RenderDecoratedBox 需要合成大小：缺失

如何解决RenderDecoratedBox 需要合成大小：缺失

相关的导致错误的小部件是：

Container file:///home/bhavesh/AndroidStudioProjects/AudioShow/lib/pages/welcome/phone.dart:124:12
When the exception was thrown,this was the stack: 
#2      RenderBox.size (package:Flutter/src/rendering/Box.dart:1940:12)
#3      RenderDecoratedBox.paint (package:Flutter/src/rendering/proxy_Box.dart:2136:12)
#4      RenderObject._paintWithContext (package:Flutter/src/rendering/object.dart:2322:7)
#5      PaintingContext.paintChild (package:Flutter/src/rendering/object.dart:189:13)
#6      RenderProxyBoxMixin.paint (package:Flutter/src/rendering/proxy_Box.dart:142:15)



...
The following RenderObject was being processed when the exception was fired: RenderDecoratedBox#2711f relayoutBoundary=up5
...  needs compositing
...  parentData: <none> (can use size)
...  constraints: BoxConstraints(w=100.0,0.0<=h<=Infinity)
...  size: MISSING
...  decoration: Boxdecoration
...    color: Color(0xffffffff)
...    borderRadius: BorderRadius.circular(8.0)
...  configuration: ImageConfiguration(bundle: PlatformAssetBundle#d7160(),devicePixelRatio: 3.0,locale: en_US,textDirection: TextDirection.ltr,platform: android)
RenderObject: RenderDecoratedBox#2711f relayoutBoundary=up5
  needs compositing
  parentData: <none> (can use size)
  constraints: BoxConstraints(w=100.0,0.0<=h<=Infinity)
  size: MISSING
  decoration: Boxdecoration
    color: Color(0xffffffff)
    borderRadius: BorderRadius.circular(8.0)
  configuration: ImageConfiguration(bundle: PlatformAssetBundle#d7160(),platform: android)
...  child: RenderFlex#2fab8 relayoutBoundary=up6 NEEDS-PAINT
...    needs compositing
...    parentData: <none> (can use size)
...    constraints: BoxConstraints(w=100.0,0.0<=h<=Infinity)
...    size: MISSING
...    direction: horizontal
...    mainAxisAlignment: start
...    mainAxisSize: max
...    crossAxisAlignment: center
...    textDirection: ltr
...    verticalDirection: down
...    child 1: RenderSemanticsAnnotations#b73cb relayoutBoundary=up7 NEEDS-PAINT
...      needs compositing
...      parentData: offset=Offset(0.0,0.0); flex=null; fit=null (can use size)
...      constraints: BoxConstraints(unconstrained)
...      semantic boundary
...      size: MISSING
...      child: _RenderInputPadding#95409 relayoutBoundary=up8 NEEDS-PAINT
...        needs compositing
...        parentData: <none> (can use size)
...        constraints: BoxConstraints(unconstrained)
...        size: MISSING
...        child: RenderConstrainedBox#4930b relayoutBoundary=up9 NEEDS-PAINT
...          needs compositing
...          parentData: offset=Offset(0.0,0.0) (can use size)
...          constraints: BoxConstraints(unconstrained)
...          size: MISSING
...          additionalConstraints: BoxConstraints(64.0<=w<=Infinity,36.0<=h<=Infinity)
...    child 2: RenderMouseRegion#183ec NEEDS-LAYOUT NEEDS-PAINT
...      needs compositing
...      parentData: offset=Offset(0.0,0.0); flex=null; fit=null
...      constraints: MISSING
...      size: MISSING
...      listeners: enter,exit
...      cursor: SystemMouseCursor(text)
...      child: RenderIgnorePointer#e02f9 NEEDS-LAYOUT NEEDS-PAINT
...        needs compositing
...        parentData: <none>
...        constraints: MISSING
...        size: MISSING
...        ignoring: false
...        ignoringSemantics: implicitly false
...        child: RenderSemanticsAnnotations#8806a NEEDS-LAYOUT NEEDS-PAINT
...          needs compositing
...          parentData: <none>
...          constraints: MISSING
...          size: MISSING

这是有问题的代码

小部件 buildForm() { 新用户； 返回容器（ 宽度：330， 装饰：Boxdecoration( 颜色：Colors.white， borderRadius: BorderRadius.circular(8),),孩子：灵活(

        child: Form(
          key: _formKey,child:Row(
          children:<Widget>[
            CountryCodePicker(
              initialSelection: 'IN',showCountryOnly: false,alignLeft: true,padding: const EdgeInsets.all(4),textStyle: TextStyle(fontSize: 20),TextFormField(
            onChanged: (value1) {
              _formKey.currentState.validate();
              verifyPhone(value1);
            },validator: (value) {
              if (value.isEmpty) {
                setState(() {
                  onSignUpButtonClick = null;
                });
              } else {
                setState(() {
                  onSignUpButtonClick = signUp;

                  user.user.phonenumber=value;

                });
              }
              return null;
            },controller: _phoneNumberController,autocorrect: false,autofocus: false,decoration: Inputdecoration(
              hintText: 'Phonenumber',border: InputBorder.none,focusedBorder: InputBorder.none,enabledBorder: InputBorder.none,errorBorder: InputBorder.none,disabledBorder: InputBorder.none,keyboardType: TextInputType.phone,style: TextStyle(
              fontSize: 20,color: Colors.black,fontWeight: FontWeight.w400,]
),)
);

解决方法

错误解释如下：

Container file:///home/bhavesh/AndroidStudioProjects/AudioShow/lib/pages/welcome/phone.dart:124:12 
.....
64.0<=w<=Infinity,36.0<=h<=Infinity
....

错误可能来自您的 Flexible ，它不应该在容器内使用，而是在行或列中使用。尝试为您的小部件设置约束以识别问题，然后从那里开始工作以使它们具有响应性。