js+html5实现手机九宫格密码解锁功能

2017年11月30日作者：业余草原文
HTML5真的是很强大，前端时间看到一个canvas实现九宫格的密码解锁。今天抽出时间模仿了一个，特定分享一下！
效果截图如下：
效果看起来还不错吧！
源码如下：
<!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实现网页解锁功能</title>
  <style type="text/css">
    html, body {
      margin: 0;
      padding: 0;
      width: 100%;
      height: 100%;
    }
  </style>
  <script type="text/javascript">
   /**
   * 半径，画布宽度，画布高度，画布x内边距，画布y内边距
   */
    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++) {
         // 计算圆心坐标
          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;//网页可见区域宽
      canvas.width = canvasWidth;
      canvas.height = canvasHeight;
      var cxt = canvas.getContext("2d");
      /**
       * 每行3个圆
       * OffsetX为canvas x方向内边距
       * */
      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();
        }
 
      }
    }
    
    /**
     * 计算选中的密码 
     */
    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;
      }
    }
    
    /**
     * 给画布绑定事件
     */
    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("密码结果是："+pwdArr.join("->"));
        pwdArr=[];
      }, false);
    }
  </script>
</head>
<body>
<canvas id="lockCanvas"></canvas>
</body>
</html>
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持来客网。