用脚手架小部件包装表单，然后用SingleChildScrollView包装TextFormField:

 return Container(
          height: screenHeight * .66,
          child: Scaffold(
             body: Form(
               key: _form,
               child: SingleChildScrollView(
                 child:TextFormField()
               )
              )
             )
           )

包:https://pub.dev/packages/modal_bottom_sheet

将小部件包装到Padding中，并像这样设置Padding ==>

padding: MediaQuery.of(context).viewInsets // viewInsets will decorate your screen

你可以使用 showMaterialModalBottomSheet或showModalBottomSheet或showCupertinoModalBottomSheet

showModalBottomSheet(
        context: context,
        barrierColor: popupBackground,
        isScrollControlled: true, // only work on showModalBottomSheet function
        shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.only(
                topLeft: Radius.circular(borderRadiusMedium),
                topRight: Radius.circular(borderRadiusMedium))),
        builder: (context) =>  Padding(
            padding: MediaQuery.of(context).viewInsets,
            child: Container(
                   height: 400, //height or you can use Get.width-100 to set height
                   child: <Your Widget here>
             ),)),)

添加:

isScrollControlled: true表示showModalBottomSheet 填充:MediaQuery.of(上下文)。viewInsets为生成器中的小部件 列/换行都可以

showModalBottomSheet<void>(
  isScrollControlled: true,
  context: context,
  shape: RoundedRectangleBorder(
    borderRadius: BorderRadius.only(
        topLeft: Radius.circular(30.0),
        topRight: Radius.circular(30.0)),
  ),
  builder: (BuildContext context) {
    return Padding(
        padding: MediaQuery.of(context).viewInsets,
        child: Container(
            child: Wrap(
          children: <Widget>[
            TextField(
              decoration: InputDecoration(
                  border: InputBorder.none,
                  hintText: 'Enter a search term'),
            ),
            TextField(
              decoration: InputDecoration(
                  border: InputBorder.none,
                  hintText: 'Enter a search term'),
            ),
            TextField(
              decoration: InputDecoration(
                  border: InputBorder.none,
                  hintText: 'Enter a search term'),
            ),
            TextField(
              decoration: InputDecoration(
                  border: InputBorder.none,
                  hintText: 'Enter a search term'),
            )
          ],
        )));
  },
);

更新2020年2月25日更好的解决方案

showModalBottomSheet(
 isScrollControlled: true,
 builder: (BuildContext context) {

    return SingleChildScrollView(
      child: Container(
        padding:
            EdgeInsets.only(bottom: MediaQuery.of(context).viewInsets.bottom),
        child: Padding(
          padding: const EdgeInsets.fromLTRB(20.0, 20.0, 20.0, 0.0), // content padding
          child: Form(...)) // From with TextField inside


});

我通过增加打开键盘时子部件的高度来解决这个问题。 MediaQuery.of(context). viewinsets的初始值。底部为0，当键盘聚焦时它会改变。

showModalBottomSheet<void>(
      enableDrag: true,
      isScrollControlled: true,
      context: context,
      builder: (BuildContext context) {
        return Card(
          color: Colors.white,
          child: Container(
            height: MediaQuery.of(context).size.height / 2 +
                MediaQuery.of(context).viewInsets.bottom,
            child: Column(
              children: <Widget>[
                TextField(),
                TextField(),
              ],
            ),
          ),
        );
      },
    );

如果你还没有找到你的问题。我认为你们在BuilderContext中漏掉了。有时候当你实现modalBottomSheet时，它只会给你context参数。用BuildContext添加context。

 builder: (BuildContext context) {  //-Here is your issue add BuilderContext class name as it as 
          return Padding(
            padding: MediaQuery.of(context).viewInsets,
            child: SingleChildScrollView(
              child: Padding(
                padding: EdgeInsets.only(bottom: MediaQuery.of(context).viewInsets.bottom),
                child: new Container(

不要在构建器中使用builder:(BuildContext context){}，而是使用builder: (context) {}

有了这个解决方案，我的模态底部表坚持状态栏(行为像脚手架与resizeToAvoidBottomInset: false)，并允许查看所有的表单字段和滚动的形式，如果它仍然需要查看底部文本字段。

要了解更多细节，这里是我找到解决方案的链接- https://github.com/flutter/flutter/issues/18564#issuecomment-602604778