本文实例为大家分享了微信小程序实现手写签名的具体代码，供大家参考，具体内容如下
本示例具备的功能：
1、笔迹绘制
2、笔迹清空
以下是js代码：
var content = null;
var touchs = [];
var canvasw = 0;
var canvash = 0;
var that = null;
Page({
/**
* 页面的初始数据
*/
data: {
},
// 画布的触摸移动开始手势响应
start: function(event) {
// console.log("触摸开始" + event.changedTouches[0].y)
// console.log("触摸开始" + event.changedTouches[0].x)
//获取触摸开始的 x,y
let point = {
x: event.changedTouches[0].y,
y: event.changedTouches[0].x
}
touchs.push(point)
},
// 画布的触摸移动手势响应
move: function(e) {
let point = {
x: e.touches[0].y,
y: e.touches[0].x
}
touchs.push(point)
if (touchs.length >= 2) {
this.draw(touchs)
}
},
// 画布的触摸移动结束手势响应
end: function(e) {
// console.log("触摸结束" + e)
//清空轨迹数组
for (let i = 0; i < touchs.length; i++) {
touchs.pop()
}
},
/**
* 生命周期函数--监听页面加载
*/
onLoad: function(options) {
that = this
//获得Canvas的上下文
content = wx.createCanvasContext('firstCanvas')
//设置线的颜色
content.setStrokeStyle("#000")
//设置线的宽度
content.setLineWidth(5)
//设置线两端端点样式更加圆润
content.setLineCap('round')
//设置两条线连接处更加圆润
content.setLineJoin('round')
},
/**
* 生命周期函数--监听页面初次渲染完成
*/
onReady: function() {
// 获取画布尺寸
var query = wx.createSelectorQuery()
query.select('#canvas').boundingClientRect()
query.exec(function(res) {
canvasw = res[0].width;
canvash = res[0].height
})
},
//绘制
draw: function(touchs) {
let point1 = touchs[0]
let point2 = touchs[1]
touchs.shift()
content.moveTo(point1.y, point1.x)
content.lineTo(point2.y, point2.x)
content.stroke()
content.draw(true)
},
//清除操作
clearClick: function() {
//清除画布
content.clearRect(0, 0, canvasw, canvash)
content.draw(true)
},
//保存图片
saveClick: function() {
var that = this
wx.canvasToTempFilePath({
canvasId: 'firstCanvas',
success: function(res) {
//打印图片路径
var path = res.tempFilePath
//上传图片
that.uploadSignPic(path)
console.log(path)
}
})
},
/**
* 上传签名图片
*/
uploadSignPic: function(path) {
//具体实现的业务逻辑
}
})
以下是wxml代码：
<!-- 手写界面 -->
<view class='hand_writing_container'>
<view class="tips_title">请在区域内进行签名</view>
<view id="canvas" class="canvas">
<canvas class='firstCanvas'
canvas-id="firstCanvas"
bindtouchmove='move'
bindtouchstart='start'
bindtouchend='end'
disable-scroll='true' >
</canvas>
</view>
<view class="btn_container">
<view class="btn clean" bindtap="clearClick">
<image src="/image/clear.webp"></image>
<text>内容清除</text>
</view>
<view class="btn submit" bindtap="saveClick">
<image src="/image/submit.webp"></image>
<text>确认提交</text>
</view>
</view>
</view>
以下是样式代码：
.hand_writing_container {
width: 100%;
padding: 5.503vh 8.1761vh 0;
box-sizing: border-box;
}
.tips_title {
height: 4.72vh;
line-height: 4.72vh;
margin-bottom: 3.459vh;
font-size: 4.71698vh;
font-family: Source Han Sans CN;
font-weight: 500;
color: rgba(45, 45, 45, 1);
}
.canvas {
width: 100%;
height: 66.194968vh;
margin-bottom: 3.7735849vh;
box-sizing: border-box;
border: 1rpx dashed black;
}
.firstCanvas {
background-color: white;
width: 100%;
height: 100%;
}
.btn_container {
display: flex;
align-items: center;
padding: 0 45.44vh;
box-sizing: border-box;
justify-content: space-between;
}
.btn {
width: 45.597484vh;
height: 13.83647798vh;
padding: 0 11vh;
box-sizing: border-box;
border-radius: 1.572327vh;
display: flex;
justify-content: space-between;
align-items: center;
}
.btn image {
flex: 0 0 4.71698vh;
width: 4.71698vh;
height: 4.71698vh;
display: block;
margin-right: 1.88679vh;
}
.btn text {
flex: 0 0 auto;
height: 4.717vh;
line-height: 4.717vh;
font-size: 4.71698vh;
font-family: Source Han Sans CN;
font-weight: 400;
color: rgba(255, 255, 255, 1);
}
.clean {
background-color: #07c160;
}
.submit {
background-color: #ff3d33;
}
