1.自定义CustomRecyclerViewer在adapter刷新前按快捷键有概率为空，报空指针错误

app/src/main/java/com/ik/mboxlauncher/view/CustomRecyclerViewer.java

@@ -265,11 +265,15 @@ public class CustomRecyclerViewer extends RecyclerView {
                 // 如果获取失败(也就是说需要交给系统来处理焦点， 消耗掉事件，不让系统处理， 并让先前获取焦点的view获取焦点)
                 if (nextFocusView == null) {
                     if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN) {
+                        if(focusedView!=null){
                             focusedView.requestFocus(View.FOCUS_DOWN);
                         }
+                    }
                     if (keyCode == KeyEvent.KEYCODE_DPAD_UP) {
+                        if(focusedView!=null){
                             focusedView.requestFocus(View.FOCUS_UP);
                         }
+                    }
                     return true;
 
                 }