(颤振)如何调用另一个类的setState方法？

Question

我想从另一个类调用方法，我使用了这种方法，但是方法没有正确地调用。`

        class PostModel extends StatefulWidget {
          final profilename;
          final bool isVideoUrl;
          final int urlsource;
          final videoUrl;
          const PostModel(
              {this.profilename,
              required this.isVideoUrl,
              required this.urlsource,
              this.videoUrl});
        
          @override
          State<PostModel> createState() => _PostModelState();
        }
        
        class _PostModelState extends State<PostModel> {
          @override
          Widget build(BuildContext context) {
            return Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                NameSection(),
                InkWell(
                  onDoubleTap: , // **toggleLike()** Want to call from here 
                  child: (widget.isVideoUrl)
                      ? SizedBox(
                          width: MediaQuery.of(context).size.width,
                          height: MediaQuery.of(context).size.width,
                          child: VideoController(videosUrl[widget.urlsource % 6]))
                      : Image(
                          image: NetworkImage(
                              "https://picsum.photos/seed/${widget.urlsource}/400/400"),
                          width: MediaQuery.of(context).size.width,
                          fit: BoxFit.cover,
                        ),
                ),
                PostIcons(), // here is the widget .
                Padding(
                    padding: EdgeInsets.symmetric(horizontal: 10),
                    child:
                        Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
                      SizedBox(
                        height: 5,
                      ),
                      Text(
                        "11,536 likes",
                        style: GoogleFonts.roboto(
                            color: Colors.white,
                            fontSize: 12,
                            fontWeight: FontWeight.bold),
                      ),
                      SizedBox(
                        height: 5,
                      ),
                      Text(
                        "akashbanerjee ‍♀️",
                        style: GoogleFonts.roboto(
                            color: Colors.white,
                            fontSize: 12,
                            fontWeight: FontWeight.bold),
                      ),
                      SizedBox(
                        height: 5,
                      ),
                      Text(
                        "View all 244 comments ",
                        style: GoogleFonts.roboto(
                            color: Color.fromARGB(255, 186, 186, 186), fontSize: 12),
                      ),
                      SizedBox(
                        height: 5,
                      ),
                      Text(
                        "5 hours ago",
                        style: GoogleFonts.roboto(
                            color: Color.fromARGB(255, 186, 186, 186), fontSize: 10),
                      ),
                      SizedBox(
                        height: 10,
                      ),
                      Divider(
                        color: Color.fromARGB(255, 77, 77, 77),
                        indent: 0,
                        endIndent: 0,
                      )
                    ]))
              ],
            );
          }
        }
    
    ```
    ```
    
        class PostIcons extends StatefulWidget {
          const PostIcons({Key? key}) : super(key: key);
        
          @override
          State<PostIcons> createState() => PostIconsState();
        }
    
        class PostIconsState extends State<PostIcons> {
          bool liked = false;
        
          toggleLike() { // i want to call this function from above class.
            setState(() {
              liked = !liked;
            });
          }
        
          bool saved = false;
          toggleSavePost() {
            setState(() {
              saved = !saved;
              ScaffoldMessenger.of(context).showSnackBar(SnackBar(
                content: (saved) ? Text("Post saved") : Text("Post unsaved"),
                duration: Duration(milliseconds: 1000),
              ));
            });
          }
        
          showShareBottomModal() {
            // setState(() {
            showModalBottomSheet<void>(
                // context and builder are
                // required properties in this widget
                backgroundColor: Color.fromARGB(255, 38, 38, 38),
                shape: const RoundedRectangleBorder(
                  borderRadius: BorderRadius.only(
                      topLeft: Radius.circular(24), topRight: Radius.circular(24)),
                ),
                context: context,
                builder: (BuildContext context) {
                  // we set up a container inside which
                  // we create center column and display text
                  // Returning SizedBox instead of a Container
                  return SharePost();
                });
            // });
          }
        
          @override
          Widget build(BuildContext context) {
            return Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Row(
                  children: [
                    IconButton(
                        onPressed: toggleLike,
                        iconSize: 28,
                        icon: Icon(
                          liked ? Icons.favorite : Icons.favorite_outline,
                          color: liked ? Colors.red : Colors.white,
                        )),
                    // SizedBox(
                    //   width: 0,
                    // ),
                    Transform(
                      alignment: Alignment.center,
                      transform: Matrix4.rotationY(math.pi),
                      child: IconButton(
                          iconSize: 28,
                          onPressed: null,
                          icon: Icon(
                            FeatherIcons.messageCircle,
                            color: Colors.white,
                          )),
                    ),
                    IconButton(
                        onPressed: showShareBottomModal,
                        iconSize: 28,
                        icon: Icon(
                          FeatherIcons.send,
                          color: Colors.white,
                        )),
                  ],
                ),
                IconButton(
                  onPressed: toggleSavePost,
                  iconSize: 28,
                  icon: Icon(saved ? Icons.bookmark : Icons.bookmark_border_outlined),
                  color: Colors.white,
                )
              ],
            );
          }
        }

PostModel类

class Feeds extends StatefulWidget {
 

  @override
  State<Feeds> createState() => _FeedsState();
}

class _FeedsState extends State<Feeds> {
  @override
  Widget build(BuildContext context) {
    return Column(
      children: List.generate(storyList.length, (index) {
        return PostModel(isVideoUrl: false, urlsource: index);
      }),
    );
  }
}

Postmodel小部件在另一个类的列表中。

因此，有人能建议我一些很好的实用方法来调用其他类的setState (不是孩子，也不是家长，完全不同的类)。

Answer 1

当您使用这样的GlobalKey时，还需要将该键提供给您试图用它控制的小部件。所以在你的情况下

PostIcons(key: globalKey)

下面是一个小部件使用这样的键控制另一个小部件的最小工作示例：

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());
final GlobalKey<AState> globalKey = GlobalKey();

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        home: Scaffold(
            body: Center(
                child: Column(children: [
      A(key: globalKey),
      TextButton(
          onPressed: () {
            globalKey.currentState?.increaseI();
          },
          child: Text("click"))
    ]))));
  }
}

class A extends StatefulWidget {
  const A({Key? key}) : super(key: key);

  @override
  State<A> createState() => AState();
}

class AState extends State<A> {
  int i = 1;

  void increaseI() {
    setState(() {
      i++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Text(i.toString());
  }
}

编辑：

因此，对于您的代码，尝试添加

final GlobalKey<PostIconsState> globalKey = GlobalKey();

在你的_PostModelState里面。所以就在下面

    class _PostModelState extends State<PostModel> {

然后这一行：

            PostIcons(), // here is the widget .

你换到

            PostIcons(key: globalKey), // here is the widget .

然后你就可以改变

              onDoubleTap: , // **toggleLike()** Want to call from here 

至

              onDoubleTap: () => globalKey.currentState?.toggleLike(),

我认为您之前遇到的问题是globalKey是在类之外定义的。通过在类中定义它，可以确保每个实例都有不同的键。