使用qt qscroller 滚动区域，在里面动态增加组件时，增加的组件会覆盖之前组件，增加的组件也会重叠。
使用designer 拖得qscroller ，scroller-area自带一个scroller_area_content得widget，这个widget我使用水平布局layout,出现问题得原因时layout的大小不能自动更新，scroller-area的大小也不能跟着跟新，查看文档如下
If a scroll area is used to display the contents of a widget that
contains child widgets arranged in a layout, it is important to
realize that the size policy of the layout will also determine the
size of the widget. This is especially useful to know if you intend to
dynamically change the contents of the layout. In such cases, setting
the layout's size constraint property to one which provides
constraints on the minimum and/or maximum size of the layout (e.g.,
QLayout::SetMinAndMaxSize) will cause the size of the scroll area to
be updated whenever the contents of the layout changes.
layout->setSizeConstraint(QLayout::SetMinimumSize )在当前ui的构造函数中加上以上代码解决
Constant Value Description
QLayout::SetDefaultConstraint 0 The main widget's minimum size is set to minimumSize(), unless the widget already has a minimum size.
QLayout::SetFixedSize 3 The main widget's size is set to sizeHint(); it cannot be resized at all.
QLayout::SetMinimumSize 2 The main widget's minimum size is set to minimumSize(); it cannot be smaller.
QLayout::SetMaximumSize 4 The main widget's maximum size is set to maximumSize(); it cannot be larger.
QLayout::SetMinAndMaxSize 5 The main widget's minimum size is set to minimumSize() and its maximum size is set to maximumSize().
QLayout::SetNoConstraint 1 The widget is not constrained.