
// Solution 2: Include strings with null values, Exception for other data types thrown
var strings = dlist.Cast<string>().ToList();
If you want the default string representation, with null for null values, of all the items in the list, you can use:
// Solution 3: Include all, regardless of data type, no exceptions thrown
var strings = dlist.Select(item => item?.ToString()).ToList();

This answer is for dart/flutter
Given
List<dynamic> dList;
You can use
var sList = List<String>.from(dlist);
to convert a List<dynamic> to List<String>

Adding JSON objects to a LIST Unity 3d and C#

I'm trying to add the contents of a JSON file to a LIST. Normally, I would use a loop to iterate through the objects, but using COUNT will not compile and when I use LENGTH, it counts the number of characters in the string.
Do I need to make it a JSONArray when the object is made, and if so, how do I do that? Or do I need another kind of loop? I'm using version 5.2.3f, the last XP compatible version.
Thanks!

You can use MiniJson:
var jsonString = File.ReadAllText(jsonFileName);
var list = Json.Deserialize(jsonString) as List<object>;

c# - cast array list in a string to an array list

I have a string variable like so, which I am receiving from a third party API:
string strArray = "[[1,\"56353657\",\"300\",\"test\",\"<img src=\\\"../Images/Edit.gif\\\" id=\\\"Edit\\\" />\",\"<img src=\\\"../Images/Delete.gif\\\" id=\\\"Delete\\\" />\"],[2,\"56353657\",\"400\",\"test\",\"<img src=\\\"../Images/Edit.gif\\\" id=\\\"Edit\\\" />\",\"<img src=\\\"../Images/Delete.gif\\\" id=\\\"Delete\\\" />\"]]";
I would like to be able to loop through this and retrieve the first 3 items in each of the arrays.
Could someone please advise me as to how to achieve this using c#?

Because values in your array of arrays are not of the same type you can try this way:
String[][] table = JsonConvert.DeserializeObject<String[][]>(strArray);
Then you can loop through this and, if you need, convert values to the desired type.

How do I deserialize a JSON array that contains only values?

I'm getting this result from a web function.
["767,20150221122715,121053103,14573465,1,7,302",
"767,20150221122756,121053165,14573375,1,0,302",
"767,20150221122840,121053498,14572841,1,12,124"]
Usually Json have PropertyName: Value
But this have an array of strings, and each string have the values separated by comma. I know what each value position mean.
I try using JsonConvert.DeserializeObject but couldn't make it work.
string deserializedProduct = JsonConvert.DeserializeObject<string>(json);
//and
List<string> deserializedProduct = JsonConvert.DeserializeObject<string>(json);
I can parse the string doing a split, but I'm wondering if there is an easy way.

To answer your question, according to to http://json.org/, it is a valid JSON value (an array of string).
To deserialize it according to this stack overflow question you should use
JsonConvert.DeserializeObject<List<string>>(json);
to convert it

The generic parameter to the DeserializeObject<T>() method is the type you want the deserializer to deserialize to. Your json string represents an array of strings so you should be deserializing to a collection of strings (typically List<string>).
var values = JsonConvert.DeserializeObject<List<string>>(json);
However, it isn't necessary to specify the type. There is a non-generic overload that returns object. It will (in this case) return an instance of a JArray with the appropriate values.
object values = JsonConvert.Deserialize(json);
Though, it would be better to return a more specific type if possible. To keep it more generalized, you can use JToken for the generic type or even more specifically, JArray.
var values = JsonConvert.Deserialize<JToken>(json); // good
var values = JsonConvert.Deserialize<JArray>(json); // better in this case

Deserialise JSON with Json.Net and test content of array

I'm deserialising JSON using JSON.Net along the same lines as the accepted solution to this question: Deserialize json object into dynamic object using Json.net. Essentially:
dynamic d = JObject.Parse("{number:1000, str:'string', array: [1,2,3,4,5,6]}");
Console.WriteLine(d.number);
Console.WriteLine(d.str);
Console.WriteLine(d.array.Count);
Difference being my array has strings rather than numbers. The above methods work fine. However, what I want to do is test if the array contains a particular value. If it was a typed array of strings I could use myArray.IndexOf("ValueToFind") and if it returns a value > -1 then it's in there. However, this isn't working and I think it's because it's actually an array of JValues rather than strings.
I can iterate through the array, cast each one to a string and then test (i.e. a foreach loop with an if statement inside) but I was hoping for a more succinct single line test. Can anyone advise if there is a simpler way to do the test?
Thanks

JSON.NET can seamlessly convert JArray to List<string>, so you can use
Console.WriteLine(d.array.ToObject<List<string>>().IndexOf("1"));
This works even with JSON integer array.

I got a slightly messier answer by first converting your dynamic array to a known type:
IEnumerable<JToken> d2 = d.array;
Then you can use Any as an extension method.
if (d2.Any(p => p.ToString() == "1")) //etc.