请在此处检查 ConstraintLayout:

Please check ConstraintLayout here:

https://developer.android.com/training/constraint-layout/index.html

当您将视图放入布局编辑器时，它会留在您离开的位置即使它没有任何限制.然而，这只是为了使编辑更容易；如果运行布局时视图没有约束在设备上，它被绘制在位置 [0,0](左上角).

When you drop a view into the Layout Editor, it stays where you leave it even if it has no constraints. However, this is only to make editing easier; if a view has no constraints when you run your layout on a device, it is drawn at position [0,0] (the top-left corner).

换句话说，这意味着您必须为视图添加至少一个水平和一个垂直约束

In other words, it means you must add at least one horizontal and one vertical constraint for the view