## Scrollbar

Used to replace the browser's native scrollbar.

### Basic usage

:::demo Use `height` property to set the height of the scrollbar, or if not set, it adapts according to the parent container height.

```html
<template>
  <el-scrollbar height="400px">
    <p class="item" v-for="item in 20">{{ item }}</p>
  </el-scrollbar>
</template>
```

:::

### Horizontal scroll

:::demo When the element width is greater than the scrollbar width, the horizontal scrollbar is displayed.

```html
<template>
  <el-scrollbar>
    <div class="flex-content">
      <p class="item" v-for="item in 50">{{ item }}</p>
    </div>
  </el-scrollbar>
</template>
```

:::

### Max height

:::demo The scrollbar is displayed only when the element height exceeds the max height.

```html
<template>
  <el-button @click="add">Add Item</el-button>
  <el-button @click="delete">Delete Item</el-button>
  <el-scrollbar max-height="400px">
    <p class="item" v-for="item in count">{{ item }}</p>
  </el-scrollbar>
</template>

<script>
  export default {
    data() {
      return {
        count: 3,
      }
    },
    methods: {
      add() {
        this.count++
      },
      delete() {
        if (this.count > 0) {
          this.count--
        }
      },
    },
  }
</script>
```

:::

### Manual scroll

:::demo Use `setScrollTop` and `setScrollLeft` methods can control scrollbar manually.

```html
<template>
  <el-scrollbar ref="scrollbar" height="400px" always @scroll="scroll">
    <div ref="inner">
      <p class="item" v-for="item in 20">{{ item }}</p>
    </div>
  </el-scrollbar>

  <el-slider
    v-model="value"
    @input="inputSlider"
    :max="max"
    :format-tooltip="formatTooltip"
  ></el-slider>
</template>

<script>
  export default {
    data() {
      return {
        max: 0,
        value: 0,
      }
    },
    mounted() {
      this.max = this.$refs.inner.clientHeight - 380
    },
    methods: {
      inputSlider(value) {
        this.$refs.scrollbar.setScrollTop(value)
      },
      scroll({ scrollTop }) {
        this.value = scrollTop
      },
      formatTooltip(value) {
        return `${value} px`
      },
    },
  }
</script>
```

:::

### Scrollbar Attributes

| Attribute  | Description                                                                                                                     | Type            | Accepted Values | Default |
| ---------- | ------------------------------------------------------------------------------------------------------------------------------- | --------------- | --------------- | ------- |
| height     | height of scrollbar                                                                                                             | string / number | —               | —       |
| max-height | max height of scrollbar                                                                                                         | string / number | —               | —       |
| native     | whether to use the native scrollbar style                                                                                       | boolean         | —               | false   |
| wrap-style | style of warp container                                                                                                         | string          | —               | —       |
| wrap-class | class of warp container                                                                                                         | string          | —               | —       |
| view-style | style of view                                                                                                                   | string          | —               | —       |
| view-class | class of view                                                                                                                   | string          | —               | —       |
| noresize   | do not respond to container size changes, if the container size does not change, it is better to set it to optimize performance | boolean         | —               | false   |
| tag        | element tag of the view                                                                                                         | string          | —               | div     |
| always     | always show scrollbar                                                                                                           | boolean         | —               | false   |
| min-size   | minimum size of scrollbar                                                                                                       | number          | —               | 20      |

### Scrollbar Events

| Event Name | Description             | Parameters                                      |
| ---------- | ----------------------- | ----------------------------------------------- |
| scroll     | triggers when scrolling | distance of scrolling { scrollLeft, scrollTop } |

### Scrollbar Methods

| Method        | Description                     | Parameters           |
| ------------- | ------------------------------- | -------------------- |
| setScrollTop  | Set distance to scroll top      | (scrollTop: number)  |
| setScrollLeft | Set distance to scroll left     | (scrollLeft: number) |
| update        | update scrollbar state manually | —                    |