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>以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。
新聞熱點
疑難解答
