Flutter Row在构建时消失了吗？

Question

我正在构建一个Chat app flutter页面，我的Textfield / Send Button Row一直在消失，我收到以下错误......

  

'package：flutter / src / rendering / box.dart'：断言失败：第1446行   pos 12：'hasSize'：RenderBox没有布局：   RenderPointerListener＃da9fd NEEDS-LAYOUT NEEDS-PAINT

     

0 _AssertionError._doThrowNew（dart：core-patch / dart：core / errors_patch.dart:37）

     

1 _AssertionError._throwNew（dart：core-patch / dart：core / errors_patch.dart:33）

     

2 RenderBox.size（包：flutter / src / rendering / box.dart:1446:12）

     

3 RenderProxyBoxWithHitTestBehavior.hitTest（包：flutter / src / rendering / proxy_box.dart:164：9）

     

4 RenderBox＆amp; ContainerRenderObjectMixin＆amp; RenderBoxContainerDefaultsMixin.defaultHitTestChildren

     

（包：扑/ SRC /再现/ box.dart：2190：17）

     

5 RenderCustomMultiChildLayoutBox.hitTestChildren（包：flutter / src / rendering / custom_layout.dart：365：12）

     

6 RenderBox.hitTest（包：flutter / src / rendering / box.dart:1863:11）

     

7 RenderBox＆amp; RenderObjectWithChildMixin＆amp; RenderProxyBoxMixin.hitTestChildren

     

（包：扑/ SRC /再现/ P＆LT; ...＆GT;

页面构建正常并在没有textfield / send行的情况下正确显示我的信息，但在添加时出错。这是我的有状态小部件的脚手架中包含的代码......

body: new Container(
          margin: new EdgeInsets.all(10.0),
          child: new Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              new Flexible(
                  child: new FirebaseAnimatedList(
                      query: fb.child('users').limitToLast(50),
                      padding: new EdgeInsets.all(5.0),
                      reverse: true,
                      itemBuilder: (_, DataSnapshot snapshot, Animation<double> animation, int index){

                        return new ChatMessage(
                            snapshot: snapshot,
                            animation: animation
                        );

                      })
              ),
              new Divider(height: 16.0, color: Colors.blue,),
              new Padding(padding: new EdgeInsets.all(10.0)),
              new Row(
                mainAxisAlignment: MainAxisAlignment.center,
                mainAxisSize: MainAxisSize.max,
                children: <Widget>[
                  new IconButton(icon: new Icon(Icons.gif), onPressed: null),
                  new Padding(padding: new EdgeInsets.all(3.0)),
                  new TextField(
                      decoration:
                      new InputDecoration(labelText: "CHAT HERE!!"),
                      controller: _searchController,
                      onSubmitted: (str) {
                        setState(() {
                          str = _searchController.text;
                        });
                      }),
                  new IconButton(icon: new Icon(Icons.send), onPressed: null)
                ],
              )

            ],
          ))

Answer 1

答案是将TextField包装在Flexible中。现在似乎很明显，但有时需要灵活或扩展，有时不需要。这是我的代码......

child: new Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              new Flexible(
                child: new FirebaseAnimatedList(
                    query: fb.child('users').limitToLast(50),
                    padding: new EdgeInsets.all(5.0),
                    reverse: true,
                    itemBuilder: (_, DataSnapshot snapshot,
                        Animation<double> animation, int index) {
                      return new ChatMessage(
                          snapshot: snapshot, animation: animation);
                    }),
              ),
              new Divider(
                height: 5.0,
                color: Colors.blue,
              ),
              new Container(
                margin: const EdgeInsets.symmetric(horizontal: 2.0),
                child: new Row(
                  children: <Widget>[
                    new IconButton(
                        icon: new Icon(Icons.gif), onPressed: getGif),
                    new Flexible(
                      child: new TextField(
                        controller: _chatController,
                        autocorrect: false,
                        decoration: new InputDecoration(
                            labelText: "Let's Talk ... ",
                            labelStyle:
                                new TextStyle(fontWeight: FontWeight.bold)),
                        onChanged: (str) {
                          setState(() {
                            str = _chatController.text;
                          });
                        },
                      ),
                    ),
                    new IconButton(
                        icon: new Icon(Icons.send), onPressed: getGif),
                  ],
                ),
              )
            ],
          )