canvas原生实现前端网页移动端签名

html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">

这篇文章给大家介绍的文章内容是关于canvas原生实现前端网页移动端签名，适用于vue.js react 等任何框架，有很好的参考价值，希望可以帮助到有需要的朋友。

let c = document.getElementById("canvas")
let canvas = document.createElement("canvas")
let availHeight = document.documentElement.clientHeight
let off = availHeight - 400
canvas.height = '350'
canvas.width = c.clientWidth
c.appendChild(canvas)
let dr = canvas.getContext('2d')
dr.strokeStyle = 'blue'
canvas.addEventListener('touchstart',(e)=>{
  dr.beginPath()
  dr.moveTo(e.changedTouches["0"].pageX,e.changedTouches["0"].pageY-off)
})
canvas.addEventListener('touchmove',(e)=>{
  dr.lineTo(e.changedTouches[0].pageX, e.changedTouches[0].pageY-off)
  dr.stroke()
})
canvas.addEventListener('touchend',(e)=>{
  dr.closePath()
})

生成图片

let img = document.querySelector('canvas').toDataURL()

如需发送给后端，可以让后端支持base64或者blob、buffer