Included null safety libs and now code is not running

Question

I have used null safety libs. Now am getting this problem. Please see the screenshot. Even after adding a null check, it's not going.

body: FutureBuilder(
    future: allPerson(),
    builder: (context, snapshot) {
      if (snapshot.hasError) print(snapshot.error);
      return snapshot.hasData
          ? ListView.builder(
              itemCount: snapshot.data.length,
              itemBuilder: (context, index) {
                List list = snapshot.data;
                return Card(
                  child: ListTile(
                    title: Container(
                      width: 100,
                      height: 100,
                      child: Image.network(
                          "http://192.168.1.101/image_upload_php_mysql/uploads/${list[index]['image']}"),
                    ),
                    subtitle: Center(child: Text(list[index]['name'])),
                  ),
                );
              })
          : Center(
              child: CircularProgressIndicator(),
            );
    },
  ),

Thanks.

We're not here to provide all the code ourselves. include your code not only a screenshot. — Ottoman Coder, Sep 16 '21 at 05:44
refer to my answer here for lenght is not defined error : https://stackoverflow.com/questions/69142424/the-argument-type-asyncsnapshotobject-cant-be-assigned-to-the-parameter-ty/69142526#69142526 — Benyamin, Sep 16 '21 at 06:28
Please ```builder: (context, snapshot) {```` hover on the builder you will find which type of response your snapshot query is returning. if possible then try to add show the query — Ottoman Coder, Sep 16 '21 at 06:51

score 1 · Answer 1 · answered Sep 16 '21 at 08:17

You can give a type to your returned value(s) from future function for snapshot data.

FutureBuilder<List<dynamic>>(
        future: allPerson(),
        builder: (context, AsyncSnapshot<List<dynamic>> snapshot) {
          if (snapshot.hasError) print(snapshot.error);
          return snapshot.hasData
              ? ListView.builder(
                  itemCount: snapshot.data!.length,
                  itemBuilder: (context, index) { ...

Yanni TheDeveloper · Answer 2 · 2021-09-16T07:15:26.837

0

In null safety, you can not set a nullable variable(a variable that can be set as null) to non nullable variable(a variable that doesn't accept the value null).
Here itemCount is non nullable variable, however the variable data is nullable, and may not be available to access the variable length.

itemCount: snapshot.data.length

Try altering it to the following code

itemCount: snapshot.data?["length"] ?? 0

edited Sep 16 '21 at 07:15

answered Sep 16 '21 at 05:40

Yanni TheDeveloper

396
3
7

@JituSingh have updated my answer for you, you should try it out – Yanni TheDeveloper Sep 16 '21 at 07:27

score 0 · Answer 3 · answered Sep 16 '21 at 05:40

0

snapshot.data can be null. So you should use snapshot.data?.length ?? 0

So if snapshot.data is null then it will set length as 0.

answered Sep 16 '21 at 05:40

Ketul Rastogi

163
2
9

The getter 'length' isn't defined for the type 'Object'. – JituSingh Sep 16 '21 at 06:07

score 0 · Answer 4 · answered Sep 16 '21 at 05:44

0

just do this itemCount: snapshot.data!.length

and the problem will gone

answered Sep 16 '21 at 05:44

AL.Sharie

1,526
1
9
14

The getter 'length' isn't defined for the type 'Object'. Created variable but no luck. – JituSingh Sep 16 '21 at 06:05

Included null safety libs and now code is not running

4 Answers4