<input v-model='password' ref='password' /><script type="text/javascript">new Vue({    el:'.loginDiv',    data:{        password:''     },    methods:{        submitForm:function() {            var sha = hex_sha1(this.password);            this.password = sha;            console.log(this.$refs.password.value)         }     } })</script>為什么我執行submitForm這個函數，改變password，而this.$refs.password.value打印出來的卻不是password的值