Null check operator used on a null value FirebaseFirestore-CodePudding

I want to sort the posts in my application by date, but when I use orderby I get a null check operator used on a null value error.

My code below:

StreamBuilder(
                  stream: FirebaseFirestore.instance
                      .collection('posts')
                      .where('uid', isEqualTo: widget.uid)
                      .orderBy(
                        'datePublished',
                        descending: true,
                      )
                      
                      .snapshots(),
                      
                  builder: (context, snapshot) {
                    if (snapshot.connectionState == ConnectionState.waiting) {
                      return const Center(
                        child: CircularProgressIndicator(),
                      );
                    }
                    return ListView.builder(
                        primary: false,
                        shrinkWrap: true,
                        itemCount: (snapshot.data! as dynamic).docs.length,
                        itemBuilder: (context, index) {
                          DocumentSnapshot snap =
                              (snapshot.data! as dynamic).docs[index];

CodePudding user response：

because stream can be return null value then snapshot.data! as dynamic make error. Please check snapshot.hasData

CodePudding user response：

Add 1 more condition

if (snapshot.data == null) {
                      return const Center(
                        child: CircularProgressIndicator(),
                      );
                    }