Incorrect use of parentdatawidget when the exception was thrown, this was the stack:

The following assertion was thrown while applying parent data.:
Incorrect use of ParentDataWidget.

The ParentDataWidget Expanded(flex: 1) wants to apply ParentData of type FlexParentData to a RenderObject, which has been set up to accept ParentData of incompatible type StackParentData.

Usually, this means that the Expanded widget has the wrong ancestor RenderObjectWidget. Typically, Expanded widgets are placed directly inside Flex widgets.
The offending Expanded is currently placed inside a Stack widget.

The ownership chain for the RenderObject that received the incompatible parent data was:
  ConstrainedBox ← Container ← Expanded ← Stack ← Column ← Padding ← ColoredBox ← ConstrainedBox ← Container ← Consumer<InvestmentModel> ← ⋯
When the exception was thrown, this was the stack: 
#0 RenderObjectElement._updateParentData.<anonymous closure> (package:flutter/src/widgets/framework.dart:5816:11)
#1 RenderObjectElement._updateParentData (package:flutter/src/widgets/framework.dart:5832:6)
#2 ParentDataElement._applyParentData.applyParentDataToChild (package:flutter/src/widgets/framework.dart:5066:15)
#3 ComponentElement.visitChildren (package:flutter/src/widgets/framework.dart:4729:14)
#4 ParentDataElement._applyParentData.applyParentDataToChild (package:flutter/src/widgets/framework.dart:5069:15)
...
====================================================================================================
flutter: ViewStateModel---constructor--->DocumentaryModel

Error reporting discovery Stack I don't know what is wrong in the layout , Look at the code
It turns out that
Expanded Components , stay “Container、Padding、Stack” Caused in the component .
Expanded、Flexible Only in Row、Column In other components , Not used in other components .
Modify the method to remove Expanded

      return Container(
          width: MediaQuery.of(context).size.width,
          padding: EdgeInsets.fromLTRB(16, 6, 16, 0),
          color: appWhite,
          child:
              Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
            Stack(children: [
              Expanded( // Get rid of this 
                child: Container(
                    width: MediaQuery.of(context).size.width,
                    child: _buildAmountTextField(model)),
              ),
              Positioned(
                  right: 1.0,
                  bottom: 0,
                  child: Container(
                    margin: EdgeInsets.only(bottom: 8),
                    child: Row(
                        crossAxisAlignment: CrossAxisAlignment.center,
                        children: [
                          Container(
                              height: 42,
                              child: CupertinoButtonWidget(
                                  radius: 4,
                                  color: appWhite,
                                  child: Text(
                                      S().string_documentary_investment_max,
                                      style: t14blue),
                                  onPressed: () {
    
                                    model.setMax(context);
                                  })),
                          SizedBox(
                            width: 4,
                          ),
                          Container(
                            width: 1,
                            height: 42,
                            color: colorD8D8D8,
                          ),
                          SizedBox(
                            width: 12,
                          ),
                          Text(data?.investmentCoinSymbol ?? "",
                              style: t16blackNormal),
                        ]),
                  ))
            ]),