防止快速下拉，多次请求数据

@@ -22,23 +22,27 @@ class GradeController extends Controller {
         this.content = new GetContent();
         this.content.on('search', this.doSearch.bind(this));
         this.page = 1;
+        this.loading = false;
     }
 
     doSearch() {
-        if (!this.end) {
+        if (!this.end && !this.loading) {
             this.page ++;
             this.search(this.page);
         }
     }
 
     search(page) {
+        this.loading = true;
         search('//m.yohobuy.com/home/gradeNew/getHis', {page: page}).then(data => {
             if (data.detailHis <= 0) {
                 this.end = true;
             } else {
                 $('.ul-detail:first').append(hisContent(data));
             }
-        }).catch(() => {});
+        }).catch(() => {}).finally(() => {
+            this.loading = false;
+        });
     }
 }