如何获取当前小部件的偏移量 [英] How to get offset of a current widget

问题描述

每当用户按下屏幕时，我都试图绘制一个小部件。
当前，我是通过存储小部件列表来完成此操作的，当ontapup在手势上触发时，我将其添加到小部件列表中。

I am trying to draw a widget whenever a user presses the screen. Currently I am doing this by storing a list of widgets and when ontapup is fired on the gesture i am adding to a list of widgets.

Widget build(BuildContext context) {
Widget draw = new Text("A");
List<Widget> children = new List<Widget>();
return new Scaffold(
  appBar: new AppBar(
    title: const Text('Heading'),
    leading: new Icon(Icons.question_answer),
  ),
  body: new GestureDetector(
    onTapUp: (details) {
      setState(() {
          children.add(new Positioned(
            left: details.globalPosition.dx,
            top: details.globalPosition.dy,
            child: draw,
          ));
         });
    },
    child: new Stack(children: children)
    ...

所以我的代码正在工作，我正在绘制小部件，当我单击但我的问题是，在添加新的Positioned（）进行堆叠时，位置基于不包含appbar偏移量的屏幕。是否可以获取堆叠的初始x / y位置？一种获取appbars高度的方法？我如何获取一个widget的位置或高度/宽度？​​

So my code is working I am drawing the widget when I click but my problem is that when adding the new Positioned() to stack the position is based on the screen which does not include the appbar offset. Is there a way to get the stacks initial x/y position? Or is there a way to get the appbars height? How do I get a widgets position or height/width?

推荐答案

有我需要的相同问题ed创建自己的窗口小部件并使用

Ok for anyone else who has the same issue I needed to create my own widget and use

context.findRenderObject() 

和

globalToLocal()

在一个解决方案中，我只想将FYI全局化为本地是行不通的。

Just FYI global to local did not work while in the one solution I needed to make it its own widget.

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