CODEWITHSUNDEEP
flutterdart
Ooto
Ooto

Reputation: 1247

Flutter: How to add an extra ListTile to ListView manually

What I want to do is to add an extra LisTile to the last of ListView but I still don't figure it out. My current code is like this.

child: ListView.builder(
        itemBuilder: (context, index) {
          if (index == 0) {
            // Add an extra item to the start
            return ListTile(
             ...
            );
          }
          index -= 1;
          final item = _items[index];

          // I want to an extra item here as well
          if (index == _items.length) {
              return ListTile();
          }

          return ListTile(
              ...
          );


        },
        itemCount: _items.length + 2,

I've already tried the way above, but it doesn't work. There is an error.

Invalid value: not in range 0..4, inclusive 5

When I changed itemCount to _items.length + 1, it doesn't show the extra ListTile I want to add to the end.

Upvotes: 2

Views: 2013

Answers (2)

Mammad
Mammad

Reputation: 119

If you want to add to the beginning and the end as well check below

child: ListView.builder(
        itemBuilder: (context, index) {
          if (index == 0) {
            // Add an extra item to the start
            return ListTile(
             ...
            );
          }
          if (index == _items.length + 1) {
              return ListTile();
          }

          index -= 1;
          final item = _items[index];



          return ListTile(
              ...
          );


        },
        itemCount: _items.length + 2,

Upvotes: 3

Mammad
Mammad

Reputation: 119

your bug is here:

itemCount: _items.length + 2,

you should increase it by one

because you added 2 elements and for the last call you get index = list.length + 1, and then you subtract 1 from it, and you end up 1 over your length.

ex lets say your list have 5 elements, because you have 

itemCount: _items.length + 2

Listview will call your func 7 times, and in 7th call your index is 6 and you are doing index =-1, which equals to 5, and 5 is over your range. (you have form 0 to 4)

Upvotes: 0

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