提示Void function return value is used

来源：2-7 实现用户登录View层

明明是只幼刀

2021-12-26 10:37:28

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>慕课网OA办公系统</title>
    <!--引入样式-->
    <link rel="stylesheet" type="text/css" href="assets/element-plus/index.css">
    <!--引入组件库-->
    <script src="assets/vue/vue.global.js"></script>
    <script src="assets/element-plus/index.full.js"></script>
    <script src="assets/axios/axios.js"></script>
    <style>
        .login-box {
            border: 1px solid #DCDFE6;
            width: 350px;
            margin: 180px auto;
            padding: 35px 35px 15px 35px;
            border-radius: 5px;
            -webkit-border-radius: 5px;
            -moz-border-radius: 5px;
            box-shadow: 0 0 25px #909399;
        }

        .login-title {
            text-align: center;
            margin: 0 auto 40px auto;
            color: #303133;
        }
    </style>
</head>
<body>
<div id="app">
    <!--
        ref - 当前表单的引用
        :model - 当前表单与指定的JSON数据进行绑定
        :rules - 当前表单校验规则的声明
    -->
    <el-form ref="loginForm" label-width="80px" :model="form" :rules="rules" class="login-box">
        <h2 class="login-title">慕课网OA办公系统</h2>
        <!--prop - 指定规则名字-->
        <el-form-item label="账号" prop="username">
            <el-input v-model="form.username" type="text" placeholder="请输入账号"></el-input>
        </el-form-item>
        <el-form-item label="密码" prop="password">
            <el-input v-model="form.password" type="password" placeholder="请输入账号"></el-input>
        </el-form-item>
        <el-form-item>
            <el-button type="primary" style="width: 200px" v-on:click="onSubmit('loginForm')">登录</el-button>
        </el-form-item>
    </el-form>
</div>

<script>
    const Main = {
        data() {
            return {
                form: {
                    username: '',
                    password: ''
                },
                rules: {
                    /*
                    * 规则名:username
                    * 校验规则:required(文本是否留空)
                    * 提示信息:message
                    * 触发条件:trigger: 'blur'(文本框失去焦点)
                    */
                    username: [
                        {
                            required: true,
                            message: '账号不能为空',
                            trigger: 'blur'
                        }
                    ],
                    password: [
                        {
                            required: true,
                            message: '密码不能为空',
                            trigger: 'blur'
                        }
                    ]
                }
            }
        },
        methods: {
            onSubmit: function (formName) {
                // $refs:通过表单名称获取表单对象
                const form = this.$refs[formName];
                // validate:对表单进行校验,返回结果valid
                form.validate((valid) => {
                    if (valid) {
                        console.info("表单校验成功,准备提交数据");
                        const form = this.form;
                        const params = new URLSearchParams();
                        params.append("username", form.username);
                        params.append("password", form.password);

                        axios.post("/api/login", params, {}).then(function (response) {
                            console.info(response);
                        });
                    }
                });
            }
        }
    };

    // 初始化Vue,绑定Main中的数据,利用ElementPlus对#app容器进行重新渲染
    // 使用Vue对象调用createApp方法来创建Vue应用实例并绑定数据
    const app = Vue.createApp(Main);
    // 调用use方法使用ElementPlus进行渲染
    app.use(ElementPlus);
    // 调用mount方法将应用挂载到页面上
    app.mount("#app");
</script>
</body>
</html>