Serialize and deserialize a collection to JSON Delphi - json

Question

I've searched a lot, but cannot find a working solution. Most likely because I'm pretty new to Delphi (and coming from C#).
I have a unit with the following class declaration:
TReplaceField = class
public
Key: string;
Value: string;
constructor Create; overload;
constructor Create(strKey, strValue: string); overload;
end;
Class can also be record, like suggested in the comment.
I want to create a collection of it, be it an array, TList<T>, or whatever suits best in this case, and then serialize it to JSON (to store it) and later deserialze it to loop over the fields.
I've found REST.JSON and TJson.ObjectToJsonString(), which works good for 1 object.
But if I pass an array of TReplaceField, it gives me a compile error:
E2010 Incompatible types: 'TObject' and 'Dynamic array'
When I use a TList at runtime, I get a different error:
type tkPointer is not currently supported
In C#, all of this is pretty easy, like a few lines of code. I'm pretty stuck on how to do it in Delphi (besides creating JSON by hand via string concatenation).
UPDATE:
With the tips from David, I've got the serialization working. Also deserialization of one object works, but not deserialization of a collection.
My class now looks like this:
TReplaceField = class
private
FKey : string;
FValue : string;
published
property Key : string read FKey write FKey;
property Value : string read FValue write FValue;
public
constructor Create; overload;
constructor Create(strKey, strValue: string); overload;
end;
Serialize one object: mmoJson.Lines.Text := TJson.ObjectToJsonString(Field); OK
Deserialize one object: JsonToObject<TReplaceField>(mmoJson.Lines.Text); OK
Serialize collection: mmoJson.Lines.Text := TJson.ObjectToJsonString(FieldList); OK
Deserialize collection: JsonToObject<TReplaceField>(mmoJson.Lines.Text); FAIL, message:
EConversionError with message 'Internal: Cannot instantiate type System.Generics.Collections.TList<uReplaceField.TReplaceFieldRec>'
Using a record instead of class for ReplaceField gives the same results.
Almost there. What am I missing to get it fully working?

Answer 1

type
TReplaceCollect = TList<TReplaceField>;
Add this after-class declaration.