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---
title: BackTop 返回顶部
description: 用于当页面过长往下滑动时，帮助用户快速回到页面顶部。
spline: navigation
isComponent: true
---
< span class = "coverages-badge" style = "margin-right: 10px" >< img src = "https://img.shields.io/badge/coverages%3A%20lines-100%25-blue" /></ span >< span class = "coverages-badge" style = "margin-right: 10px" >< img src = "https://img.shields.io/badge/coverages%3A%20functions-100%25-blue" /></ span >< span class = "coverages-badge" style = "margin-right: 10px" >< img src = "https://img.shields.io/badge/coverages%3A%20statements-100%25-blue" /></ span >< span class = "coverages-badge" style = "margin-right: 10px" >< img src = "https://img.shields.io/badge/coverages%3A%20branches-100%25-blue" /></ span >
## 引入
全局引入，在 miniprogram 根目录下的`app.json`中配置，局部引入，在需要引入的页面或组件的`index.json`中配置。
```json
"usingComponents" : {
"t-back-top" : "tdesign-miniprogram/back-top/back-top" ,
}
```
## 代码演示
< img src = "https://tdesign.gtimg.com/miniprogram/readme/backtop-1.png" width = "375px" height = "50%" >
### 基础返回顶部
{{ base }}
## API
### BackTop Props
名称 | 类型 | 默认值 | 说明 | 必传
-- | -- | -- | -- | --
external-classes | Array | - | 组件类名，分别用于设置外层元素、图标、文本内容等元素类名。`['t-class', 't-class-icon', 't-class-text']` | N
fixed | Boolean | true | 是否绝对定位固定到屏幕右下方 | N
icon | String / Boolean / Object / Slot | true | 图标。值为 `false` 表示不显示图标。不传表示使用默认图标 `'backtop'` | N
text | String | '' | 文案 | N
theme | String | round | 预设的样式类型。可选项：
### BackTop Events
名称 | 参数 | 描述
-- | -- | --
to-top | \- | 点击触发
