<template> <div class="hello"><!--touchstart,touchmove,touchend,touchcancel 这--> <button type="" v-on:click="clear">清除</button> <button v-on:click="save">保存</button> <canvas id="canvas" width="300" height="600" style="border:1px solid black">Canvas画板</canvas> <img v-bind:src="url" alt=""> </div> </template><script>var draw;
var preHandler = function(e){
e.preventDefault();
}
class Draw {
constructor(el) {
this.el = el this.canvas = document.getElementById(this.el) this.cxt = this.canvas.getContext("2d') this.stage_info = canvas.getBoundingClientRect() this.path = {
beginX: 0, beginY: 0, endX: 0, endY: 0 }
}
init(btn) {
var that = this;
this.canvas.addEventListener('touchstart', function(event) {
document.addEventListener('touchstart', preHandler, false);
that.drawBegin(event) }
) this.canvas.addEventListener('touchend', function(event) {
document.addEventListener('touchend', preHandler, false);
that.drawEnd() }
) this.clear(btn) }
drawBegin(e) {
var that = this;
window.getSelection() ? window.getSelection().removeAllRanges() : document.selection.empty() this.cxt.strokeStyle = "#000" this.cxt.beginPath() this.cxt.moveTo( e.changedTouches[0].clientX - this.stage_info.left, e.changedTouches[0].clientY - this.stage_info.top ) this.path.beginX = e.changedTouches[0].clientX - this.stage_info.left this.path.beginY = e.changedTouches[0].clientY - this.stage_info.top canvas.addEventListener("touchmove",function(){
that.drawing(event) }
) }
drawing(e) {
this.cxt.lineTo( e.changedTouches[0].clientX - this.stage_info.left, e.changedTouches[0].clientY - this.stage_info.top ) this.path.endX = e.changedTouches[0].clientX - this.stage_info.left this.path.endY = e.changedTouches[0].clientY - this.stage_info.top this.cxt.stroke() }
drawEnd() {
document.removeEventListener('touchstart', preHandler, false);
document.removeEventListener('touchend', preHandler, false);
document.removeEventListener('touchmove', preHandler, false);
//canvas.ontouchmove = canvas.ontouchend = null }
clear(btn) {
this.cxt.clearRect(0, 0, 300, 600) }
save(){
return canvas.toDataURL("image/png") }
}
export default {
data () {
return {
msg: 'Welcome to Your Vue.js App', val:true, url:"" }
}
, mounted() {
draw=new Draw('canvas');
draw.init();
}
, methods:{
clear:function(){
draw.clear();
}
, save:function(){
var data=draw.save();
this.url = data;
console.log(data) }
,　　　mutate(word) {
this.$emit("input", word);
}
,}
}
</script> <!-- Add "scoped" attribute to limit CSS to this component only --> <style scoped>h1, h2 {
font-weight: normal;
}
ul {
list-style-type: none;
padding: 0;
}
li {
display: inline-block;
margin: 0 10px;
}
a {
color: #42b983;
}
#canvas {
background: pink;
cursor: default;
}
#keyword-box {
margin: 10px 0;
}
</style>