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Vue后台实现点击图片放大功能的示例代码

作者:怪哈哈

这篇文章主要为大家详细介绍了如何利用Vue实现点击图片放大功能,文中的示例代码讲解详细,具有一定的借鉴价值,需要的可以参考一下

需求

点击小图可以放大,放大后,通过手势等比例放大缩小、左右切换图、旋转、关闭。由于element-ui版本较低不支持使用图片放大的image组件。

代码

父组件

<template>
	<div>
		<!-- 放大图 -->
		<el-image-viewer v-if="showImg" :on-close="closeViewer"
                     :src="currItem"
                     :url-list="baseInfo.pictureUrlList"/>
		
		<!-- 小图 -->
		<div class="baseBoxPic">
          <div v-for="(item, index) in baseInfo.pictureUrlList" :key="index" class="picBox">
            <img :src="item" class="litPic" @click="bigImg(item)"/>
          </div>
         </div>
	</div>
</template>

<script>
import ElImageViewer from 'base/image/image-viewer'
export default {
	data() {
		return {
			baseInfo: {
				pictureUrlList: []
			},
			showImg: false,
     		currItem: ''
		}
	},
	components: {
   		'ElImageViewer': ElImageViewer
 	},
 	methods: {
  		// 放大
  		bigImg(e) {
    		this.currItem = e
    		this.showImg = true
  		},
  		// 关闭
  		closeViewer() {
    		this.showImg = false
  		},
  	}
}
</script>

子组件

base/image/image-viewer.vue

<template>
  <transition name="viewer-fade">
    <div class="el-image-viewer__wrapper" :style="{ 'z-index': zIndex }">
      <div class="el-image-viewer__mask"></div>
      <!-- CLOSE -->
      <span class="el-image-viewer__btn el-image-viewer__close" @click="hide">
        <i class="el-icon-circle-close"></i>
      </span>
      <!-- ARROW -->
      <template v-if="!isSingle">
        <span class="el-image-viewer__btn el-image-viewer__prev" :class="{ 'is-disabled': !infinite && isFirst }" @click="prev">
          <i class="el-icon-arrow-left" />
        </span>
        <span class="el-image-viewer__btn el-image-viewer__next" :class="{ 'is-disabled': !infinite && isLast }" @click="next">
          <i class="el-icon-arrow-right" />
        </span>
      </template>
      <!-- ACTIONS -->
      <div class="el-image-viewer__btn el-image-viewer__actions">
        <div class="el-image-viewer__actions__inner">
          <i class="el-icon-zoom-out" style="margin-right: 10px;" @click="handleActions('zoomOut')"></i>
          <i class="el-icon-zoom-in" style="margin-right: 10px;" @click="handleActions('zoomIn')"></i>
          <i class="el-icon-refresh" @click="handleActions('clocelise')"></i>
          <i class="el-image-viewer__actions__divider"></i>
          <i :class="mode.icon" @click="toggleMode"></i>
          <i class="el-image-viewer__actions__divider"></i>
          <i class="el-icon-refresh-left" @click="handleActions('anticlocelise')"></i>
          <i class="el-icon-refresh-right" @click="handleActions('clocelise')"></i>
        </div>
      </div>
      <!-- CANVAS -->
      <div class="el-image-viewer__canvas">
        <div v-for="(url, i) in urlList" v-if="i === index">
          <div v-if="isPdf">
            <a target="_blank" :href="currentImg" rel="external nofollow"  style="color: #fff; position: absolute;left: 50%; top: 50%">点击新页面查看</a>
          </div>
          <img v-else ref="img" class="el-image-viewer__img" :key="url" :src="currentImg" :style="imgStyle" @load="handleImgLoad" @error="handleImgError" @mousedown="handleMouseDown">
        </div>
      </div>
    </div>
  </transition>
</template>

<script>
import { on, off } from './dom';
import { rafThrottle, isFirefox } from './util';
import pdf from 'vue-pdf'

const Mode = {
  CONTAIN: {
    name: 'contain',
    icon: 'el-icon-full-screen'
  },
  ORIGINAL: {
    name: 'original',
    icon: 'el-icon-c-scale-to-original'
  }
};
const mousewheelEventName = isFirefox() ? 'DOMMouseScroll' : 'mousewheel';
export default {
  name: 'elImageViewer',
  props: {
    urlList: {
      type: Array,
      default: () => []
    },
    zIndex: {
      type: Number,
      default: 2300
    },
    onSwitch: {
      type: Function,
      default: () => { }
    },
    onClose: {
      type: Function,
      default: () => { }
    }
  },
  data () {
    return {
      index: 0,
      isShow: false,
      infinite: true,
      loading: false,
      mode: Mode.CONTAIN,
      transform: {
        scale: 1,
        deg: 0,
        offsetX: 0,
        offsetY: 0,
        enableTransition: false
      }
    };
  },
  components: {
    pdf
  },
  computed: {
    isSingle () {
      return this.urlList.length <= 1;
    },
    isFirst () {
      return this.index === 0;
    },
    isLast () {
      return this.index === this.urlList.length - 1;
    },
    isPdf() {
      return this.urlList[this.index] && this.urlList[this.index].toString().indexOf('.pdf') !== -1;
    },
    currentImg () {
      return this.urlList[this.index]
    },
    isPdf() {
      return this.urlList[this.index] &&  this.urlList[this.index].toString().indexOf('.pdf')!== -1;
    },
    imgStyle () {
      const { scale, deg, offsetX, offsetY, enableTransition } = this.transform;
      const style = {
        transform: `scale(${scale}) rotate(${deg}deg)`,
        transition: enableTransition ? 'transform .3s' : '',
        'margin-left': `${offsetX}px`,
        'margin-top': `${offsetY}px`
      };
      if (this.mode === Mode.CONTAIN) {
        style.maxWidth = style.maxHeight = '100%';
      }
      return style;
    }
  },
  watch: {
    index: {
      handler: function (val) {
        this.reset();
        this.onSwitch(val);
      }
    },
    currentImg (val) {
      this.$nextTick(_ => {
        const $img = this.$refs.img[0];
        if (!$img.complete) {
          this.loading = true;
        }
      });
    }
  },
  methods: {
    hide () {
      this.deviceSupportUninstall();
      this.onClose();
    },
    deviceSupportInstall () {
      this._keyDownHandler = rafThrottle(e => {
        const keyCode = e.keyCode;
        switch (keyCode) {
          // ESC
          case 27:
            this.hide();
            break;
          // SPACE
          case 32:
            this.toggleMode();
            break;
          // LEFT_ARROW
          case 37:
            this.prev();
            break;
          // UP_ARROW
          case 38:
            this.handleActions('zoomIn');
            break;
          // RIGHT_ARROW
          case 39:
            this.next();
            break;
          // DOWN_ARROW
          case 40:
            this.handleActions('zoomOut');
            break;
        }
      });
      this._mouseWheelHandler = rafThrottle(e => {
        const delta = e.wheelDelta ? e.wheelDelta : -e.detail;
        if (delta > 0) {
          this.handleActions('zoomIn', {
            zoomRate: 0.015,
            enableTransition: false
          });
        } else {
          this.handleActions('zoomOut', {
            zoomRate: 0.015,
            enableTransition: false
          });
        }
      });
      on(document, 'keydown', this._keyDownHandler);
      on(document, mousewheelEventName, this._mouseWheelHandler);
    },
    deviceSupportUninstall () {
      off(document, 'keydown', this._keyDownHandler);
      off(document, mousewheelEventName, this._mouseWheelHandler);
      this._keyDownHandler = null;
      this._mouseWheelHandler = null;
    },
    handleImgLoad (e) {
      this.loading = false;
    },
    handleImgError (e) {
      this.loading = false;
      e.target.alt = '加载失败';
    },
    handleMouseDown (e) {
      if (this.loading || e.button !== 0) return;
      const { offsetX, offsetY } = this.transform;
      const startX = e.pageX;
      const startY = e.pageY;
      this._dragHandler = rafThrottle(ev => {
        this.transform.offsetX = offsetX + ev.pageX - startX;
        this.transform.offsetY = offsetY + ev.pageY - startY;
      });
      on(document, 'mousemove', this._dragHandler);
      on(document, 'mouseup', ev => {
        off(document, 'mousemove', this._dragHandler);
      });
      e.preventDefault();
    },
    reset () {
      this.transform = {
        scale: 1,
        deg: 0,
        offsetX: 0,
        offsetY: 0,
        enableTransition: false
      };
    },
    toggleMode () {
      if (this.loading) return;
      const modeNames = Object.keys(Mode);
      const modeValues = Object.values(Mode);
      const index = modeValues.indexOf(this.mode);
      const nextIndex = (index + 1) % modeNames.length;
      this.mode = Mode[modeNames[nextIndex]];
      this.reset();
    },
    prev () {
      if (this.isFirst && !this.infinite) return;
      const len = this.urlList.length;
      this.index = (this.index - 1 + len) % len;
    },
    next () {
      if (this.isLast && !this.infinite) return;
      const len = this.urlList.length;
      this.index = (this.index + 1) % len;
    },
    handleActions (action, options = {}) {
      if (this.loading) return;
      const { zoomRate, rotateDeg, enableTransition } = {
        zoomRate: 0.2,
        rotateDeg: 90,
        enableTransition: true,
        ...options
      };
      const { transform } = this;
      switch (action) {
        case 'zoomOut':
          if (transform.scale > 0.2) {
            transform.scale = parseFloat((transform.scale - zoomRate).toFixed(3));
          }
          break;
        case 'zoomIn':
          transform.scale = parseFloat((transform.scale + zoomRate).toFixed(3));
          break;
        case 'clocelise':
          transform.deg += rotateDeg;
          break;
        case 'anticlocelise':
          transform.deg -= rotateDeg;
          break;
      }
      transform.enableTransition = enableTransition;
    }
  },
  mounted () {
    this.deviceSupportInstall();
  }
};
</script>
<style  scoped>
.el-image__error,
.el-image__inner,
.el-image__placeholder {
  width: 100%;
  height: 100%;
}

.el-image {
  position: relative;
  display: inline-block;
  overflow: hidden;
}

.el-image__inner {
  vertical-align: top;
}

.el-image__inner--center {
  position: relative;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: block;
}

.el-image__error,
.el-image__placeholder {
  background: #f5f7fa;
}

.el-image__error {
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 14px;
  color: #c0c4cc;
  vertical-align: middle;
}

.el-image__preview {
  cursor: pointer;
}

.el-image-viewer__wrapper {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
}

.el-image-viewer__btn {
  position: absolute;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  opacity: 0.8;
  cursor: pointer;
  box-sizing: border-box;
  user-select: none;
}

.el-image-viewer__close {
  top: 40px;
  right: 40px;
  width: 40px;
  height: 40px;
  font-size: 40px;
}

.el-image-viewer__canvas {
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.el-image-viewer__actions {
  left: 50%;
  bottom: 30px;
  transform: translateX(-50%);
  width: 100px;
  height: 44px;
  padding: 0 23px;
  background-color: #606266;
  border-color: #fff;
  border-radius: 22px;
}

.el-image-viewer__actions__inner {
  width: 100%;
  height: 100%;
  text-align: justify;
  cursor: default;
  font-size: 23px;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: space-around;
}

.el-image-viewer__prev {
  left: 40px;
}

.el-image-viewer__next,
.el-image-viewer__prev {
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  font-size: 24px;
  color: #fff;
  background-color: #606266;
  border-color: #fff;
}

.el-image-viewer__next {
  right: 40px;
  text-indent: 2px;
}

.el-image-viewer__mask {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  opacity: 0.5;
  background: #000;
}

.viewer-fade-enter-active {
  animation: viewer-fade-in 0.3s;
}

.viewer-fade-leave-active {
  animation: viewer-fade-out 0.3s;
}

@keyframes viewer-fade-in {
  0% {
    transform: translate3d(0, -20px, 0);
    opacity: 0;
  }

  to {
    transform: translateZ(0);
    opacity: 1;
  }
}

@keyframes viewer-fade-out {
  0% {
    transform: translateZ(0);
    opacity: 1;
  }

  to {
    transform: translate3d(0, -20px, 0);
    opacity: 0;
  }
}
</style>

dom.js

/* istanbul ignore next */

import Vue from 'vue';

const isServer = Vue.prototype.$isServer;
const SPECIAL_CHARS_REGEXP = /([:\-_]+(.))/g;
const MOZ_HACK_REGEXP = /^moz([A-Z])/;
const ieVersion = isServer ? 0 : Number(document.documentMode);

/* istanbul ignore next */
export const on = (function () {
  if (!isServer && document.addEventListener) {
    return function (element, event, handler) {
      if (element && event && handler) {
        element.addEventListener(event, handler, false);
      }
    };
  } else {
    return function (element, event, handler) {
      if (element && event && handler) {
        element.attachEvent('on' + event, handler);
      }
    };
  }
})();

/* istanbul ignore next */
export const off = (function () {
  if (!isServer && document.removeEventListener) {
    return function (element, event, handler) {
      if (element && event) {
        element.removeEventListener(event, handler, false);
      }
    };
  } else {
    return function (element, event, handler) {
      if (element && event) {
        element.detachEvent('on' + event, handler);
      }
    };
  }
})();

util.js

import Vue from 'vue';
import {
  isString,
  isObject
} from './types';

const hasOwnProperty = Object.prototype.hasOwnProperty;

export const isFirefox = function () {
  return !Vue.prototype.$isServer && !!window.navigator.userAgent.match(/firefox/i);
};

export const autoprefixer = function (style) {
  if (typeof style !== 'object') return style;
  const rules = ['transform', 'transition', 'animation'];
  const prefixes = ['ms-', 'webkit-'];
  rules.forEach(rule => {
    const value = style[rule];
    if (rule && value) {
      prefixes.forEach(prefix => {
        style[prefix + rule] = value;
      });
    }
  });
  return style;
};

export function rafThrottle(fn) {
  let locked = false;
  return function (...args) {
    if (locked) return;
    locked = true;
    window.requestAnimationFrame(_ => {
      fn.apply(this, args);
      locked = false;
    });
  };
}

types.js

export function isString(obj) {
  return Object.prototype.toString.call(obj) === '[object String]';
}
export function isObject(obj) {
  return Object.prototype.toString.call(obj) === '[object Object]';
}

到此这篇关于Vue后台实现点击图片放大功能的示例代码的文章就介绍到这了,更多相关Vue点击图片放大内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家!

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