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

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

其他回答

也会遇到这种错误，因为代码是这样的

return Container(
      child: Column(
        children: [
          ListView.separated(
              itemBuilder: (context, index) {
                return CircleManagerSettingItem(widget.membersInfo[index]);
              },
              separatorBuilder: (_, index) => DD(
                    height: 1,
                    paddingLeft: 10,
                    paddingRight: 10,
                  ),
              itemCount: (widget.membersInfo.length)),
        ],
      ),
    );

删除容器内的列，然后确定。

2021-10-13 10:00:54

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

测试第二个列表视图

ListView.builder(
            physics: NeverScrollableScrollPhysics(),

2020-07-11 08:49:01

将网格视图放置在Flexible或Expanded小部件内

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

2018-09-04 18:27:43

    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

垂直视口高度为无界

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