1. fix Call requires API level 17 (current min is 14): android.view.View#getDisplay

2. update readme

README-cn.md

@@ -42,9 +42,10 @@
 然后在dependencies添加:
 ```
 	dependencies {
-	        compile 'com.github.CymChad:BaseRecyclerViewAdapterHelper:v1.9.7'
+	        compile 'com.github.CymChad:BaseRecyclerViewAdapterHelper:2.9.42'
 	}
 ```
+## [androidX 迁移库版本](https://github.com/CymChad/BaseRecyclerViewAdapterHelper/releases/tag/2.9.43-alpha1)
 
 # 如何使用它来创建Adapter？
 ![demo](https://github.com/CymChad/BaseRecyclerViewAdapterHelper/blob/master/demo_res/item_view.png)

README.md

@@ -6,6 +6,8 @@ Powerful and flexible RecyclerAdapter,
 Please feel free to use this. (Welcome to **Star** and **Fork**)  
 
 kotlin demo :[BRVAH_kotlin](https://github.com/AllenCoder/BRVAH_kotlin)
+
+## [androidX refactoring migration version, temporarily unstable](https://github.com/CymChad/BaseRecyclerViewAdapterHelper/releases/tag/2.9.43-alpha1)
 # Document
 - [English](https://github.com/CymChad/BaseRecyclerViewAdapterHelper/wiki)
 - [中文](http://www.jianshu.com/p/b343fcff51b0)

app/src/main/java/com/chad/baserecyclerviewadapterhelper/decoration/GridSectionAverageGapItemDecoration.java

 package com.chad.baserecyclerviewadapterhelper.decoration;
 
 import android.graphics.Rect;
+import android.os.Build;
 import android.support.v7.widget.GridLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.util.DisplayMetrics;
@@ -115,7 +116,9 @@ public class GridSectionAverageGapItemDecoration extends RecyclerView.ItemDecora
 
     private void transformGapDefinition(RecyclerView parent, int spanCount) {
         DisplayMetrics displayMetrics = new DisplayMetrics();
-        parent.getDisplay().getMetrics(displayMetrics);
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
+            parent.getDisplay().getMetrics(displayMetrics);
+        }
         gapHSizePx = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, gapHorizontalDp, displayMetrics);
         gapVSizePx = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, gapVerticalDp, displayMetrics);
         sectionEdgeHPaddingPx = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, sectionEdgeHPaddingDp, displayMetrics);