<view class="electronicSignature">
<!-- <view class="handTitle">手写板</view> -->
<view class="handCanvas" >
<canvas class="writingwrapper" disable-scroll="true" bindtouchstart="uploadScaleStart" bindtouchmove="uploadScaleMove" bindtouchend="uploadScaleEnd" bindtap="mouseDown" canvas-id="writingwrapper"></canvas>
<view class="bottom">
<view>签</view>
<view>名</view>
<view>区</view>
<view>域</view>
</view>
</view>
<view class="handBtn">
<view class="btn" catchtap="cancelDraw">取消</view>
<view class="btn again" catchtap="retDraw"> 重新签名</view>
<view class="btn confirm" catchtap="subCanvas"> 确认签名</view>
</view>
</view>
view{
box-sizing: border-box;
}
.electronicSignature {
background: #fff;
width: 100vw;
height: 100vh;
position: fixed;
top: 0;
z-index: 99998;
left: 0;
display: flex;
flex-direction: column;
}
.handTitle{
text-align: center;
}
.handCanvas{
width: 100%;
padding: 162rpx 62rpx 0;
/* height: calc(100% - 329rpx); */
flex: 1;
position: relative;
}
.writingwrapper{
/* margin-top: 2vh; */
width: 100%;
/* height: 70vh; */
border: 1px solid #CED2D9;
overflow: hidden;
box-sizing: border-box;
border-radius: 24rpx;
height: 100%;
background-color: rgba(0,0,0,0);
}
.handBtn {
padding: 60rpx 75rpx 120rpx;
width: 100%;
display: flex;
justify-content: space-between;
}
.handBtn .btn {
height: 90rpx;
line-height: 90rpx;
font-size: 28rpx;
border-radius: 45rpx;
width:25%;
text-align: center;
}
.handBtn .again {
border: 1px solid #006AE9;
color: #006AE9;
width:33%;
}
.handBtn .confirm {
/* border: 2.95px solid #006AE9; */
background-color: #006AE9;
color: #fff;
width:33%;
}
.delBtn {
color: #666;
}
.subBtn {
background: #008ef6;
color: #fff;
margin-left: 15vw;
}
.bottom{
position: absolute;
width: 100%;
height: 100%;
z-index: -1;
display: flex;
flex-direction: column;
padding: 180rpx 150rpx 0;
align-items: center;
justify-content: center;
font-size: 85rpx;
/* font-weight: 600; */
left: 0;
top: 0;
color: #CED2D9;
}
class Handwriting {
// 内置数据
canvasName = 'writingwrapper';
ctx = '';
canvasWidth = 300;
canvasHeight = 900;
linePrack = []; //划线轨迹 ; 生成线条的实际点
currentLine = [];
transparent = 1; // 透明度
pressure = 0.5; // 默认压力
smoothness = 100; //顺滑度，用60的距离来计算速度
lineSize = 1.5; // 笔记倍数
lineMin = 0.5; // 最小笔画半径
lineMax = 2; // 最大笔画半径
currentPoint = {};
firstTouch = true; // 第一次触发
radius = 1; //画圆的半径
cutArea = {
top: 0,
right: 0,
bottom: 0,
left: 0
}; //裁剪区域
lastPoint = 0;
chirography = []; //笔迹
startY = 0;
deltaY = 0;
startValue = 0;
constructor(pageContext, opts) {
this.page = pageContext
this.lineColor = opts.lineColor || '#1A1A1A' // 颜色
this.slideValue = opts.slideValue || 50
this.init()
this.page.uploadScaleStart = this.uploadScaleStart.bind(this); // 笔迹开始
this.page.uploadScaleMove = this.uploadScaleMove.bind(this); // 笔迹移动
this.page.uploadScaleEnd = this.uploadScaleEnd.bind(this); // 笔迹结束
}
init() {
this.ctx = wx.createCanvasContext(this.canvasName, this.page )
var query = wx.createSelectorQuery();
query.select('.writingwrapper').boundingClientRect(rect => {
// this.canvasWidth = rect.width;
// this.canvasHeight = rect.height;
this.canvasWidth = 90;
this.canvasHeight = 40;
}).exec();
this.selectSlideValue(this.slideValue);
}
// 笔迹开始
uploadScaleStart(e) {
console.log(e.touches[0])
if (e.type != 'touchstart') return false;
this.ctx.setFillStyle(this.lineColor); // 初始线条设置颜色
this.ctx.setGlobalAlpha(this.transparent); // 设置半透明
this.currentPoint = {
x: e.touches[0].x,
y: e.touches[0].y
}
this.currentLine.unshift({
time: new Date().getTime(),
dis: 0,
x: this.currentPoint.x,
y: this.currentPoint.y
})
if (this.firstTouch) {
this.cutArea = {
top: this.currentPoint.y,
right: this.currentPoint.x,
bottom: this.currentPoint.y,
left: this.currentPoint.x
}
this.firstTouch = false
}
this.pointToLine(this.currentLine);
}
// 笔迹移动
uploadScaleMove(e) {
if (e.type != 'touchmove') return false;
if (e.cancelable) {
// 判断默认行为是否已经被禁用
if (!e.defaultPrevented) {
e.preventDefault();
}
}
let point = {
x: e.touches[0].x,
y: e.touches[0].y
}
//测试裁剪
if (point.y < this.cutArea.top) {
this.cutArea.top = point.y;
}
if (point.y < 0) this.cutArea.top = 0;
if (point.x > this.cutArea.right) {
this.cutArea.right = point.x;
}
if (this.canvasWidth - point.x <= 0) {
this.cutArea.right = this.canvasWidth;
}
if (point.y > this.cutArea.bottom) {
this.cutArea.bottom = point.y;
}
if (this.canvasHeight - point.y <= 0) {
this.cutArea.bottom = this.canvasHeight;
}
if (point.x < this.cutArea.left) {
this.cutArea.left = point.x;
}
if (point.x < 0) this.cutArea.left = 0;
this.lastPoint = this.currentPoint;
this.currentPoint = point
this.currentLine.unshift({
time: new Date().getTime(),
dis: this.distance(this.currentPoint, this.lastPoint, 'move'),
x: point.x,
y: point.y
})
this.pointToLine(this.currentLine);
}
// 笔迹结束
uploadScaleEnd(e) {
if (e.type != 'touchend') return 0;
let point = {
x: e.changedTouches[0].x,
y: e.changedTouches[0].y
}
this.lastPoint = this.currentPoint;
this.currentPoint = point
this.currentLine.unshift({
time: new Date().getTime(),
dis: this.distance(this.currentPoint, this.lastPoint, 'end'),
x: point.x,
y: point.y
})
if (this.currentLine.length > 2) {
var info = (this.currentLine[0].time - this.currentLine[this.currentLine.length - 1].time) / this.currentLine.length;
//$("#info").text(info.toFixed(2));
}
//一笔结束，保存笔迹的坐标点，清空，当前笔迹
//增加判断是否在手写区域；
this.pointToLine(this.currentLine);
var currentChirography = {
lineSize: this.lineSize,
lineColor: this.lineColor
};
this.chirography.unshift(currentChirography);
this.linePrack.unshift(this.currentLine);
this.currentLine = []
}
retDraw() {
this.ctx.clearRect(0, 0, 700, 730)
this.ctx.draw()
}
//画两点之间的线条；参数为:line，会绘制最近的开始的两个点；
pointToLine(line) {
this.calcBethelLine(line);
// this.calcBethelLine1(line);
return;
}
//计算插值的方式；
calcBethelLine(line) {
if (line.length <= 1) {
line[0].r = this.radius;
return;
}
let x0, x1, x2, y0, y1, y2, r0, r1, r2, len, lastRadius, dis = 0,
time = 0,
curveValue = 0.5;
if (line.length <= 2) {
x0 = line[1].x
y0 = line[1].y
x2 = line[1].x + (line[0].x - line[1].x) * curveValue;
y2 = line[1].y + (line[0].y - line[1].y) * curveValue;
//x2 = line[1].x;
//y2 = line[1].y;
x1 = x0 + (x2 - x0) * curveValue;
y1 = y0 + (y2 - y0) * curveValue;;
} else {
x0 = line[2].x + (line[1].x - line[2].x) * curveValue;
y0 = line[2].y + (line[1].y - line[2].y) * curveValue;
x1 = line[1].x;
y1 = line[1].y;
x2 = x1 + (line[0].x - x1) * curveValue;
y2 = y1 + (line[0].y - y1) * curveValue;
}
//从计算公式看，三个点分别是(x0,y0),(x1,y1),(x2,y2) ；(x1,y1)这个是控制点，控制点不会落在曲线上；实际上，这个点还会手写获取的实际点，却落在曲线上
len = this.distance({
x: x2,
y: y2
}, {
x: x0,
y: y0
}, 'calc');
lastRadius = this.radius;
for (let n = 0; n < line.length - 1; n++) {
dis += line[n].dis;
time += line[n].time - line[n + 1].time;
if (dis > this.smoothness) break;
}
this.radius = Math.min(time / len * this.pressure + this.lineMin, this.lineMax) * this.lineSize
line[0].r = this.radius;
//计算笔迹半径；
if (line.length <= 2) {
r0 = (lastRadius + this.radius) / 2;
r1 = r0;
r2 = r1;
//return;
} else {
r0 = (line[2].r + line[1].r) / 2;
r1 = line[1].r;
r2 = (line[1].r + line[0].r) / 2;
}
let n = 5;
let point = [];
for (let i = 0; i < n; i++) {
let t = i / (n - 1);
let x = (1 - t) * (1 - t) * x0 + 2 * t * (1 - t) * x1 + t * t * x2;
let y = (1 - t) * (1 - t) * y0 + 2 * t * (1 - t) * y1 + t * t * y2;
let r = lastRadius + (this.radius - lastRadius) / n * i;
point.push({
x: x,
y: y,
r: r
});
if (point.length == 3) {
let a = this.ctaCalc(point[0].x, point[0].y, point[0].r, point[1].x, point[1].y, point[1].r, point[2].x, point[2].y, point[2].r);
a[0].color = this.lineColor;
this.bethelDraw(a, 1);
point = [{
x: x,
y: y,
r: r
}];
}
}
}
//求两点之间距离
distance(a, b, type) {
let x = b.x - a.x;
let y = b.y - a.y;
return Math.sqrt(x * x + y * y) * 5;
}
ctaCalc(x0, y0, r0, x1, y1, r1, x2, y2, r2) {
let a = [],
vx01, vy01, norm, n_x0, n_y0, vx21, vy21, n_x2, n_y2;
vx01 = x1 - x0;
vy01 = y1 - y0;
norm = Math.sqrt(vx01 * vx01 + vy01 * vy01 + 0.0001) * 2;
vx01 = vx01 / norm * r0;
vy01 = vy01 / norm * r0;
n_x0 = vy01;
n_y0 = -vx01;
vx21 = x1 - x2;
vy21 = y1 - y2;
norm = Math.sqrt(vx21 * vx21 + vy21 * vy21 + 0.0001) * 2;
vx21 = vx21 / norm * r2;
vy21 = vy21 / norm * r2;
n_x2 = -vy21;
n_y2 = vx21;
a.push({
mx: x0 + n_x0,
my: y0 + n_y0,
color: "#1A1A1A"
});
a.push({
c1x: x1 + n_x0,
c1y: y1 + n_y0,
c2x: x1 + n_x2,
c2y: y1 + n_y2,
ex: x2 + n_x2,
ey: y2 + n_y2
});
a.push({
c1x: x2 + n_x2 - vx21,
c1y: y2 + n_y2 - vy21,
c2x: x2 - n_x2 - vx21,
c2y: y2 - n_y2 - vy21,
ex: x2 - n_x2,
ey: y2 - n_y2
});
a.push({
c1x: x1 - n_x2,
c1y: y1 - n_y2,
c2x: x1 - n_x0,
c2y: y1 - n_y0,
ex: x0 - n_x0,
ey: y0 - n_y0
});
a.push({
c1x: x0 - n_x0 - vx01,
c1y: y0 - n_y0 - vy01,
c2x: x0 + n_x0 - vx01,
c2y: y0 + n_y0 - vy01,
ex: x0 + n_x0,
ey: y0 + n_y0
});
a[0].mx = a[0].mx.toFixed(1);
a[0].mx = parseFloat(a[0].mx);
a[0].my = a[0].my.toFixed(1);
a[0].my = parseFloat(a[0].my);
for (let i = 1; i < a.length; i++) {
a[i].c1x = a[i].c1x.toFixed(1);
a[i].c1x = parseFloat(a[i].c1x);
a[i].c1y = a[i].c1y.toFixed(1);
a[i].c1y = parseFloat(a[i].c1y);
a[i].c2x = a[i].c2x.toFixed(1);
a[i].c2x = parseFloat(a[i].c2x);
a[i].c2y = a[i].c2y.toFixed(1);
a[i].c2y = parseFloat(a[i].c2y);
a[i].ex = a[i].ex.toFixed(1);
a[i].ex = parseFloat(a[i].ex);
a[i].ey = a[i].ey.toFixed(1);
a[i].ey = parseFloat(a[i].ey);
}
return a;
}
bethelDraw(point, is_fill, color) {
this.ctx.beginPath();
this.ctx.moveTo(point[0].mx, point[0].my);
if (undefined != color) {
this.ctx.setFillStyle(color);
this.ctx.setStrokeStyle(color);
} else {
this.ctx.setFillStyle(point[0].color);
this.ctx.setStrokeStyle(point[0].color);
}
for (let i = 1; i < point.length; i++) {
this.ctx.bezierCurveTo(point[i].c1x, point[i].c1y, point[i].c2x, point[i].c2y, point[i].ex, point[i].ey);
}
this.ctx.stroke();
if (undefined != is_fill) {
this.ctx.fill(); //填充图形 ( 后绘制的图形会覆盖前面的图形, 绘制时注意先后顺序 )
}
this.ctx.draw(true)
}
selectColorEvent(lineColor) {
this.lineColor = lineColor;
}
selectSlideValue(slideValue) {
switch (slideValue) {
case 0:
this.lineSize = 0.1;
this.lineMin = 0.1;
this.lineMax = 0.1;
break;
case 25:
this.lineSize = 1;
this.lineMin = 0.5;
this.lineMax = 2;
break;
case 50:
this.lineSize = 1.5;
this.lineMin = 1;
this.lineMax = 3;
break;
case 75:
this.lineSize = 1.5;
this.lineMin = 2;
this.lineMax = 3.5;
break;
case 100:
this.lineSize = 3;
this.lineMin = 2;
this.lineMax = 3.5;
break;
}
}
}
Component({
data: {
},
properties: {
doSignature: { //是否做交易
type: Boolean,
value: false,
observer: function (newVal, oldVal) {
if (newVal && this.electronSignature){
this.electronSignature.retDraw();
}
}
}
},
lifetimes: {
attached: function () {
// 签名部分
this.electronSignature = new Handwriting(this, {});
},
detached: function () {
},
},
ready() {
},
methods: {
cancelDraw(){
this.triggerEvent("cancelDraw")
},
//重写
retDraw() {
this.electronSignature.retDraw()
},
//完成
subCanvas() {
let self = this
wx.canvasToTempFilePath({
canvasId: 'writingwrapper',
success: function (res) {
//签名成功
self.triggerEvent("SignatureFinish",{ 'path':res.tempFilePath})
},fail:(err)=>{
console.log(err)
}
},this)
}
},
})
标签：cutArea,currentLine,point,签字,width,封装,手写,height,line From： https://www.cnblogs.com/qinlinkun/p/18110008