vue中使用canvas绘制签名
不多说，上代码：
<template>
<div class="sign-canvas">
<canvas
id="canvas"
width="400"
height="600"
@mousedown="canvasDown($event)"
@mousemove="canvasMove($event)"
@mouseup="canvasUp()"
@mouseleave="canvasLeave()"
ref="canvas"
>
抱歉，您的浏览器暂不支持canvas元素
</canvas>
<div class="sign-btn">
<div class="clear" @click="clear">
清空
</div>
<div class="save" @click="save">
保存
</div>
</div>
</div>
</template>
<script>
export default {
mounted() {
this.show();
},
methods:{
show(){
this.canvas = this.$refs.canvas;// 指定canvas
this.ctx = this.canvas.getContext("2d") // 设置2D渲染区域
this.ctx.lineWidth = 5; // 设置线的宽度
},
canvasDown(e) {
this.canvasMoveUse = true;
const canvasX = e.clientX - e.target.offsetLeft + document.documentElement.scrollLeft
const canvasY = e.clientY - e.target.offsetTop + document.documentElement.scrollTop
this.ctx.beginPath() // 移动的起点
this.ctx.moveTo(canvasX, canvasY)
},
canvasMove(e) {
// 只在移动是进行绘制图线
if (this.canvasMoveUse) {
const t = e.target;
let canvasX;
let canvasY;
canvasX = e.clientX - t.offsetLeft + document.documentElement.scrollLeft
canvasY = e.clientY - t.offsetTop + document.documentElement.scrollTop
this.ctx.lineTo(canvasX, canvasY)
this.ctx.stroke()
}
},
canvasUp() {
this.canvasMoveUse = false;
},
canvasLeave() {
this.canvasMoveUse = false;
},
clear(){
this.ctx.clearRect(0, 0, this.ctx.canvas.width, this.ctx.canvas.height)
},
save() {
const imgBase64 = this.$refs.canvas.toDataURL();
console.log(imgBase64);
}
}
}
</script>
<style scoped>
.sign-canvas{
display: flex;
flex-direction: column;
align-items: center;
width: 100%;
height: 100%;
padding: 20px 30px;
}
.sign-canvas canvas{
background-color: #e0e3e5;
}
.sign-btn {
display: flex;
margin:20px 0;
}
.sign-btn div {
width: 175px;
text-align: center;
height: 70px;
line-height: 70px;
color: #FFFFFF;
}
.sign-btn div:active {
background-color: #CCCCCC;
color: #333333;
}
.sign-btn .clear {
background-color: #FF8F58;
}
.sign-btn .save {
background-color: #0599D7;
}
</style>
样式图：
效果图：
