问题
I am trying to set the width and height of 2 frame layouts which are the containers for 2 fragments, both being children of a Linear Layout.
However whenever I set width and height of the layout with
frameLayout.setLayoutParams(new FrameLayout.LayoutParams(100,100);
it is resulting in a class cast Exception
java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams cannot be cast to android.widget.LinearLayout$LayoutParams
回答1:
use this method ...
.setLayoutParams(new LinearLayout.LayoutParams(100,100);
instead of your method ....
.setLayoutParams(new FrameLayout.LayoutParams(100,100)
Note:- ClassCastException problem happen when your class is different other class, you want to cast....
回答2:
This answer is actually complementary, as some people already explained the solution, but I wanted to clarify the question further more.
As mentioned above, you must set the parameters to the PARENT view and not to the view itself. You said that the FrameLayouts are inside LinearLayouts, so you must set the parameters for that.
That is the reason why you got the exception
java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams cannot be cast to android.widget.LinearLayout$LayoutParams
The compiler is telling you exactly that, you cannot cast FrameLayout parameters to a LinearLayout.
From Android documentation:
LayoutParams are used by views to tell their parents how they want to be laid out. See ViewGroup Layout Attributes for a list of all child view attributes that this class supports.
Hope that clarifies the question even more!
回答3:
The exception report gives you a hint. It looks like the parent layout of your FrameLayout is a LinearLayout. So, you need to set LinearLayout params for your FrameLayout. Try the following:
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(your_width, your_height);
frameLayout.setLayoutParams(lp);
来源：https://stackoverflow.com/questions/40038105/how-to-set-width-and-height-of-framelayout-dynamically-android