某些api成功但是返回数据为空

platformapi/feieapi/feieapi.go

@@ -276,7 +276,7 @@ func (a *API) QueryPrinterStatus(sn string) (status int, err error) {
 	result, err := a.AccessAPI("Open_queryPrinterStatus", map[string]interface{}{
 		"sn": sn,
 	})
-	if err == nil {
+	if err == nil && result != nil {
 		return printStatusMap[result.(string)], nil
 	}
 	return PrinterStatusUnknown, err