要让一个子填充它的父，只需将它包装到FittedBox中

    FittedBox(
     child: Image.asset('foo.png'),
     fit: BoxFit.fill,
   )

在列中使用这行代码。 对于wrap_content: mainAxisSize: mainaxisize .min 对于match_parent: mainAxisSize: mainaxisize .max

要让一个子填充它的父，只需将它包装到FittedBox中

    FittedBox(
     child: Image.asset('foo.png'),
     fit: BoxFit.fill,
   )

一个简单的解决方法:

如果容器只有一个顶级子容器，则可以为该子容器指定对齐属性并为其赋值。它会填满容器里的所有空间。

Container(color:Colors.white,height:200.0,width:200.0,
 child:Container(
    color: Colors.yellow,
    alignment:Alignment.[any_available_option] // make the yellow child match the parent size
   )
)

另一种方法:

Container(color:Colors.white,height:200.0,width:200.0,
 child:Container(
    color: Colors.yellow,
    constraints:  BoxConstraints.expand(height: 100.0), // height will be 100 dip and width will be match parent
   )
)

使用小部件Wrap。

对于类似列的行为尝试:

  return Wrap(
          direction: Axis.vertical,
          spacing: 10,
          children: <Widget>[...],);

对于Row类行为尝试:

  return Wrap(
          direction: Axis.horizontal,
          spacing: 10,
          children: <Widget>[...],);

有关更多信息:Wrap (Flutter小部件)

MATCH_PARENT

FractionallySizedBox(
            widthFactor: 1.0, // width w.r.t to parent
            heightFactor: 1.0, // height w.r.t to parent

            child: ElevatedButton(
              onPressed: () {},
              child: Text("+"),
            ),
          )

OR

Container(
            height: double.infinity,
            width: double.infinity,
          child: ElevatedButton(
            onPressed: () {},
            child: Text("+"),
          ),
        )

OR

Container(
            height: MediaQuery.of(context).size.height,
            width: MediaQuery.of(context).size.width,
          child: ElevatedButton(
            onPressed: () {},
            child: Text("+"),
          ),
        )

OR

Container(
          constraints: BoxConstraints.expand(),
          child: ElevatedButton(
            onPressed: () {},
            child: Text("+"),
          ),
        )

WRAP_CONTENT

Wrap(children: [
          Container(
            child: ElevatedButton(
              onPressed: () {},
              child: Text("+"),
            ),
          ),
        ])

OR

Container(
          constraints: BoxConstraints.tightFor(),
          child: ElevatedButton(
            onPressed: () {},
            child: Text("+"),
          ),
        )

Match_parent Wrap_content:

Row(
            children: [
          Expanded(
            child: Container(
              child: ElevatedButton(
                onPressed: () {},
                child: Text("+"),
              ),
            ),
          ),
        ])

Wrap_content Match_parent:

Column(
            children: [
          Expanded(
            child: Container(
              child: ElevatedButton(
                onPressed: () {},
                child: Text("+"),
              ),
            ),
          ),
        ])