小編給大家分享一下js+html5如何實現手機九宮格密碼解鎖功能，相信大部分人都還不怎么了解，因此分享這篇文章給大家參考一下，希望大家閱讀完這篇文章后大有收獲，下面讓我們一起去了解一下吧！
HTML5真的是很強大，前端時間看到一個canvas實現九宮格的密碼解鎖。今天抽出時間模仿了一個，特定分享一下！
效果截圖如下：
效果看起來還不錯吧！
源碼如下：
<!DOCTYPE html>
<html>
<head lang="zh-CN">
<meta content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0" name="viewport"/>
<meta charset="UTF-8">
<title>html5實現網頁解鎖功能</title>
<style type="text/css">
html, body {
margin: 0;
padding: 0;
width: 100%;
height: 100%;
}
</style>
<script type="text/javascript">
/**
* 半徑，畫布寬度，畫布高度，畫布x內邊距，畫布y內邊距
*/
var R = 26, canvasWidth = 400, canvasHeight = 320, OffsetX = 30, OffsetY = 30;
var circleArr = [];
function createCirclePoint(diffX, diffY) {
for (var row = 0; row < 3; row++) {
for (var col = 0; col < 3; col++) {
// 計算圓心坐標
var Point = {
X: (OffsetX + col * diffX + ( col * 2 + 1) * R),
Y: (OffsetY + row * diffY + (row * 2 + 1) * R)
};
circleArr.push(Point);
}
}
}
window.onload = function () {
var canvas = document.getElementById("lockCanvas");
canvasWidth = document.body.offsetWidth;//網頁可見區域寬
canvas.width = canvasWidth;
canvas.height = canvasHeight;
var cxt = canvas.getContext("2d");
/**
* 每行3個圓
* OffsetX為canvas x方向內邊距
* */
var X = (canvasWidth - 2 * OffsetX - R * 2 * 3) / 2;
var Y = (canvasHeight - 2 * OffsetY - R * 2 * 3) / 2;
createCirclePoint(X, Y);
bindEvent(canvas, cxt);
//CW=2*offsetX+R*2*3+2*X
Draw(cxt, circleArr, [],null);
}
function Draw(cxt, circleArr, pwdArr,touchPoint) {
if (pwdArr.length > 0) {
cxt.beginPath();
for (var i = 0; i < pwdArr.length; i++) {
var pointIndex = pwdArr[i];
cxt.lineTo(circleArr[pointIndex].X, circleArr[pointIndex].Y);
}
cxt.lineWidth = 10;
cxt.strokeStyle = "#627eed";
cxt.stroke();
cxt.closePath();
if(touchPoint!=null){
var lastPointIndex=pwdArr[pwdArr.length-1];
var lastPoint=circleArr[lastPointIndex];
cxt.beginPath();
cxt.moveTo(lastPoint.X,lastPoint.Y);
cxt.lineTo(touchPoint.X,touchPoint.Y);
cxt.stroke();
cxt.closePath();
}
}
for (var i = 0; i < circleArr.length; i++) {
var Point = circleArr[i];
cxt.fillStyle = "#627eed";
cxt.beginPath();
cxt.arc(Point.X, Point.Y, R, 0, Math.PI * 2, true);
cxt.closePath();
cxt.fill();
cxt.fillStyle = "#ffffff";
cxt.beginPath();
cxt.arc(Point.X, Point.Y, R - 3, 0, Math.PI * 2, true);
cxt.closePath();
cxt.fill();
if(pwdArr.indexOf(i)>=0){
cxt.fillStyle = "#627eed";
cxt.beginPath();
cxt.arc(Point.X, Point.Y, R -16, 0, Math.PI * 2, true);
cxt.closePath();
cxt.fill();
}
}
}
/**
* 計算選中的密碼
*/
function getSelectPwd(touches,pwdArr){
for (var i = 0; i < circleArr.length; i++) {
var currentPoint = circleArr[i];
var xdiff = Math.abs(currentPoint.X - touches.pageX);
var ydiff = Math.abs(currentPoint.Y - touches.pageY);
var dir = Math.pow((xdiff * xdiff + ydiff * ydiff), 0.5);
if(dir > R || pwdArr.indexOf(i) >= 0)
continue;
pwdArr.push(i);
break;
}
}
/**
* 給畫布綁定事件
*/
function bindEvent(canvas, cxt) {
var pwdArr = [];
canvas.addEventListener("touchstart", function (e) {
getSelectPwd(e.touches[0],pwdArr);
}, false);
canvas.addEventListener("touchmove", function (e) {
e.preventDefault();
var touches = e.touches[0];
getSelectPwd(touches,pwdArr);
cxt.clearRect(0,0,canvasWidth,canvasHeight);
Draw(cxt,circleArr,pwdArr,{X:touches.pageX,Y:touches.pageY});
}, false);
canvas.addEventListener("touchend", function (e) {
cxt.clearRect(0,0,canvasWidth,canvasHeight);
Draw(cxt,circleArr,pwdArr,null);
alert("密碼結果是："+pwdArr.join("->"));
pwdArr=[];
}, false);
}
</script>
</head>
<body>
<canvas id="lockCanvas"></canvas>
</body>
</html>1、js屬于一種解釋性腳本語言；2、在絕大多數瀏覽器的支持下，js可以在多種平臺下運行，擁有著跨平臺特性；3、js屬于一種弱類型腳本語言，對使用的數據類型未做出嚴格的要求，能夠進行類型轉換，簡單又容易上手；4、js語言安全性高，只能通過瀏覽器實現信息瀏覽或動態交互，從而有效地防止數據的丟失；5、基于對象的腳本語言，js不僅可以創建對象，也能使用現有的對象。
以上是“js+html5如何實現手機九宮格密碼解鎖功能”這篇文章的所有內容，感謝各位的閱讀！相信大家都有了一定的了解，希望分享的內容對大家有所幫助，如果還想學習更多知識，歡迎關注億速云行業資訊頻道！
免責聲明：本站發布的內容（圖片、視頻和文字）以原創、轉載和分享為主，文章觀點不代表本網站立場，如果涉及侵權請聯系站長郵箱：is@yisu.com進行舉報，并提供相關證據，一經查實，將立刻刪除涉嫌侵權內容。
