动态搜位置，5千米

application/api/controller/Topicdongtai.php

@@ -953,7 +953,7 @@ class Topicdongtai extends Api
         $location  = $longitude.','.$latitude;
 
         $keyword = input('keyword','');
-        $radius  = 10000;//周边半径
+        $radius  = 5000;//周边半径,最大支持5000
         $page    = input('page',1);
         $page_size = input('listrow',10);