一个Activity中添加多个fragment导致fitsSystemWindows只在第一个起作用

解决办法

自定义frameLayout继承自FrameLayout

public class WindowInsetsFrameLayout extends FrameLayout {
    public WindowInsetsFrameLayout(Context context) {
        this(context, null);
    }

    public WindowInsetsFrameLayout(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public WindowInsetsFrameLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        setOnHierarchyChangeListener(new OnHierarchyChangeListener() {
            @Override
            public void onChildViewAdded(View parent, View child) {
                requestApplyInsets();
            }

            @Override
            public void onChildViewRemoved(View parent, View child) {
            }
        });
    }

    @TargetApi(Build.VERSION_CODES.KITKAT_WATCH)
    @Override
    public WindowInsets onApplyWindowInsets(WindowInsets insets) {
        int childCount = getChildCount();
        for (int index = 0; index < childCount; index++)
            getChildAt(index).dispatchApplyWindowInsets(insets);
        return insets;
    }
}