Vue3使用el-form实现登录、注册功能，且进行表单验证（Element Plus中的el-form）

<template>
  <el-form :model="form" :rules="rules" ref="loginForm">
    <el-form-item prop="username">
      <el-input v-model="form.username" placeholder="Username"></el-input>
    </el-form-item>
    <el-form-item prop="password">
      <el-input type="password" v-model="form.password" placeholder="Password"></el-input>
    </el-form-item>
    <el-form-item>
      <el-button type="primary" @click="submitForm('loginForm')">Login</el-button>
      <el-button @click="resetForm('loginForm')">Reset</el-button>
    </el-form-item>
  </el-form>
</template>
 
<script setup>
import { reactive, ref } from 'vue';
import { ElMessage } from 'element-plus';
 
const form = reactive({
  username: '',
  password: ''
});
 
const loginForm = ref(null);
 
const validateUsername = (rule, value, callback) => {
  if (value.length < 6) {
    callback(new Error('Username must be at least 6 characters long'));
  } else {
    callback();
  }
};
 
const validatePassword = (rule, value, callback) => {
  if (value.length < 6) {
    callback(new Error('Password must be at least 6 characters long'));
  } else {
    callback();
  }
};
 
const rules = {
  username: [
    { required: true, message: 'Please input username', trigger: 'blur' },
    { validator: validateUsername, trigger: 'blur' }
  ],
  password: [
    { required: true, message: 'Please input password', trigger: 'blur' },
    { validator: validatePassword, trigger: 'blur' }
  ]
};
 
const submitForm = (formName) => {
  loginForm.value.validate((valid) => {
    if (valid) {
      ElMessage.success('Login Success');
      // 实际项目中这里会调用登录API
    } else {
      ElMessage.error('Login Fail');
      return false;
    }
  });
};
 
const resetForm = (formName) => {
  loginForm.value.resetFields();
};
</script>

这个代码实例展示了如何在Vue 3中使用Element Plus的el-form组件来创建一个登录表单，并使用表单验证规则。它包括了用户名和密码的验证，以及登录和重置表单的方法。这个例子简洁明了，并且提供了一个很好的表单验证实践。