GestureDetector (Exception caught by gesture)

Question

I'm trying to make a todo app. I create objects in card view, but when I press the delete icon on them when I first start the application, they do not delete the objects, they act as if I clicked the card and it gives this error. In the later ones, only the short text in red.

Expanded(
              child: ListView.builder(
                itemCount: allTodo.length,
                itemBuilder: (context, index) {
                  return Card(
                    child: ListTile(
                      onTap: () {
                        if (allTodo[index].ID == null) {
                          print("id is null, cant perform add operation");
                          return;
                        }
                        _controllerTitle.text = allTodo[index].title;
                        clickedTodoID = allTodo[index].ID!;
                        setState(() {});
                      },
                      title: Text(allTodo[index].title),
                      trailing: GestureDetector(
                        onTap: () {
                          if (allTodo[index].ID != null) {
                            _deleteTodo(allTodo[index].ID!, index);
                             setState(() {});
                          } else {
                            print("id is null, cant perform Delete operation");
                          }
                        },
                        child: Icon(Icons.delete),
                      ),
                    ),
                  );
                },
              ),
            ),

---

todo.dart

class Todo {
  int? ID;
  late String title;

  Todo(this.title);
  Todo.withId(this.ID, this.title);

  Map<String, dynamic> toMap() {
    var map = Map<String, dynamic>();
    map["ID"] = ID;
    map["title"] = title;
    return map;
  }

  Todo.fromMap(Map<String, dynamic> map) {
    this.ID = map["ID"];
    this.title = map["title"];
  }
}

Answer 1

Most likely allTodo[index].ID is null here.

Try

onTap: () {
  if (allTodo[index].ID == null) {
    return;
  }
  setState(() {
    _controllerTitle.text = allTodo[index].title;
    clickedTodoID = allTodo[index].ID!;
  });
},

Use this snippet

return Card(
  child: ListTile(
    onTap: () {
      if (allTodo[index].ID == null) {
        print("id is null, cant perform add operation");
        return;
      }

      _controllerTitle.text = allTodo[index].title;
      clickedTodoID = allTodo[index].ID!;
      setState(() {});
    },
    title: Text(allTodo[index].title),
    trailing: GestureDetector(
      onTap: () {
        if (allTodo[index].ID != null) {
          _deleteTodo(allTodo[index].ID!, index);
          setState(() {});
        } else {
          print("id is null, cant perform Delete operation");
        }
      },
      child: Icon(Icons.delete),
    ),
  ),
);