dynamic and anonymous
In my previous post, I mentioned the idea of creating a
record out of a class. I did work on that and wondered if I could
get the with keyword implemented. I knew it worked with records and structs,
but I didn’t know it also worked with anonymous types. I worked on a project
one time that created a lot of anonymous types, and I never really thought about them
being readonly. It makes sense that with would work with them.
That project also used a lot of dynamic types. Anonymous types can be passed
as dynamic parameters to functions. If you have never used the dynamic type,
break out an editor, create a new ExpandoObject and start adding properties to it
(add a Func or Action for more fun).
It’s fun to play with, but I don’t recommend using it in production code.
One thing that I approve of is using dynamic/ExpandoObject for is ad-hoc
JSON serialization. If you need to create non-trivial JSON object quickly,
this is a great approach.
dynamic expando = new ExpandoObject();
expando.Property1 = "Value1";
expando.Property2 = "Value2";
expando.List = new List<string> { "One", "Two" };
expando.Dictionary = new Dictionary<string, int>()
{
{ "Key1", 1 },
{ "Key2", 2 }
};
var options = new JsonSerializerOptions { WriteIndented = true };
string jsonString = JsonSerializer.Serialize(expando, options);
Console.WriteLine(jsonString);
/*
{
"Property1": "Value1",
"Property2": "Value2",
"List": [
"One",
"Two"
],
"Dictionary": {
"Key1": 1,
"Key2": 2
}
}
*/
Granted, for this example it is a bit overkill, but if you need to create a more complex object without a good JSON editor, this is a great way to do it. Of course, create proper classes if you are going to be doing this a lot, but for quick and easy JSON, this works. Combine this with Visual Studio’s “Paste JSON as Classes” feature and you can quickly prototype a class and then use that in your code.
This has been your semi-regular diversion into “stupid C# tricks”.