flutter Pageview组件

组件说明

• PageController的属性说明

PageView，PageController的源码

• 2.1、PageView源码

PageView({
    Key? key,
    this.scrollDirection = Axis.horizontal,//滑动方向
    this.reverse = false,//是否反转，true 从最后一个记0
    PageController? controller,//控制初始化
    this.physics,//滚动方式
    this.pageSnapping = true,//是否有回弹效果
    this.onPageChanged,//监听切换
    List<Widget> children = const <Widget>[],//子组件
    this.dragStartBehavior = DragStartBehavior.start,//处理拖拽开始行为方式
    this.allowImplicitScrolling = false,
    this.restorationId,
    this.clipBehavior = Clip.hardEdge,
  }) : assert(allowImplicitScrolling != null),
       assert(clipBehavior != null),
       controller = controller ?? _defaultPageController,
       childrenDelegate = SliverChildListDelegate(children),
       super(key: key);

• 2.2 PageController的源码

PageController({
    this.initialPage = 0,//初始化第一次默认在第几个
    this.keepPage = true,//是否保存当前 Page 的状态，如果保存，下次回复对应保存的 page，initialPage被忽略，如果为 false 。下次总是从 initialPage 开始
    this.viewportFraction = 1.0,//占屏幕多少，1为占满整个屏幕
  }) : assert(initialPage != null),
       assert(keepPage != null),
       assert(viewportFraction != null),
       assert(viewportFraction > 0.0);

简单demo

return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text("PageView学习"),
        ),
        body: Center(
          child: PageView(
            scrollDirection: Axis.horizontal,
            reverse: false,
            controller: PageController(
              initialPage: 1,
              keepPage: false,
              viewportFraction: 0.8

            ),
            children: [
              Container(
                color: Colors.red,
                child: Text("我是页面0"),
              ),
              Container(
                color: Colors.blue,
                child: Text("我是页面1"),
              ),
              Container(
                color: Colors.green,
                child: Text("我是页面2")
              )
            ],

          ),
        ),
      ),
    );