场景

Fabricjs一个简单强大的Canvas绘图库快速入门：

Fabricjs一个简单强大的Canvas绘图库快速入门_BADAO_LIUMANG_QIZHI的博客-CSDN博客

在上面的基础上，在画布上添加完对象之后，可以将整个画布转换成json数据。

然后还可以将json数据反序列成画布。

还可以将画布转换成svg。

注：

博客：
BADAO_LIUMANG_QIZHI的博客_霸道流氓气质_CSDN博客-C#,SpringBoot,架构之路领域博主
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实现

1、将画布序列化成json数据

      //序列化
      var canvasJsonData = JSON.stringify(canvas.toJSON());
      console.log("toJSON="+canvasJsonData);

2、转换成svg

console.log("toSVG="+canvas.toSVG());

3、完整示例代码

<template>
  <div>
    <div>
      <canvas id="c" width="800" height="800"></canvas>
    </div>
  </div>
</template>

<script>
import { fabric } from "fabric";
export default {
  name: "HelloFabric",
  data() {
    return {};
  },
  mounted() {
    this.init();
  },
  methods: {
    init() {
      // create a wrapper around native canvas element (with id="c")
      // 声明画布
      var canvas = new fabric.Canvas("c");

      // //鼠标按下时事件
      // canvas.on('mouse:down', function(options) {
      //   console.log("mouse:down"+options.e.clientX, options.e.clientY)
      // })

      // //鼠标移动时事件
      // canvas.on('mouse:move', function(options) {
      //   console.log("mouse:move"+options.e.clientX, options.e.clientY)
      // })

      // //鼠标抬起时事件
      // canvas.on('mouse:up', function(options) {
      //   console.log("mouse:up"+options.e.clientX, options.e.clientY)
      // })

      // create a rectangle object
      // 绘制图形
      var rect = new fabric.Rect({
        left: 80, //距离画布左侧的距离，单位是像素
        top: 80, //距离画布上边的距离
        fill: "red", //填充的颜色
        width: 20, //方形的宽度
        height: 20, //方形的高度
      });

      // "add" rectangle onto canvas
      //添加图形至画布
      canvas.add(rect);

      //添加图片
      fabric.Image.fromURL('images/light.png', function(oImg) {
        // scale image down, and flip it, before adding it onto canvas
        //缩小图像并翻转它
        oImg.scale(0.5).set('flipX', true);
        canvas.add(oImg);
      });


      //绘制不规则图形
      var path = new fabric.Path('M 0 0 L 200 100 L 170 200 z');
      path.set({ left: 120, top: 120,fill:'red' });
      //选中监听事件
      path.on('selected', function() {
        console.log('selected');
      });

      //对象移动监听事件
      path.on('moving', function() {
        console.log('moving');
      });

      //对象被旋转监听事件
      path.on('rotating', function() {
        console.log('rotating');
      });

      //对象被加入监听事件
      path.on('added', function() {
        console.log('added');
      });

      //对象被移除监听事件
      path.on('removed', function() {
        console.log('removed');
      });

      canvas.add(path);

      //绘制圆形
      var circle = new fabric.Circle({
        radius: 100,
        fill: '#f00',
        scaleY: 0.5,
        originX: 'center', //调整中心点的X轴坐标
        originY: 'center' //调整中心点的Y轴坐标
      });
      //绘制文本
      var text = new fabric.Text('公众号:霸道的程序猿', {
        fontSize: 20,
        originX: 'center',
        originY: 'center'
      })
      //进行组合
      var group = new fabric.Group([circle, text], {
        left: 350,
        top: 200,
        angle: 10
      })
      canvas.add(group);

      //序列化
      var canvasJsonData = JSON.stringify(canvas.toJSON());
      console.log("toJSON="+canvasJsonData);

      //toSVG
      console.log("toSVG="+canvas.toSVG());

    },
  },
};
</script>

4、反序列化Json数据

      var canvas = new fabric.Canvas("c");
      canvas.loadFromJSON('{"objects":[{"type":"rect","left":50,"top":50,"width":20,"height":20,"fill":"green","overlayFill":null,"stroke":null,"strokeWidth":1,"strokeDashArray":null,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"selectable":true,"hasControls":true,"hasBorders":true,"hasRotatingPoint":false,"transparentCorners":true,"perPixelTargetFind":false,"rx":0,"ry":0},{"type":"circle","left":100,"top":100,"width":100,"height":100,"fill":"red","overlayFill":null,"stroke":null,"strokeWidth":1,"strokeDashArray":null,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"selectable":true,"hasControls":true,"hasBorders":true,"hasRotatingPoint":false,"transparentCorners":true,"perPixelTargetFind":false,"radius":50}],"background":"rgba(0, 0, 0, 0)"}');

完整示例代码

<template>
  <div>
    <div>
      <canvas id="c" width="800" height="800"></canvas>
    </div>
  </div>
</template>

<script>
import { fabric } from "fabric";
export default {
  name: "FabricLoadFromJSON",
  data() {
    return {};
  },
  mounted() {
    this.init();
  },
  methods: {
    init() {
      //加载json数据显示
      var canvas = new fabric.Canvas("c");
      canvas.loadFromJSON('{"objects":[{"type":"rect","left":50,"top":50,"width":20,"height":20,"fill":"green","overlayFill":null,"stroke":null,"strokeWidth":1,"strokeDashArray":null,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"selectable":true,"hasControls":true,"hasBorders":true,"hasRotatingPoint":false,"transparentCorners":true,"perPixelTargetFind":false,"rx":0,"ry":0},{"type":"circle","left":100,"top":100,"width":100,"height":100,"fill":"red","overlayFill":null,"stroke":null,"strokeWidth":1,"strokeDashArray":null,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"selectable":true,"hasControls":true,"hasBorders":true,"hasRotatingPoint":false,"transparentCorners":true,"perPixelTargetFind":false,"radius":50}],"background":"rgba(0, 0, 0, 0)"}');

    },
  },
};
</script>