Flex minWidth minHeight

minWidth
这个值并不是给组件自己用的，而是给组件的父容器用的，这是当父容器在布局时，推荐的最小的组件的宽度。请注意，如果你设置了该值的同时也设置了width，那么在布局时如果width大于minWidth，那么最终的宽度是width,如果width小于minWidth，那么最终的宽度是minWidth。以下是API文档。
The minimum recommended width of the component to be considered                
by the parent during layout. This value is in the                              
component's coordinates, in pixels. The default value depends on               
the component's implementation.                                                
                                                                     
If the application developer sets the value of minWidth,                    
the new value is stored in explicitMinWidth. The default value of minWidth     
does not change. As a result, at layout time, if                               
minWidth was explicitly set by the application developer, then the value of    
explicitMinWidth is used for the component's minimum recommended width.        
If minWidth is not set explicitly by the application developer, then the value o
measuredMinWidth is used.                                             
                                                                               
This value is used by the container in calculating                          
the size and position of the component.                                        
It is not used by the component itself in determining                          
its default size.                                                              
Thus this property may not have any effect if parented by                      
Container, or containers that don't factor in                                  
this property.                                                                 
Because the value is in component coordinates,                                 
the true minWidth with respect to its parent                      
is affected by the scaleX property.