Deserialize JSON with fpjsonrtti

[bsod]

I am a beginner with lamw and i need to deserialize JSON to a Objecj using fpjsonrtti.

But when i use the code below the android app close.

Code: Pascal  [Select][+][-]

1.    
2.     LReader := TJSONDeStreamer.Create( nil );
3.     try
4.       LReader.Options := [jdoCaseInsensitive];
5.       LReader.JSONToObject( strJSON {String with JSON data}, FList {Object with TCollection} );
6.     finally
7.       LReader.Free;
8.     end;
9.  

Any suggestions?

[dseligo]

Did you create FList somewhere (and free it afterwords)?
Something like:

Code: Pascal  [Select][+][-]

1. type TYourObject = class(TPersistent) // or something like that
2. ...
3. ...
4.     LReader := TJSONDeStreamer.Create( nil );
5. FList := TYourObject.Create;
6.     try
7.       LReader.Options := [jdoCaseInsensitive];
8.       LReader.JSONToObject( strJSON {String with JSON data}, FList {Object with TCollection} );
9.     finally
10.       LReader.Free;
11.     end;
12. ...
13. FList.Free;

[bsod]

Hi dseligo,

It seems to me that we cannot create a variable in the private session of TAndroidModule.

If i use a local variable i can deserialize the object.

But I need the FList variable to be accessed in more areas of the code.

[dseligo]

By 'TAndroidModule' you mean descendant of the class jForm?
Like this below?

Code: Pascal  [Select][+][-]

1. type
2.  
3.   { TAndroidModule1 }
4.  
5.   TAndroidModule1 = class(jForm)

You can have variable in private section (I have it there and it's working).
Maybe you didn't create your form, and you try to use variables in it.

P.S.: I now see that you wrote private session. Did you mean 'section', or session? If later, what do you mean by private session?

[bsod]

For example

Code: Pascal  [Select][+][-]

1.  
2.   TAndroidModule2 = class(jForm)
3.     btnBuscar: jButton;
4.     procedure btnBuscarClick(Sender: TObject);
5.   private
6.     {private declarations}
7.     FList:TClientes;
8.   public
9.     {public declarations}
10.   end;
11.  
12. procedure TAndroidModule2.AndroidModule2Create(Sender: TObject);
13. begin
14.   FList := TClientes.Create;
15. end;
16.  
17. procedure TAndroidModule2.AndroidModule2Destroy(Sender: TObject);
18. begin
19.  
20.   FList.Free;
21.  
22. end;
23.  
24. procedure TAndroidModule2.btnBuscarClick(Sender: TObject);
25. begin
26.  
27.     if not Assigned(FList) then
28.       FList.Create;
29.  
30.     LReader := TJSONDeStreamer.Create( nil );
31.     try
32.       LReader.Options := [jdoCaseInsensitive];
33.       LReader.JSONToObject( strJSON {String with JSON data}, FList {FList dont Assigned} );
34.     finally
35.       LReader.Free;
36.     end;
37.  
38. end;
39.  
40.  

[dseligo]

I think that OnCreate event doesn't work in LAMW. Put this code in 'OnActivityCreate' event:

Code: Pascal  [Select][+][-]

1. procedure TAndroidModule2.AndroidModule2Create(Sender: TObject);
2. begin
3.   FList := TClientes.Create;
4. end;

This is wrong (you need to assign to FList, with :=):

Code: Pascal  [Select][+][-]

1.     if not Assigned(FList) then
2.       FList.Create;

It should be like this:

Code: Pascal  [Select][+][-]

1.     if not Assigned(FList) then
2.       FList := TClientes.Create;