更改：项目列表使用topic_id查询时应返回对应的总数

app/controllers/projects_controller.rb

@@ -43,6 +43,9 @@ class ProjectsController < ApplicationController
         # ps = ProjectStatistic.first
         # ps.common_projects_count + ps.mirror_projects_count unless ps.blank?
         @projects.total_count
+      elsif params[:topic_id].present? 
+        topic = ProjectTopic.find_by(id: params[:topic_id])
+        topic&.projects_count || 0
       else
         cate = ProjectCategory.find_by(id: category_id)
         cate&.projects_count || 0