效果图

<template>
    <el-dialog
      title="修改密码"
      :visible.sync="dialog"
      :before-close="cancel"
      :close-on-click-modal="false"
      width="500px"
      :modal="false"
    >
    <el-form ref="form" :model="frm" :rules="frmRule" label-width="100px" style="width: 90%;margin: 0 auto;padding: 0;">
        <el-form-item label="原密码" prop="oldPasswd">
            <el-input type="password" v-model="frm.oldPasswd" @change="percentage=checkStrong(frm.oldPasswd)" autocomplete="new-password" placeholder="请输入原密码" style="width: 250px"/>
            
        </el-form-item>
        <el-form-item label="新密码" prop="newPasswd">
            <el-input type="password" v-model="frm.newPasswd" autocomplete="new-password" placeholder="请输入新密码 7-20 数字+字母" style="width: 250px"/>
            <el-progress style="width:300px" :percentage="checkStrong(frm.newPasswd)" :color="customColors" :format="format"></el-progress>
        </el-form-item>
        <el-form-item label="确认密码" prop="repeatPasswd">
            <el-input type="password" v-model="frm.repeatPasswd" autocomplete="new-password" placeholder="请输入确认密码" style="width: 250px"/>
            <el-progress style="width:300px" :percentage="checkStrong(frm.repeatPasswd)" :color="customColors" :format="format"></el-progress>
            <div class="ivu-form-item-notice-tip text-danger">{{serverError}}</div>
        </el-form-item>
    </el-form>
    <span slot="footer" class="dialog-footer">
        <el-button @click="cancel">取 消</el-button>
        <el-button type="primary" @click="ok">确 定</el-button>
    </span>
    </el-dialog>
</template>
<script>
import {mapState} from "vuex";
import store from "@/store";
import {getStore} from "@/util/store";
import regexp from '@/utils/regexp'

export default {
    data () {
        return {
            loading: false,
            serverError: '',
            frm: {
                oldPasswd: '',
                newPasswd: '',
                repeatPasswd: ''
            },
            percentage:0,
            customColors: [
                {color: '#f56c6c', percentage: 30},
                {color: '#e6a23c', percentage: 60},
                {color: '#5cb87a', percentage: 80},
                {color: '#5cb87a', percentage: 100}
            ],
            frmRule: {
                oldPasswd: [
                    { required: true, message: '密码不能为空' },
                    { type: 'string', min: 7, message: '密码最少7位' },
                    { type: 'string', max: 20, message: '密码至多20位' }
                ],
                newPasswd: [
                    { required: true, message: '密码不能为空' },
                    { type: 'string', min: 7, message: '密码最少7位' },
                    { type: 'string', max: 20, message: '密码至多20位' },
                    { validator: (rule, value, callback) => {
                        let v1 = 0
                        if (regexp.b01.test(value)) v1++  // b01: /[a-zA-Z]/, // 大小写字母
                        if (regexp.b02.test(value)) v1++  // b02: /[0-9]/, // 数字
                        if (v1 < 2) {return callback(new Error('密码需同时包含数字、字母!'))}
                        // if (!regexp.b04.test(value)) {return callback(new Error('只能包含数字、字母!'))}
                        this.$refs['form'].validateField('repeatPasswd')
                        callback();
                    } }
                ],
                repeatPasswd: [
                    { required: true, message: '密码不能为空' },
                    { validator: (rule, value, callback) => {
                        if (value !== this.frm.newPasswd) { return callback(new Error('两次输入不一致!')) }
                        callback()
                    } }
                ]
            }
        }
    },
    props: {
        flag: { type: Boolean, default: false },
        dialog: { type: Boolean, default: false }
    },
    watch: { // 监听
        flag (n, o) { // 离开时候清空输入框 归来时候初始化值
            if (n !== true) {
                this.$refs['form'].resetFields()
            }
        }
    },
    methods: {
        ok: debounce(function () {
            this.$refs['form'].validate(valid => {
                if (!valid) {return false}
                this.loading = true
                // 提交
            })
        }),
        checkStrong(msg){
            var modes = 0;
            //正则表达式验证符合要求的
            if(msg.length < 1) return modes;
            if(/\d/.test(msg)) modes++; //数字
            if(/[a-z]/.test(msg)) modes++; //小写
            if(/[A-Z]/.test(msg)) modes++; //大写  
            if(/\W/.test(msg)) modes++; //特殊字符
            //逻辑处理
            switch(modes) {
                case 1:
                    return 25;
                    break;
                case 2:
                    return 50;
                    break;
                case 3:
                    return 75;
                case 4:
                    return 100
                    break;
            }
            return modes;
        },
        format(percentage) {
            //逻辑处理
            switch(percentage) {
                case 25:
                    return '弱';
                    break;
                case 50:
                    return '中';
                    break;
                case 75:
                    return '强';
                case 100:
                    return '强'
                    break;
            }
            return percentage;

            // return percentage == 25 ? '满' : `${percentage}%`;
        },
        cancel () {
            this.$refs['form'].resetFields()
            this.$emit('update:dialog', false)
        },
    },
    mounted () {
    }
}
</script>