添加登录验证码

public/static/verifycode.js

@@ -0,0 +1,73 @@
+$(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('请输入验证码！');
+        } else if (val == num) {
+            alert('提交成功！');
+            $(".input-val").val('');
+            // draw(show_num);
+        } else {
+            alert('验证码错误！请重新输入！');
+            $(".input-val").val('');
+            // draw(show_num);
+        }
+    })
+})
+//生成并渲染出验证码图形
+function draw(show_num) {
+    var canvas_width = $('#canvas').width();
+    var canvas_height = $('#canvas').height();
+    var canvas = document.getElementById("canvas"); //获取到canvas的对象，演员
+    var context = canvas.getContext("2d"); //获取到canvas画图的环境，演员表演的舞台
+    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; //获取到数组的长度
+    for (var i = 0; i < 4; i++) { //这里的for循环可以控制验证码位数（如果想显示6位数，4改成6即可）
+        var j = Math.floor(Math.random() * aLength); //获取到随机的索引值
+        // var deg = Math.random() * 30 * Math.PI / 180;//产生0~30之间的随机弧度
+        var deg = Math.random() - 0.5; //产生一个随机弧度
+        var txt = aCode[j]; //得到随机的一个内容
+        show_num[i] = txt.toLowerCase();
+        var x = 10 + i * 20; //文字在canvas上的x坐标
+        var y = 20 + Math.random() * 8; //文字在canvas上的y坐标
+        context.font = "bold 23px 微软雅黑";
+        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++) { //验证码上显示线条
+        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++) { //验证码上显示小点
+        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();
+    }
+}
+//得到随机的颜色值
+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 + ")";
+}