嘿是我呀
于 2022-10-09 11:41:50 發(fā)布
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分類專欄： 公眾號(hào) uniapp 前端 文章標(biāo)簽： 前端
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引用頁面
<template>
<view>
<signature :showCanvas="showCanvas" @closeCanvas="closeCanvas"></signature>
<u-button @click="sign">簽名</u-button>
</view>
</template>
<script>
import signature from '@/components/signature.vue';
export default {
components: {
signature
},
data() {
return {
//打開canvas繪制簽名
showCanvas: false,
//是否展示操作菜單
completionSignPath: '' //簽名
}
},
methods: {
//隱藏canvas簽名組件
closeCanvas(e) {
this.showCanvas = false;
if (!this.$isEmpty(e)) {
this.completionSignPath = e
}
},
sign() {
this.showCanvas = true;
}
}
}
</script>
sagnature.vue
<template>
<view class="signature-box">
<!-- 簽名 -->
<view class="signature" v-show="showCanvas">
<canvas class="mycanvas" canvas-id="mycanvas" @touchstart="touchstart" @touchmove="touchmove"
@touchend="touchend"></canvas>
<view class="footer">
<u-button @click="finish" type="primary" :plain="true" :ripple="true" ripple-bg-color="#909399">保存
</u-button>
<u-button @click="clear" type="warning" :plain="true" :ripple="true" ripple-bg-color="#909399">清除
</u-button>
<u-button @click="close" type="error" :plain="true" :ripple="true" ripple-bg-color="#909399">關(guān)閉
</u-button>
</view>
</view>
<!-- 簽完名后生成的圖片 -->
<view v-show="SignatureImg" class="SignatureImg">
<image :src="SignatureImg" mode=""></image>
</view>
<!-- 清除簽完名后生成的圖片 -->
<u-button v-show="SignatureImg" @click="obliterate" type="error" :plain="true" :ripple="true"
ripple-bg-color="#909399" size="medium">清除簽名</u-button>
</view>
</template>
<script>
import { pathToBase64 } from '@/common/js/jssdk_image_tools.js'
var x = 20;
var y = 20;
export default {
data() {
return {
//繪圖圖像
ctx: '',
//路徑點(diǎn)集合
points: [],
//簽名圖片
SignatureImg: '',
hasSign: false
};
},
props: ['showCanvas'],
methods: {
//清除簽名的圖片
obliterate() {
if (this.SignatureImg) {
this.SignatureImg = '';
}
this.close();
},
//關(guān)閉并清空畫布
close() {
this.$emit('closeCanvas');
this.clear();
},
//創(chuàng)建并顯示畫布
createCanvas() {
this.ctx = uni.createCanvasContext('mycanvas', this); //創(chuàng)建繪圖對(duì)象
this.ctx.setFillStyle('#000000')
this.ctx.fillStyle = '#000000'
//設(shè)置畫筆樣式
this.ctx.lineWidth = 4;
this.ctx.lineCap = 'round';
this.ctx.lineJoin = 'round';
console.log(this.ctx)
},
//觸摸開始，獲取到起點(diǎn)
touchstart(e) {
let startX = e.changedTouches[0].x;
let startY = e.changedTouches[0].y;
let startPoint = {
X: startX,
Y: startY
};
this.points.push(startPoint);
//每次觸摸開始，開啟新的路徑
this.ctx.beginPath();
},
//觸摸移動(dòng)，獲取到路徑點(diǎn)
touchmove(e) {
let moveX = e.changedTouches[0].x;
let moveY = e.changedTouches[0].y;
let movePoint = {
X: moveX,
Y: moveY
};
this.points.push(movePoint); //存點(diǎn)
let len = this.points.length;
if (len >= 2) {
this.draw(); //繪制路徑
}
},
// 觸摸結(jié)束，將未繪制的點(diǎn)清空防止對(duì)后續(xù)路徑產(chǎn)生干擾
touchend() {
this.points = [];
},
//繪制筆跡
draw() {
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);
this.hasSign = true
},
//清空畫布
clear() {
this.hasSign = false
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);
}
});
},
//完成繪畫并保存到本地
finish() {
if (!this.hasSign) {
uni.showToast({
title: '簽名為空不能保存',
icon: 'none',
duration: 2000
})
return
}
let that = this;
uni.canvasToTempFilePath({
canvasId: 'mycanvas',
success: function(res) {
if(!res || !res.tempFilePath) {
console.log(res.tempFilePath);
that.SignatureImg = res.tempFilePath;
that.$emit('closeCanvas', that.SignatureImg);
that.close();
}else{
//用來解決安卓真機(jī)獲取到的是canvas圖片的臨時(shí)路徑，轉(zhuǎn)成base64格式
pathToBase64(res.tempFilePath).then(re => {
console.log(re);
that.SignatureImg = re;
that.$emit('closeCanvas', that.SignatureImg);
that.close();
})
}
}
}
);
}
},
mounted() {
this.createCanvas();
}
};
</script>
<style lang="less" scoped>
.signature-box {
display: flex;
flex-direction: column;
align-items: center;
background: #fff;
// height: calc(100vh-44rpx);
//簽名模塊
.signature {
position: fixed;
top: 10px;
left: 2%;
z-index: 999;
width: 96%;
//canvas
.mycanvas {
width: 100%;
// height: calc(100vh - 200upx);
height: calc(100vh - 180rpx);
background-color: #fff;
border-radius: 10px 10px 0 0;
}
//底部按鈕
.footer {
font-size: 14px;
height: 150upx;
display: flex;
justify-content: space-around;
align-items: center;
background-color: #fff;
border-radius: 0 0 10px 10px;
border-top: 1px solid #a7a7a733;
}
}
//生成的圖片
.SignatureImg {
image {
width: 750rpx;
height: 750rpx;
}
}
}
</style>
jssdk_image_tools.js（用來解決安卓真機(jī)獲取到的是canvas圖片的臨時(shí)路徑，轉(zhuǎn)成base64格式）
function getLocalFilePath(path) {
if (path.indexOf('_www') === 0 || path.indexOf('_doc') === 0 || path.indexOf('_documents') === 0 || path.indexOf('_downloads') === 0) {
return path
}
if (path.indexOf('file://') === 0) {
return path
}
if (path.indexOf('/storage/emulated/0/') === 0) {
return path
}
if (path.indexOf('/') === 0) {
var localFilePath = plus.io.convertAbsoluteFileSystem(path)
if (localFilePath !== path) {
return localFilePath
} else {
path = path.substr(1)
}
}
return '_www/' + path
}
function dataUrlToBase64(str) {
var array = str.split(',')
return array[array.length - 1]
}
var index = 0
function getNewFileId() {
return Date.now() + String(index++)
}
function biggerThan(v1, v2) {
var v1Array = v1.split('.')
var v2Array = v2.split('.')
var update = false
for (var index = 0; index < v2Array.length; index++) {
var diff = v1Array[index] - v2Array[index]
if (diff !== 0) {
update = diff > 0
break
}
}
return update
}
export function pathToBase64(path) {
return new Promise(function(resolve, reject) {
if (typeof window === 'object' && 'document' in window) {
if (typeof FileReader === 'function') {
var xhr = new XMLHttpRequest()
xhr.open('GET', path, true)
xhr.responseType = 'blob'
xhr.onload = function() {
if (this.status === 200) {
let fileReader = new FileReader()
fileReader.onload = function(e) {
resolve(e.target.result)
}
fileReader.onerror = reject
fileReader.readAsDataURL(this.response)
}
}
xhr.onerror = reject
xhr.send()
return
}
var canvas = document.createElement('canvas')
var c2x = canvas.getContext('2d')
var img = new Image
img.onload = function() {
canvas.width = img.width
canvas.height = img.height
c2x.drawImage(img, 0, 0)
resolve(canvas.toDataURL())
canvas.height = canvas.width = 0
}
img.onerror = reject
img.src = path
return
}
if (typeof plus === 'object') {
plus.io.resolveLocalFileSystemURL(getLocalFilePath(path), function(entry) {
entry.file(function(file) {
var fileReader = new plus.io.FileReader()
fileReader.onload = function(data) {
resolve(data.target.result)
}
fileReader.onerror = function(error) {
reject(error)
}
fileReader.readAsDataURL(file)
}, function(error) {
reject(error)
})
}, function(error) {
reject(error)
})
return
}
if (typeof wx === 'object' && wx.canIUse('getFileSystemManager')) {
wx.getFileSystemManager().readFile({
filePath: path,
encoding: 'base64',
success: function(res) {
resolve('data:image/png;base64,' + res.data)
},
fail: function(error) {
reject(error)
}
})
return
}
reject(new Error('not support'))
})
}
export function base64ToPath(base64) {
return new Promise(function(resolve, reject) {
if (typeof window === 'object' && 'document' in window) {
base64 = base64.split(',')
var type = base64[0].match(/:(.*?);/)[1]
var str = atob(base64[1])
var n = str.length
var array = new Uint8Array(n)
while (n--) {
array[n] = str.charCodeAt(n)
}
return resolve((window.URL || window.webkitURL).createObjectURL(new Blob([array], { type: type })))
}
var extName = base64.split(',')[0].match(/data\:\S+\/(\S+);/)
if (extName) {
extName = extName[1]
} else {
reject(new Error('base64 error'))
}
var fileName = getNewFileId() + '.' + extName
if (typeof plus === 'object') {
var basePath = '_doc'
var dirPath = 'uniapp_temp'
var filePath = basePath + '/' + dirPath + '/' + fileName
if (!biggerThan(plus.os.name === 'Android' ? '1.9.9.80627' : '1.9.9.80472', plus.runtime.innerVersion)) {
plus.io.resolveLocalFileSystemURL(basePath, function(entry) {
entry.getDirectory(dirPath, {
create: true,
exclusive: false,
}, function(entry) {
entry.getFile(fileName, {
create: true,
exclusive: false,
}, function(entry) {
entry.createWriter(function(writer) {
writer.onwrite = function() {
resolve(filePath)
}
writer.onerror = reject
writer.seek(0)
writer.writeAsBinary(dataUrlToBase64(base64))
}, reject)
}, reject)
}, reject)
}, reject)
return
}
var bitmap = new plus.nativeObj.Bitmap(fileName)
bitmap.loadBase64Data(base64, function() {
bitmap.save(filePath, {}, function() {
bitmap.clear()
resolve(filePath)
}, function(error) {
bitmap.clear()
reject(error)
})
}, function(error) {
bitmap.clear()
reject(error)
})
return
}
if (typeof wx === 'object' && wx.canIUse('getFileSystemManager')) {
var filePath = wx.env.USER_DATA_PATH + '/' + fileName
wx.getFileSystemManager().writeFile({
filePath: filePath,
data: dataUrlToBase64(base64),
encoding: 'base64',
success: function() {
resolve(filePath)
},
fail: function(error) {
reject(error)
}
})
return
}
reject(new Error('not support'))
})
}
文章知識(shí)
————————————————
版權(quán)聲明：本文為CSDN博主「嘿是我呀」的原創(chuàng)文章，遵循CC 4.0 BY-SA版權(quán)協(xié)議，轉(zhuǎn)載請(qǐng)附上原文出處鏈接及本聲明。
原文鏈接：https://blog.csdn.net/weixin_42998230/article/details/127223592
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