## 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

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

:::

### Horizontal scroll

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

```html

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

:::

### 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>
    <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)
      },
      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 |

### 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 | — |