code: def remove_task(self, row, scan=True):
          '''删除下载任务'''
          if row[STATE_COL] == State.UPLOADING:
              self.remove_worker(row[FID_COL], stop=True)
          self.remove_task_db(row[FID_COL])
          tree_iter = row.iter
          if tree_iter:
              self.liststore.remove(tree_iter)
          if scan:
              self.scan_tasks(f remove_task(self, row, scan=True):
          '''删除下载任务'''
          if row[STATE_COL] == State.UPLOADING:
              self.remove_worker(row[FID_COL], stop=True)
          self.remove_task_db(row[FID_COL])
          tree_iter = row.iter
          if tree_iter:
              self.liststore.remove(tree_iter)
          if scan:
              self.scan_tasks()
docs: 删除下载任务