调整

public/react/src/modules/courses/coursesDetail/CoursesLeftNav.js

@@ -680,22 +680,26 @@ class Coursesleftnav extends Component{
     //   course_modules:newcourse_modules
     // })
 
-   if(result.source.droppableId==="shixun_homework"||result.source.droppableId==="graduation"||result.source.droppableId==="attachment"){
+		if(result.source.droppableId==="shixun_homework"||result.source.droppableId==="graduation"||result.source.droppableId==="attachment"){
 
-     let url ="/course_second_categories/"+result.draggableId+"/move_category.json"
-     this.droppablepost(url,result.destination.index+1)
-
-   }else if(result.source.droppableId==="board"){
-
-     let url ="/boards/"+result.draggableId+"/move_category.json"
-     this.droppablepost(url,result.destination.index+1)
+			let url ="/course_second_categories/"+result.draggableId+"/move_category.json";
+			if(result.destination.index!=null){
+				this.droppablepost(url,result.destination.index+1)
+			}
+		}else if(result.source.droppableId==="board"){
 
-   }else if(result.source.droppableId==="course_group"){
+			let url ="/boards/"+result.draggableId+"/move_category.json";
+			if(result.destination.index!=null) {
+				this.droppablepost(url, result.destination.index + 1)
+			}
+		}else if(result.source.droppableId==="course_group"){
 			if(result.draggableId!=1){
-				let url ="/course_groups/"+result.draggableId+"/move_category.json"
-				this.droppablepost(url,result.destination.index+1)
+				let url ="/course_groups/"+result.draggableId+"/move_category.json";
+				if(result.destination.index!=null) {
+					this.droppablepost(url, result.destination.index + 1)
+				}
 			}
-   }
+		}
 
   }