一.直接使用canvas实现
原文地址：https://www.jianshu.com/p/800fecd63094
<template>
<view >
<view class="title">请在下面输入签名：</view>
<canvas class="mycanvas" canvas-id="mycanvas" @touchstart="touchstart" @touchmove="touchmove" @touchend="touchend"></canvas>
<view class="footer">
<view class="left" @click="finish">完成</view>
<view class="right" @click="clear">清除</view>
</view>
</view>
</template>
<script>
var x = 20;
var y =20;
export default{
data(){
return {
ctx:'', //绘图图像
points:[] //路径点集合
}
},
onLoad() {
this.ctx = uni.createCanvasContext("mycanvas",this); //创建绘图对象
//设置画笔样式
this.ctx.lineWidth = 4;
this.ctx.lineCap = "round"
this.ctx.lineJoin = "round"
},
methods:{
//触摸开始，获取到起点
touchstart:function(e){
let startX = e.changedTouches[0].x;
let startY = e.changedTouches[0].y;
let startPoint = {X:startX,Y:startY};
/* **************************************************
#由于uni对canvas的实现有所不同，这里需要把起点存起来
* **************************************************/
this.points.push(startPoint);
//每次触摸开始，开启新的路径
this.ctx.beginPath();
},
//触摸移动，获取到路径点
touchmove:function(e){
let moveX = e.changedTouches[0].x;
let moveY = e.changedTouches[0].y;
let movePoint = {X:moveX,Y:moveY};
this.points.push(movePoint); //存点
let len = this.points.length;
if(len>=2){
this.draw(); //绘制路径
}
},
// 触摸结束，将未绘制的点清空防止对后续路径产生干扰
touchend:function(){
this.points=[];
},
/* ***********************************************
# 绘制笔迹
# 1.为保证笔迹实时显示，必须在移动的同时绘制笔迹
# 2.为保证笔迹连续，每次从路径集合中区两个点作为起点（moveTo）和终点(lineTo)
# 3.将上一次的终点作为下一次绘制的起点（即清除第一个点）
************************************************ */
draw: function() {
let point1 = this.points[0]
let point2 = this.points[1]
this.points.shift()
this.ctx.moveTo(point1.X, point1.Y)
this.ctx.lineTo(point2.X, point2.Y)
this.ctx.stroke()
this.ctx.draw(true)
},
//清空画布
clear:function(){
let that = this;
uni.getSystemInfo({
success: function(res) {
let canvasw = res.windowWidth;
let canvash = res.windowHeight;
that.ctx.clearRect(0, 0, canvasw, canvash);
that.ctx.draw(true);
},
})
},
//完成绘画并保存到本地
finish:function(){
uni.canvasToTempFilePath({
canvasId: 'mycanvas',
success: function(res) {
//如果是h5页面，res.tempFilePath为base64
let path = res.tempFilePath;
uni.saveImageToPhotosAlbum({
filePath:path
})
}
})
}
},
}
</script>
<style>
.title{
height:50upx;
line-height: 50upx;
font-size: 16px;
}
.mycanvas{
width: 100%;
height: calc(100vh - 200upx);
background-color: #ECECEC;
}
.footer{
font-size: 16px;
height: 150upx;
display: flex;
justify-content: space-around;
align-items: center;
}
.left,.right{
line-height: 100upx;
height: 100upx;
width: 250upx;
text-align: center;
font-weight: bold;
color: white;
border-radius: 5upx;
}
.left{
background: #007AFF;
}
.right{
background:orange;
}
</style>
二.zwp-draw-pad插件使用
插件地址：https://ext.dcloud.net.cn/plugin?id=4329
<template>
<view class="pageCss">
<zwp-draw-pad ref="zwpDrawPad" :width="500" :height="500" style="background-color: #fff;"/>
<u-button type="primary" @click="clearBtn">清除</u-button>
<u-button type="primary" @click="backoutBtn">撤销</u-button>
<u-button type="primary" @click="saveBtn">保存</u-button>
</view>
</template>
<script>
// 插件地址:https://ext.dcloud.net.cn/plugin?id=4329
export default {
data() {
return {
};
},
methods:{
clearBtn(){
this.$refs.zwpDrawPad.init();
},
backoutBtn(){
this.$refs.zwpDrawPad.back();
},
saveBtn(){
this.$refs.zwpDrawPad.save().then(res=>{
console.log('保存图片的地址', res.tempFilePath)
})
},
},
}
</script>
<style lang="scss">
page{
background: #F7F8F9FF;
}
</style>
三. l-signature插件使用
插件地址：https://test-ext.dcloud.net.cn/plugin?id=4354
演示地址：http://liangei.gitee.io/limeui/#/signature
<template>
<view>
<view class="topBtnBox">
<u-button type="primary" shape="circle" @click="onClick('clear')" class="btnCss btnCssClear">清除</u-button>
<u-button type="primary" shape="circle" @click="onClick('undo')" class="btnCss btnCssBackout">撤消</u-button>
</view>
<view class="signatureCss" style="margin: 0 30rpx;background-color: #fff;border-radius: 20rpx;">
<l-signature
disableScroll
ref="signatureRef"
:penColor="penColor"
:penSize="penSize"
:maxLineWidth="20"
:openSmooth="openSmooth"
></l-signature>
</view>
<view>
<u-button type="primary" shape="circle" @click="onClick('save')" class="btnCss btnCssSave">保存</u-button>
<!-- <u-button type="primary" shape="circle" @click="onClick('openSmooth')">压感关</u-button> -->
</view>
</view>
</template>
<script>
// 插件地址:https://test-ext.dcloud.net.cn/plugin?id=4354
export default {
data() {
return {
penColor: '#454545',
penSize: 5,
url: '',
openSmooth: true
}
},
methods: {
onClick(type) {
if(type == 'openSmooth') {
this.openSmooth = !this.openSmooth
return
}
if (type == 'save') {
this.$refs.signatureRef.canvasToTempFilePath({
success: (res) => {
this.url = res.tempFilePath;
console.log('url',this.url);
}
})
return
}
if (this.$refs.signatureRef)
this.$refs.signatureRef[type]()
}
}
}
</script>
<style lang="scss">
page{
background: #F7F8F9FF;
}
.btnCss{
font-size: 32rpx;
width: 150rpx;
}
.topBtnBox{
display: flex;
margin: 32rpx;
}
.btnCssSave{
width: 200rpx;
margin: 80rpx auto 0;
}
.signatureCss{
height: 750rpx;
}
</style>
lADPKGXzW6VbyfLNCWDNBDg_1080_2400.jpg_720x720q90g.jpg
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