比如下面的代碼中，想要在對話框標題欄顯示修改哪一個用戶的密碼，content.username是用戶名，怎么把它放到title里面組裝成字符串？下面這種寫法也不行

<template>
    <el-dialog :**title="修改用戶密碼"+"content.username"** :visible.sync="isChangePasswordDialogVisible.bol">
      <el-form :model="ChangePassword" :rules="rules" ref="editUserForm">
        <el-form-item label="密碼" :label-width="formLabelWidth" prop="password">
          <el-input type="password" v-model.trim="ChangePassword.password" auto-complete="off" placeholder="請輸入密碼"></el-input>
        </el-form-item>
        <el-form-item label="確認密碼" :label-width="formLabelWidth" prop="confirmPassword">
          <el-input type="password" v-model.trim="ChangePassword.confirmPassword" auto-complete="off" placeholder="請再次輸入密碼"></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')">確 定</el-button>
      </div>
    </el-dialog>
</template>