全局引入icons

main.js文件引入icons

import * as ELIcons from '@element-plus/icons-vue'
const app = createApp(App)
for (let iconName in ELIcons) {
    app.component(iconName, ELIcons[iconName])
}

插槽使用prefix

      <el-input
        v-model="filterText"
        placeholder="输入关键字进行搜索"
      >
        <template #prefix>
          <el-icon>
            <Search />
          </el-icon>
        </template>
      </el-input>