title: All children of this widget must have a key in reorderable
body: <p>I am trying to make a ReorderableListView, which needs a key. I put it, however it returns the error "All children of this widget must have a key". Can anyone help me? (I've seen similar problems here but I still couldn't solve it). I saw some examples that used the key of this form, however the index it does not recognize the index as shown in the image</p>
  
  <pre><code>ReorderableListView(
                onReorder: _onReorder,
                scrollDirection: Axis.vertical,
                padding: const EdgeInsets.symmetric(vertical: 8),
                children: &lt;Widget&gt;[
                  ListView.builder(
                      itemCount: dias.length,
                      itemBuilder: (context, int index) {
                        return Padding(
                          key: ValueKey(dias[index]),
                          padding: EdgeInsets.all(0),
                          child: _cartaodia(context, index),
                        );
                      }
                  ),
            ],
            )
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/g8QW1.png" rel="nofollow noreferrer">enter image description here</a></p>