vue this.$refs undefined

vue this.$refs undefined    vue $refs undefined    vue cannot read properties of undefined    this.$refs.form.validate    vue this.$router.replace    vue3 $refs获取不到    vue this.$refs为空    undefined reference to `_exit'    qt报错undefined reference to    vue.config.js publicpath    vue3 this.$set is not a function    undefined reference to pthread    vue3 this.$refs    ${pagecontext.request.contextpath}    this.$refs[formname].validate    this.$refs.paging.complete    vue 判断undefined    vue3