Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
    Caused by: java.lang.UnsupportedOperationException: Can't convert to color: type=0x2
    解决办法：use a Theme.AppCompat theme

    重写ViewPager的onMeasure方法即可.如下：
    int mHeight = 0;
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            for (int i = 0; i < getChildCount(); i++) {
                    View child = getChildAt(i);
                    child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
                    int h = child.getMeasuredHeight();
                    if (h > mHeight){
                            mHeight = h;
                    }
            }
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(mHeight, MeasureSpec.EXACTLY);
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    The definition of getChildFragmentManager() is:
            Return a private FragmentManager for placing and managing Fragments inside of this Fragment.
    Meanwhile the definition of getFragmentManager() (or in this case getSupportFragmentManager()) is:
            Return the FragmentManager for interacting with fragments associated with this fragment's activity.

    Basically, the difference is that Fragment's now have their own internal FragmentManager that can handle Fragments.
    The child FragmentManager is the one that handles Fragments contained within only the Fragment that it was added to. 
    The other FragmentManager is contained within the entire Activity.

    In this case, what I'm guessing is you've added the Fragments to the Activity's FragmentManager. 
    You get the child FragmentManager which doesn't contain what you are looking for.
    Thus you get the exception because it can't find the Fragment with the given ID 
    because it's in a different FragmentManager.