比如下面的代码中，想要在对话框标题栏显示修改哪一个用户的密码，content.username是用户名，怎么把它放到title里面组装成字符串？下面这种写法也不行

<template>
    <el-dialog :**title="修改用户密码"+"content.username"** :visible.sync="isChangePasswordDialogVisible.bol">
      <el-form :model="ChangePassword" :rules="rules" ref="editUserForm">
        <el-form-item label="密码" :label-width="formLabelWidth" prop="password">
          <el-input type="password" v-model.trim="ChangePassword.password" auto-complete="off" placeholder="请输入密码"></el-input>
        </el-form-item>
        <el-form-item label="确认密码" :label-width="formLabelWidth" prop="confirmPassword">
          <el-input type="password" v-model.trim="ChangePassword.confirmPassword" auto-complete="off" placeholder="请再次输入密码"></el-input>
        </el-form-item>
      </el-form>
      <div slot="footer" class="dialog-footer">
        <el-button @click="isChangePasswordDialogVisible.bol = false">取 消</el-button>
        <el-button type="primary" @click="changePassword('editUserForm')">确 定</el-button>
      </div>
    </el-dialog>
</template>