垂直视口高度为无界

这是我的代码:

@override
Widget build(BuildContext context) {
  return new Material(
    color: Colors.deepPurpleAccent,
    child: new Column(
     mainAxisAlignment: MainAxisAlignment.center,
        children:<Widget>[new GridView.count(crossAxisCount: _column,children: new List.generate(_row*_column, (index) {
          return new Center(
              child: new CellWidget()
          );
        }),)]
    )
  );
}

例外情况如下:

I/flutter ( 9925): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter ( 9925): The following assertion was thrown during performResize():
I/flutter ( 9925): Vertical viewport was given unbounded height.
I/flutter ( 9925): Viewports expand in the scrolling direction to fill their container.In this case, a vertical
I/flutter ( 9925): viewport was given an unlimited amount of vertical space in which to expand. This situation
I/flutter ( 9925): typically happens when a scrollable widget is nested inside another scrollable widget.
I/flutter ( 9925): If this widget is always nested in a scrollable widget there is no need to use a viewport because
I/flutter ( 9925): there will always be enough vertical space for the children. In this case, consider using a Column
I/flutter ( 9925): instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size
I/flutter ( 9925): the height of the viewport to the sum of the heights of its children.
I/flutter ( 9925): 
I/flutter ( 9925): When the exception was thrown, this was the stack:
I/flutter ( 9925): #0      RenderViewport.performResize.<anonymous closure> (package:flutter/src/rendering/viewport.dart:827:15)
I/flutter ( 9925): #1      RenderViewport.performResize (package:flutter/src/rendering/viewport.dart:880:6)
I/flutter ( 9925): #2      RenderObject.layout (package:flutter/src/rendering/object.dart:1555:9)

当前回答

我们可以用两种方法来解决上述问题

1. 使用灵活的部件，

Flexible小部件可以在Row、Column和Flex中使用。扩展以填充主轴中的可用空间的灵活性(例如，水平扩展[Row]或垂直扩展[Column])

但是，请记住，与Expanded不同，The Flexible小部件不需要子部件填充可用空间。所以，最好使用Flexible。

Column(
  children: <Widget>[
    Flexible( 
      child: ListView(...),
    ),
  ],
)

2. 使用shrinkWrap: true

使用shrinkWrap为true，我们告诉Listview渲染它的List到可用空间，而不是在剩余屏幕以下。

Column(
  children: <Widget>[
    ListView(
      shrinkWrap: true, 
    ),
  ],
)

此外，物理属性可以用来允许/禁止滚动Listview

停止滚动

 ListView(
      shrinkWrap: true, 
      physics: NeverScrollableScrollPhysics(),
    ),

允许滚动

 ListView(
      shrinkWrap: true, 
      physics: ScrollPhysics(),
    ),

2021-06-12 12:57:06

其他回答

    Container(
       height: 100,
       child: ListView.builder(
       scrollDirection: Axis.vertical,
       physics: BouncingScrollPhysics(),
       shrinkWrap: true,
       itemCount: 5,
       itemBuilder: (context, index) {
       return Text("Hello World $index");
      },
    ),
  );

2021-03-13 12:34:14

不要使用Column进行单子对齐。使用Align代替。

new Align(
  alignment: Alignment.topCenter,
  child: new GridView(),
)

2018-05-09 11:48:01

这通常发生在你试图在一个列中使用一个ListView/GridView时，有很多方法来解决它，我在这里列出了几个。

将ListView包装为Expanded 列( 孩子们:<部件> ( Expanded(// wrap in Expanded . 孩子:列表视图(…), )， ), ）在sizebox中包装ListView并给出一个有界的高度列( 孩子们:<部件> ( SizedBox ( 高度:400，//固定高度孩子:列表视图(…), )， ), ）在ListView中使用shrinkWrap: true。列( 孩子们:<部件> ( 列表视图( shrinkWrap: true， //使用这个 )， ), ）

2019-08-03 03:18:35

我做了一个自定义函数来解决你的问题。你可以直接在你的代码库中使用这个函数:

Widget horizontalListView(height, width, color, child, margin) {
return Column(
  children: [
    SizedBox(
      height: 200,
      child: ListView.builder(
        itemCount: 10,
        shrinkWrap: true,
        scrollDirection: Axis.horizontal,
        itemBuilder: (context,index) {
          return Container(
            height: height,
            width: width,
            margin: EdgeInsets.all(margin),
            color: color,
            child: child
          );
        }
      ),
    ),
  ],
 );
})

附注:对不起，代码对齐不好。

2022-02-11 04:40:58