I want to refresh my Text "ganzerchat" but it dont works with how i do it

thats my Chat Class (StatefulWidget) i tryed with setstate but nothing happens everytime.

I opened the Chat from the main.dart

List chatverlauf = [];

Future getDataFromYourApi() async {
  List<String> tmp = [];
  final response = await http.get(Uri.parse(url));
  final extractedData = json.decode(response.body) as Map<String, dynamic>;

  chatverlauf.clear();
  ganzerChat = "";

  extractedData.forEach((id, data) {
    tmp.add(data["name"]   ": "   data["text"]);
    //print(data["name"]   ": "   data["text"]);
    
  });
  return tmp;
}

Future<void> loadChat() async{
  
  chatverlauf = await getDataFromYourApi();
  

  setState(() {
    ganzerChat = chatverlauf.join("\n");
    print(ganzerChat);
  });
}


return Scaffold(
  appBar: AppBar(
    title: Text("Chat"),
  ),
  body: Container(
    alignment: Alignment.center,
    child:
        Column(mainAxisAlignment: MainAxisAlignment.end, children: <Widget>[
      Container(
          margin: EdgeInsets.only(right: 20, bottom: 50),
          alignment: Alignment.centerRight,
          child: Text(
            ganzerChat,
            textAlign: TextAlign.right,
          )),
      Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: <Widget>[
          Container(
              width: 300,
              color: Colors.grey,
              child: TextField(controller: eingabecontroller)),
          ElevatedButton(
            child: Text("Senden"),
            onPressed:()async{
              await loadChat();
            },
          ),
        ],
      ),
    ]),
  ),
);

}

maybe anyone here have the same problem and can help me

CodePudding user response：

I found the problem. It was because I had the methods below the Widget build. I put it above then it worked!

Sorry for the time waste, I thank you very much anyway.

CodePudding user response：

Try to create a new function to set chatverlauf values. Something like this: getDataFromYourApi():

Future<void> loadChat() async{
    ganzerChat = "";
    chatverlauf = await getDateFromYourApi();

    for(int i=0;i<chatverlauf.lenght;i  ){
        ganzerChat = ganzerChat   chatverlauf[i]   "\n";
    }
    setState(() {
       ganzerChat = ganzerChat   "";
    });

}

In your ElevatedButton:

ElevatedButton(
   child: Text("Senden"),
   onPressed: ()async{
      await loadChat();
   }
),

CodePudding user response：

You don't need to use a for cycle to join the array of Strings. Just do a join with the \n as the separator:

setState(() {
  ganzerChat = chatverlauf.join("\n")
});

CodePudding user response：

Now, in the function getDataFromYourApi() try this:

Future <List<String>> getDataFromYourApi() async {
  ...
  
}

CodePudding user response：

Maybe I set my Statefull widget incorrectly.

Stateful widget