tyle="color: green">新增</span>
          <span style="color: red"> 删减</span>
          <span style="color: blue">改动</span>
        </b>
      </div>
      <ul>
        <li v-for="(diff, index) in diffItems" :key="index"
            :class="{'diff-green': diff.color === 'green',
                     'diff-red': diff.color === 'red',
                     'diff-blue': diff.color === 'blue'}">
          <!-- 改动时显示旧值->新值 -->
          <span v-if="diff.type==='changed'">
            {