Flutter 中 ListView.builder 上的 GestureDetector

Question

I am trying to add a GestureDetector on my ListView widget which contains Images but it does not seem to work. A similar question has been asked about it before but that did not help either.

Here is my code:

ListView.builder(
          scrollDirection: Axis.horizontal,
          itemBuilder: (BuildContext ctx, int index) {
            return Container(
                width: 160,
                child: Card(
                 child: Wrap(
                  children: <Widget>[
                     GestureDetector( onTap: () => Print_on_layout(index),
                      child: Image.network(a[index], fit: BoxFit.fill,)
                     )
                  ],
                ),
              ),
            );
          },
          itemCount: a.length,
        ),

Answer 1

I suppose this has something to do with the wrap Widget, which might be messing with the space where the tap can be detected. Try removing it. If that doesn't work, please tell us if you get an error.

Answer 2

Use gesturedetector as a parent of the container not on image. as in the list you are only returning a single widgit so you should container with gesture detector. Try this code:

ListView.builder(
            scrollDirection: Axis.horizontal,
              itemBuilder: (BuildContext ctx, int index) {
                return
                  GestureDetector(onTap: () => Print_on_layout(index),
    
                  child: Container(
                    width: 160,
                    child: Card(
                      child: Wrap(
                        children: <Widget>[
                          Image.network(a[index], fit: BoxFit.fill,)
                        ],
                      ),
                    ),
                  ),
                );
              },
              itemCount: a.length,
            ),