转自：http://blog.163.com/smilecatflower_18z/blog/static/19262704520120974119643/
最近，在android中用代码动态改变某种布局（组件）的高度时，会遇到如题所示的类转换异常。上网查了一下，如下所示：
These supply parameters to the parent of this view specifying how it should be arranged. There are many subclasses of ViewGroup.LayoutParams, and these correspond to the different subclasses of ViewGroup that are responsible for arranging their children.
So basically, if you are adding a view to another, you MUST set the LayoutParams of the view to the LayoutParams type that the parent uses, or you will get a runtime error.
我是这样理解的，如果你要将一个view添加到另一个布局中，你必须设定该View的布局参数为其父类所使用的布局参数类型。即要在代码中动态改变某组件的高度，其布局参数类型应该是其父类所使用的布局参数类型。
frameLayout.setLayoutParams(ff);
注：其布局参数类型应该线性布局LinearLayout.LayoutParams的类型，而不是帧布局FrameLayout .LayoutParams。