---
title: Image
description: Image component doc
wrapperClass: image-demo-wrapper
tags:
  - 'components'
  - 'data'
---

# Image 图片

图片容器，在保留原生 img 的特性下，支持懒加载，自定义占位、加载失败等

## 基本用法

可通过`fit`确定图片如何适应到容器框，同原生 [object-fit](https://developer.mozilla.org/en-US/docs/Web/CSS/object-fit)。

```vue demo
<template>
  <div class="demo-image">
    <div class="block" v-for="fit in fits" :key="fit">
      <span class="demonstration">{{ fit }}</span>
      <rol-image style="width: 100px; height: 100px" :src="url" :fit="fit"></rol-image>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      fits: ['fill', 'contain', 'cover', 'none', 'scale-down'],
      url: 'https://fuss10.elemecdn.com/e/5d/4a731a90594a4af544c0c25941171jpeg.jpeg',
    }
  },
}
</script>
```

## 占位内容

可通过`slot = placeholder`可自定义占位内容

```vue demo
<template>
  <div class="demo-image__placeholder">
    <div class="block">
      <span class="demonstration">默认</span>
      <rol-image :src="src"></rol-image>
    </div>
    <div class="block">
      <span class="demonstration">自定义</span>
      <rol-image :src="src">
        <template #placeholder>
          <div class="image-slot"> 加载中<span class="dot">...</span> </div>
        </template>
      </rol-image>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      src: 'https://cube.elemecdn.com/6/94/4d3ea53c084bad6931a56d5158a48jpeg.jpeg',
    }
  },
}
</script>
```

## 加载失败

可通过`slot = error`可自定义加载失败内容

```vue demo
<template>
  <div class="demo-image__error">
    <div class="block">
      <span class="demonstration">默认</span>
      <rol-image></rol-image>
    </div>
    <div class="block">
      <span class="demonstration">自定义</span>
      <rol-image>
        <template #error>
          <div class="image-slot">
            <rol-icon name="image"></rol-icon>
          </div>
        </template>
      </rol-image>
    </div>
  </div>
</template>
```

## 懒加载

可通过`lazy`开启懒加载功能，当图片滚动到可视范围内才会加载。可通过`scroll-container`来设置滚动容器，若未定义，则为最近一个`overflow`值为`auto`或`scroll`的父元素。

```vue demo
<template>
  <div class="demo-image__lazy">
    <rol-image v-for="url in urls" :key="url" :src="url" lazy></rol-image>
  </div>
</template>

<script>
export default {
  data() {
    return {
      urls: [
        'https://fuss10.elemecdn.com/a/3f/3302e58f9a181d2509f3dc0fa68b0jpeg.jpeg',
        'https://fuss10.elemecdn.com/1/34/19aa98b1fcb2781c4fba33d850549jpeg.jpeg',
        'https://fuss10.elemecdn.com/0/6f/e35ff375812e6b0020b6b4e8f9583jpeg.jpeg',
        'https://fuss10.elemecdn.com/9/bb/e27858e973f5d7d3904835f46abbdjpeg.jpeg',
        'https://fuss10.elemecdn.com/d/e6/c4d93a3805b3ce3f323f7974e6f78jpeg.jpeg',
        'https://fuss10.elemecdn.com/3/28/bbf893f792f03a54408b3b7a7ebf0jpeg.jpeg',
        'https://fuss10.elemecdn.com/2/11/6535bcfb26e4c79b48ddde44f4b6fjpeg.jpeg',
      ],
    }
  },
}
</script>
```

## 大图预览

可通过 `previewSrcList` 开启预览大图的功能。

```vue demo
<template>
  <div class="demo-image__preview">
    <rol-image style="width: 100px; height: 100px" :src="url" :preview-src-list="srcList"> </rol-image>
  </div>
</template>

<script>
export default {
  data() {
    return {
      url: 'https://fuss10.elemecdn.com/e/5d/4a731a90594a4af544c0c25941171jpeg.jpeg',
      srcList: [
        'https://fuss10.elemecdn.com/8/27/f01c15bb73e1ef3793e64e6b7bbccjpeg.jpeg',
        'https://fuss10.elemecdn.com/1/8e/aeffeb4de74e2fde4bd74fc7b4486jpeg.jpeg',
      ],
    }
  },
}
</script>
```

### Attributes

| 参数             | 说明                                                                                                     | 类型                 | 可选值                                     | 默认值                                         |
| ---------------- | -------------------------------------------------------------------------------------------------------- | -------------------- | ------------------------------------------ | ---------------------------------------------- |
| src              | 图片源，同原生                                                                                           | string               | —                                          | -                                              |
| fit              | 确定图片如何适应容器框，同原生 [object-fit](https://developer.mozilla.org/en-US/docs/Web/CSS/object-fit) | string               | fill / contain / cover / none / scale-down | -                                              |
| alt              | 原生 alt                                                                                                 | string               | -                                          | -                                              |
| referrer-policy  | 原生 referrerPolicy                                                                                      | string               | -                                          | -                                              |
| lazy             | 是否开启懒加载                                                                                           | boolean              | —                                          | false                                          |
| scroll-container | 开启懒加载后，监听 scroll 事件的容器                                                                     | string / HTMLElement | —                                          | 最近一个 overflow 值为 auto 或 scroll 的父元素 |
| preview-src-list | 开启图片预览功能                                                                                         | Array                | —                                          | -                                              |
| z-index          | 设置图片预览的 z-index                                                                                   | Number               | —                                          | 2000                                           |

### Events

| 事件名称 | 说明             | 回调参数   |
| -------- | ---------------- | ---------- |
| load     | 图片加载成功触发 | (e: Event) |
| error    | 图片加载失败触发 | (e: Error) |

### Slots

| 名称        | 说明                 |
| ----------- | -------------------- |
| placeholder | 图片未加载的占位内容 |
| error       | 加载失败的内容       |