h5使用canvas画布实现手势解锁

var width = $(document).width();
var height = $(document).height() - 40; //减去手机状态栏的高度

//九宫格其实就是九个点，9个点的坐标对象
var lockCicle = {
    x: 0, //x坐标
    y: 0, //y坐标
    color: "#999999",
    state: "1" //状态当前点是否已经被链接过
};

var offset = (width - height) / 2; //计算偏移量
var arr = []; //九个点的坐标数组

//计算九个点坐标的方法
for (var i = 1; i <= 3; i++) {
    //每一行
    for (var j = 1; j <= 3; j++) {
        //每一行的每一个
        var lockCicle = {};
        //横屏
        if (offset > 0) {
            lockCicle.x = (height / 4) * j + Math.abs(offset);
            lockCicle.y = (height / 4) * i;
            lockCicle.state = 0;
            //竖屏
        } else {
            lockCicle.x = (width / 4) * j;
            lockCicle.y = (width / 4) * i + Math.abs(offset);
            lockCicle.state = 0;
        }
        arr.push(lockCicle);
    }
}

//初始化界面的方法
function init() {
    ctx.clearRect(0, 0, width, height); //清空画布
    pointerArr = []; //清楚绘制路径
    for (var i = 0; i < arr.length; i++) {
        arr[i].state = 0; //清除绘制状态
        drawPointer(i);
    }
}

//绘制九宫格解锁界面
function drawPointer(i) {
    ctx.save();
    var radius = 0;
    if (hastouch) {
        radius = width / 12;
    } else {
        radius = 24;
    }
    var _fillStyle = "#dd514c";
    var _strokeStyle = "#dd514c";
    //不同状态显示不同颜色
    if (arr[i].state == 1) {
        _strokeStyle = "#1bd6c5";
    }
    //绘制原点
    ctx.beginPath();
    ctx.fillStyle = _fillStyle;
    ctx.arc(arr[i].x, arr[i].y, 6, 0, Math.PI * 2, false);
    ctx.fill();
    ctx.closePath();
    //绘制圆圈
    ctx.beginPath();
    ctx.strokeStyle = _strokeStyle;
    ctx.lineWidth = 0.3;
    ctx.lineCap = "round";
    ctx.lineJoin = "round";
    ctx.arc(arr[i].x, arr[i].y, radius, 0, Math.PI * 2, false);
    ctx.stroke();
    ctx.closePath();
    ctx.restore();
}

//初始化界面
init();

var pointerArr = []; //连接线点的坐标数组
var startX, startY; //线条起始点
var puts = []; //经过的九个点的数组
var currentPointer; //当前点是否已经连接
var pwd = []; //密码
var confirmPwd = []; //确认密码
var unlockFlag = false; //是否解锁的标志

/**
 ** 绘制链接线的方法，将坐标数组中的点绘制在canvas画布中
 **/
function drawLinePointer(x, y, flag) {
    ctx.clearRect(0, 0, width, height);
    ctx.save();
    ctx.beginPath();
    ctx.strokeStyle = "#1bd6c5";
    ctx.lineWidth = 5;
    ctx.lineCap = "round";
    ctx.lineJoin = "round";
    for (var i = 0; i < pointerArr.length; i++) {
        if (i == 0) {
            ctx.moveTo(pointerArr[i].x, pointerArr[i].y);
        } else {
            ctx.lineTo(pointerArr[i].x, pointerArr[i].y);
        }
    }
    ctx.stroke();
    ctx.closePath();
    ctx.restore();
    for (var i = 0; i < arr.length; i++) {
        drawPointer(i); //绘制圆圈和原点
        if (ctx.isPointInPath(x, y) && currentPointer != i) {
            //判断鼠标点击是否在圆中
            pointerArr.push({
                x: arr[i].x,
                y: arr[i].y
            });
            currentPointer = i;
            puts.push(i + 1);
            startX = arr[i].x;
            startY = arr[i].y;
            arr[i].state = 1;
        }
    }
    if (flag) {
        ctx.save();
        ctx.beginPath();
        ctx.globalCompositeOperation = "destination-over";
        ctx.strokeStyle = "#e2e0e0";
        ctx.lineWidth = 5;
        ctx.lineCap = "round";
        ctx.lineJoin = "round";
        ctx.moveTo(startX, startY);
        ctx.lineTo(x, y);
        ctx.stroke();
        ctx.beginPath();
        ctx.restore();
    }
}

//兼容移动触摸的事件写法
var hastouch = "ontouchstart" in window ? true : false,
    tapstart = hastouch ? "touchstart" : "mousedown",
    tapmove = hastouch ? "touchmove" : "mousemove",
    tapend = hastouch ? "touchend" : "mouseup";

//绑定按下事件
lockCnavs.addEventListener(tapstart, function(e) {
    isMouseDown = true;
    var x1 = hastouch
        ? e.targetTouches[0].pageX
        : e.clientX - canvas.offsetLeft;
    var y1 = hastouch ? e.targetTouches[0].pageY : e.clientY - canvas.offsetTop;
    drawLinePointer(x1, y1, true);
});

//移动时候，将经过的坐标点全部保存起来
lockCnavs.addEventListener(tapmove, function(e) {
    if (isMouseDown) {
        var x1 = hastouch
            ? e.targetTouches[0].pageX
            : e.clientX - canvas.offsetLeft;
        var y1 = hastouch
            ? e.targetTouches[0].pageY
            : e.clientY - canvas.offsetTop;
        drawLinePointer(x1, y1, true);
    }
});

//取消
lockCnavs.addEventListener(tapend, function(e) {
    drawLinePointer(0, 0, false);
    isMouseDown = false;
    pointerArr = [];
    if (puts.length >= 6) {
        alert("你的图案密码是: [   " + puts.join("    >   ") + "   ]");
        if (unlockFlag) {
            //解锁
            unlock();
        } else {
            //设置解锁密码
            settingUnlockPwd();
        }
    } else {
        if (puts.length >= 1) {
            alert("你的图案密码太简单了~~~");
            init();
        }
    }
    puts = [];
});

//设置解锁密码和解锁测试
function settingUnlockPwd() {
    if (pwd.length <= 0) {
        pwd = puts;
        init();
        $("header").text("再次绘制解锁图案");
    } else if (confirmPwd.length <= 0) {
        confirmPwd = puts;
    }
    console.log(pwd + "  " + confirmPwd);
    //笔记两次密码是否正确
    if (pwd.length > 0 && confirmPwd.length > 0) {
        if (compareArr(pwd, confirmPwd)) {
            $("header").text("解锁图案绘制成功");
            init();
        } else {
            $("header").text("两次绘制的解锁图案不一致");
            init();
            confirmPwd = [];
        }
    }
}
//解锁
function unlock() {
    console.log("解锁密码：" + puts + "  " + confirmPwd);
    if (compareArr(puts, confirmPwd)) {
        $("header").text("解锁成功!页面跳转中......");
    } else {
        $("header").text("解锁图案不正确！！！");
        init();
    }
}
$("footer").click(function() {
    if ($(this).text() === "解锁") {
        unlockFlag = true;
        init();
        $("header").text("绘制解锁图案");
    }
});
//比较两个数组（Number）是否相等
function compareArr(arr1, arr2) {
    return arr1.toString() === arr2.toString();
}