在使用Andriod Studio进行实践时出现错误：
this view is not constrained. It only has designtime positions, so it will jump to (0,0) at runtime unless you add the constraints less... (Ctrl+F1)
The layout editor allows you to place widgets anywhere on the canvas, and it records the current position with designtime attributes (such as layout_editor_absoluteX). These attributes are not applied at runtime, so if you push your layout on a device, the widgets may appear in a different location than shown in the editor. To fix this, make sure a widget has both horizontal and vertical constraints by dragging from the edge connections. Issue id: MissingConstraints
实际运行结果，所有控件的坐标都跳到（0,0）。
原因是未添加约束条件，在Andriod Studio的可视化开发界面中添加约束条件即可。
