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edwardlorilla/index.html

Created June 6, 2021 16:09
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JavaScript+html implements random QR code verification
Raw
index.html
<div class="code">
<input type="text" value="" placeholder="Please enter the verification code (not case sensitive)" class="input-val">
<canvas id="canvas" width="100" height="30"></canvas>
<button class="btn">Submit</button>
</div>
Raw
script.js
$(function(){
var show_num = [];
draw(show_num);
$("#canvas").on('click',function(){
draw(show_num);
})
$(".btn").on('click',function(){
var val = $(".input-val").val().toLowerCase();
var num = show_num.join("");
if(val==''){
alert('Please enter the verification code!');
}else if(val == num){
alert('Submission is successful!');
$(".input-val").val('');
// draw(show_num);
}else{
alert('The verification code is wrong! Please re-enter!');
$(".input-val").val('');
// draw(show_num);
}
})
})
//Generate and render the verification code graphics
function draw(show_num) {
var canvas_width=$('#canvas').width();
var canvas_height=$('#canvas').height();
var canvas = document.getElementById("canvas");//Get the canvas object, actor
var context = canvas.getContext("2d");//Get the canvas drawing environment, the stage where the actors perform
canvas.width = canvas_width;
canvas.height = canvas_height;
var sCode = "a,b,c,d,e,f,g,h,i,j,k,m,n,p,q,r,s,t,u,v,w,x,y,z,A,B,C,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,W,X,Y,Z,1,2,3,4,5,6,7,8,9,0";
var aCode = sCode.split(",");
var aLength = aCode.length;//Get the length of the array
for (var i = 0; i <4; i++) {//The for loop here can control the digits of the verification code (if you want to display 6 digits, change 4 to 6)
var j = Math.floor(Math.random() * aLength);//Get a random index value
// var deg = Math.random() * 30 * Math.PI / 180;//Generate random radians between 0 and 30
var deg = Math.random()-0.5; //Generate a random radian
var txt = aCode[j];//Get a random content
show_num[i] = txt.toLowerCase();
var x = 10 + i * 20;//The x coordinate of the text on the canvas
var y = 20 + Math.random() * 8;//The y coordinate of the text on the canvas
context.font = "bold 23px Microsoft Yahei";
context.translate(x, y);
context.rotate(deg);
context.fillStyle = randomColor();
context.fillText(txt, 0, 0);
context.rotate(-deg);
context.translate(-x, -y);
}
for (var i = 0; i <= 5; i++) {//Display lines on the verification code
context.strokeStyle = randomColor();
context.beginPath();
context.moveTo(Math.random() * canvas_width, Math.random() * canvas_height);
context.lineTo(Math.random() * canvas_width, Math.random() * canvas_height);
context.stroke();
}
for (var i = 0; i <= 30; i++) {//A small dot is displayed on the verification code
context.strokeStyle = randomColor();
context.beginPath();
var x = Math.random() * canvas_width;
var y = Math.random() * canvas_height;
context.moveTo(x, y);
context.lineTo(x + 1, y + 1);
context.stroke();
}
}
//Get random color values
function randomColor() {
var r = Math.floor(Math.random() * 256);
var g = Math.floor(Math.random() * 256);
var b = Math.floor(Math.random() * 256);
return "rgb(" + r + "," + g + "," + b + ")";
}
Raw
scripts
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
Raw
style.css
.input-val {
width: 200px;
height: 32px;
border: 1px solid #ddd;
box-sizing: border-box;
}
#canvas {
vertical-align: middle;
box-sizing: border-box;
border: 1px solid #ddd;
cursor: pointer;
}
.btn {
display: block;
margin-top: 20px;
height: 32px;
width: 100px;
font-size: 16px;
color: #fff;
background-color: #457adb;
border: none;
border-radius: 50px;
}
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