Flutter setstate on local variable not updating UI

Question

So I tried to dynamically update an individual listview item. I am using a function to generate each item and I created a local variable in that function. I used setstate to update that variable but the UI is not updating. If i make the same variable global it works but i changes every listview items which I dont want. Does anyone have any tips on doing that? I am new to flutter and Sorry if this has been asked multiple times. I tried searching but couldnt find any solutions. This is a similar code for the item builder function.

Widget generateListItem(){ 
    bool flag= false;
    return InkWell(
       onTap:(){
          setState((){
             flag=true;
          })
       },
       child: Text(flag? "Changed" : "Not Changed"),
    );
}

Solution

the flag is resetted every time you call setState, beacuse the flag is in your generateListItem() widget,

I think you must set the bool in a list, so when you called setState, the state in the list of bool not resetted,

List<bool> flag = [];  // 

Widget generateListItem(int i){ 
flag.add(false);
return InkWell(
   onTap:(){
      setState((){
         flag[i]=true;
      })
   },
   child: Text(flag[i]? "Changed" : "Not Changed"),
);}

Comments

[KuKu]

When rebuild 'generateListItem' by setState(), flag is also reset. So always flag is false.

[Bikram gurung]

Ohh.. That makes more sense now. Is there any way to update the item individually?

[sameer kashyap]

Make it a variable inside the State class instead of inside the method. @Bikramgurung

[Bikram gurung]

If I do that setstate changes every Item. I want to individually change the specific item.

[KuKu]

You need to control that value at top parent widget re-builded. "Page(here)[Stateful widget] - build() - 'generateListItem' widget..."

[KuKu]

Please show me your page source.

[Bikram gurung]

Umm.. sorry for the trouble.. I figured it out after your explanation @KuKu. I created an object for child item and changed its variable. Thank you so much.

[Jerry]

amazing! Map<String,bool> could be too.