You must call removeView() on the child's parent first 的处理。

这个问题是由于我们想加入的view已经存在parent导致，一般我们只需要调用((ViewGroup)view.getParent()).removeView(view)即可，可是有些时候并不能解决问题。这时候可以参考以下代码。

        if (child.getParent() instanceof ViewGroup) {
            ViewGroup parent = (ViewGroup) child.getParent();
            LayoutTransition layoutTransition = null;
            if (parent.getLayoutTransition() != null) {
                layoutTransition = parent.getLayoutTransition();
                parent.setLayoutTransition(null);
            }
            parent.removeView(child);
            if (layoutTransition != null) {
                parent.setLayoutTransition(layoutTransition);
            }

            if (child.getParent() != null) {
                // LayoutTransition will cause the child to delay removal - cancel it
                ViewGroupUtils.cancelLayoutTransition(parent);
                // fail-safe if view is still attached for any reason
                if (child.getParent() != null && FIELD_VIEW_PARENT != null) {
                    //通过反射直接把parent设为空
                    ReflectionUtils.setFieldValue(child, ReflectionUtils.getPrivateField(View.class, "mParent"), null);
                }
            }

            //还存在parent，暂时放弃= =
            if (child.getParent() != null) {
                return;
            }
        }

 

public boolean cancelLayoutTransition(ViewGroup group) {
            if (group != null) {
                final LayoutTransition layoutTransition = group.getLayoutTransition();
                if (layoutTransition != null && layoutTransition.isRunning() &&
                        METHOD_LAYOUT_TRANSITION_CANCEL != null) {
                    //由于cancel方法是@hide，所以需要反射调用
                    ReflectionUtils.invoke(group.getLayoutTransition(), null, ReflectionUtils.getPrivateMethod(LayoutTransition.class, "cancel"));
                    return true;
                }
            }
            return false;
        }