微信小程序生成带动态参数二维码

首先说一下我的使用场景，用户可根据id生成这一条记录的二维码，其他人扫码直接跳转到小程序，显示这条记录的具体信息。

分两步：第一在微信公众号后台配置，第二利用canvas前端实现二维码展示，并接收参数做下一步处理。

第一步：后台配置

登录微信公众平台，依次点击开发管理 -> 开发设置 -> 扫普通链接二维码打开小程序添加一个规则
二维码就是一个链接，填写你配置好的路径以及需要跳转的小程序功能页面。
需要注意的是，如果你测试选择的体验版，测试链接后携带的参数一定要和生成二维码路径的参数相同，否则会跳转到正式版的页面。

配置好发布，然后就开始打代码了。

第二步：有趣的代码

wxml中声明画布：

引入js

var OR = require('../../../../utils/qrcode.js')

    generateQRCode(e) {        let id = e.currentTarget.dataset.id;        this.createOrCode(配置的链接, 'mycanvas', 300, 300)    },    //生成二维码    createOrCode(url, canvasId, cavW, cavH) {        //调用插件中的draw方法，绘制二维码图片        OR.api.draw(url, canvasId, cavW, cavH);        setTimeout(() => {            this.canvasToTempImage();        }, 1000);    },    canvasToTempImage: function () {        var that = this;        wx.canvasToTempFilePath({            canvasId: 'mycanvas',            success: function (res) {                var tempFilePath = res.tempFilePath;                console.log('生成临时图片路径。。。。', tempFilePath);                that.setData({                    imagePath: tempFilePath,                    orcode:false                });            },            fail: function (res) {                console.log(res);            }        });    }

相应页面接收参数代码如下：

// 获取url参数 支持中文export const GetRequest = (params) => {    let url = params.substring(params.indexOf("?")); //获取url中"?"符后的字串    let theRequest = new Object();    if (url.indexOf("?") != -1) {        let str = url.substr(1);        let strs = str.split("&");        for (let i = 0; i < strs.length; i++) {            theRequest[strs[i].split("=")[0]] = unescape(strs[i].split("=")[1]);        }    }    return theRequest;} onLoad: function (options) {    const param= GetRequest(decodeURIComponent(options.q))  }

这样就可以生成二维码了，且扫描二维码跳转到小程序，相应页面可获取到对应参数，在请求相对应接口或者进行下一步处理。
我美化了一下，点击弹出二维码，可保存图片，也可直接转发给好友。


js如下：

!(function () {  // alignment pattern  var adelta = [    0, 11, 15, 19, 23, 27, 31,    16, 18, 20, 22, 24, 26, 28, 20, 22, 24, 24, 26, 28, 28, 22, 24, 24,    26, 26, 28, 28, 24, 24, 26, 26, 26, 28, 28, 24, 26, 26, 26, 28, 28  ];  // version block  var vpat = [    0xc94, 0x5bc, 0xa99, 0x4d3, 0xbf6, 0x762, 0x847, 0x60d,    0x928, 0xb78, 0x45d, 0xa17, 0x532, 0x9a6, 0x683, 0x8c9,    0x7ec, 0xec4, 0x1e1, 0xfab, 0x08e, 0xc1a, 0x33f, 0xd75,    0x250, 0x9d5, 0x6f0, 0x8ba, 0x79f, 0xb0b, 0x42e, 0xa64,    0x541, 0xc69  ];  // final fORMat bits with mask: level << 3 | mask  var fmtWord = [    0x77c4, 0x72f3, 0x7daa, 0x789d, 0x662f, 0x6318, 0x6c41, 0x6976,    //L    0x5412, 0x5125, 0x5e7c, 0x5b4b, 0x45f9, 0x40ce, 0x4f97, 0x4aa0,    //M    0x355f, 0x3068, 0x3f31, 0x3a06, 0x24b4, 0x2183, 0x2eda, 0x2bed,    //Q    0x1689, 0x13be, 0x1ce7, 0x19d0, 0x0762, 0x0255, 0x0d0c, 0x083b    //H  ];  // 4 per version: number of blocks 1,2; data width; ecc width  var eccblocks = [    1, 0, 19, 7, 1, 0, 16, 10, 1, 0, 13, 13, 1, 0, 9, 17,    1, 0, 34, 10, 1, 0, 28, 16, 1, 0, 22, 22, 1, 0, 16, 28,    1, 0, 55, 15, 1, 0, 44, 26, 2, 0, 17, 18, 2, 0, 13, 22,    1, 0, 80, 20, 2, 0, 32, 18, 2, 0, 24, 26, 4, 0, 9, 16,    1, 0, 108, 26, 2, 0, 43, 24, 2, 2, 15, 18, 2, 2, 11, 22,    2, 0, 68, 18, 4, 0, 27, 16, 4, 0, 19, 24, 4, 0, 15, 28,    2, 0, 78, 20, 4, 0, 31, 18, 2, 4, 14, 18, 4, 1, 13, 26,    2, 0, 97, 24, 2, 2, 38, 22, 4, 2, 18, 22, 4, 2, 14, 26,    2, 0, 116, 30, 3, 2, 36, 22, 4, 4, 16, 20, 4, 4, 12, 24,    2, 2, 68, 18, 4, 1, 43, 26, 6, 2, 19, 24, 6, 2, 15, 28,    4, 0, 81, 20, 1, 4, 50, 30, 4, 4, 22, 28, 3, 8, 12, 24,    2, 2, 92, 24, 6, 2, 36, 22, 4, 6, 20, 26, 7, 4, 14, 28,    4, 0, 107, 26, 8, 1, 37, 22, 8, 4, 20, 24, 12, 4, 11, 22,    3, 1, 115, 30, 4, 5, 40, 24, 11, 5, 16, 20, 11, 5, 12, 24,    5, 1, 87, 22, 5, 5, 41, 24, 5, 7, 24, 30, 11, 7, 12, 24,    5, 1, 98, 24, 7, 3, 45, 28, 15, 2, 19, 24, 3, 13, 15, 30,    1, 5, 107, 28, 10, 1, 46, 28, 1, 15, 22, 28, 2, 17, 14, 28,    5, 1, 120, 30, 9, 4, 43, 26, 17, 1, 22, 28, 2, 19, 14, 28,    3, 4, 113, 28, 3, 11, 44, 26, 17, 4, 21, 26, 9, 16, 13, 26,    3, 5, 107, 28, 3, 13, 41, 26, 15, 5, 24, 30, 15, 10, 15, 28,    4, 4, 116, 28, 17, 0, 42, 26, 17, 6, 22, 28, 19, 6, 16, 30,    2, 7, 111, 28, 17, 0, 46, 28, 7, 16, 24, 30, 34, 0, 13, 24,    4, 5, 121, 30, 4, 14, 47, 28, 11, 14, 24, 30, 16, 14, 15, 30,    6, 4, 117, 30, 6, 14, 45, 28, 11, 16, 24, 30, 30, 2, 16, 30,    8, 4, 106, 26, 8, 13, 47, 28, 7, 22, 24, 30, 22, 13, 15, 30,    10, 2, 114, 28, 19, 4, 46, 28, 28, 6, 22, 28, 33, 4, 16, 30,    8, 4, 122, 30, 22, 3, 45, 28, 8, 26, 23, 30, 12, 28, 15, 30,    3, 10, 117, 30, 3, 23, 45, 28, 4, 31, 24, 30, 11, 31, 15, 30,    7, 7, 116, 30, 21, 7, 45, 28, 1, 37, 23, 30, 19, 26, 15, 30,    5, 10, 115, 30, 19, 10, 47, 28, 15, 25, 24, 30, 23, 25, 15, 30,    13, 3, 115, 30, 2, 29, 46, 28, 42, 1, 24, 30, 23, 28, 15, 30,    17, 0, 115, 30, 10, 23, 46, 28, 10, 35, 24, 30, 19, 35, 15, 30,    17, 1, 115, 30, 14, 21, 46, 28, 29, 19, 24, 30, 11, 46, 15, 30,    13, 6, 115, 30, 14, 23, 46, 28, 44, 7, 24, 30, 59, 1, 16, 30,    12, 7, 121, 30, 12, 26, 47, 28, 39, 14, 24, 30, 22, 41, 15, 30,    6, 14, 121, 30, 6, 34, 47, 28, 46, 10, 24, 30, 2, 64, 15, 30,    17, 4, 122, 30, 29, 14, 46, 28, 49, 10, 24, 30, 24, 46, 15, 30,    4, 18, 122, 30, 13, 32, 46, 28, 48, 14, 24, 30, 42, 32, 15, 30,    20, 4, 117, 30, 40, 7, 47, 28, 43, 22, 24, 30, 10, 67, 15, 30,    19, 6, 118, 30, 18, 31, 47, 28, 34, 34, 24, 30, 20, 61, 15, 30  ];  // Galois field log table  var glog = [    0xff, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6, 0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b,    0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81, 0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71,    0x05, 0x8a, 0x65, 0x2f, 0xe1, 0x24, 0x0f, 0x21, 0x35, 0x93, 0x8e, 0xda, 0xf0, 0x12, 0x82, 0x45,    0x1d, 0xb5, 0xc2, 0x7d, 0x6a, 0x27, 0xf9, 0xb9, 0xc9, 0x9a, 0x09, 0x78, 0x4d, 0xe4, 0x72, 0xa6,    0x06, 0xbf, 0x8b, 0x62, 0x66, 0xdd, 0x30, 0xfd, 0xe2, 0x98, 0x25, 0xb3, 0x10, 0x91, 0x22, 0x88,    0x36, 0xd0, 0x94, 0xce, 0x8f, 0x96, 0xdb, 0xbd, 0xf1, 0xd2, 0x13, 0x5c, 0x83, 0x38, 0x46, 0x40,    0x1e, 0x42, 0xb6, 0xa3, 0xc3, 0x48, 0x7e, 0x6e, 0x6b, 0x3a, 0x28, 0x54, 0xfa, 0x85, 0xba, 0x3D,    0xca, 0x5e, 0x9b, 0x9f, 0x0a, 0x15, 0x79, 0x2b, 0x4e, 0xd4, 0xe5, 0xac, 0x73, 0xf3, 0xa7, 0x57,    0x07, 0x70, 0xc0, 0xf7, 0x8c, 0x80, 0x63, 0x0d, 0x67, 0x4a, 0xde, 0xed, 0x31, 0xc5, 0xfe, 0x18,    0xe3, 0xa5, 0x99, 0x77, 0x26, 0xb8, 0xb4, 0x7c, 0x11, 0x44, 0x92, 0xd9, 0x23, 0x20, 0x89, 0x2e,    0x37, 0x3f, 0xd1, 0x5b, 0x95, 0xbc, 0xcf, 0xcd, 0x90, 0x87, 0x97, 0xb2, 0xdc, 0xfc, 0xbe, 0x61,    0xf2, 0x56, 0xd3, 0xab, 0x14, 0x2a, 0x5d, 0x9e, 0x84, 0x3c, 0x39, 0x53, 0x47, 0x6d, 0x41, 0xa2,    0x1f, 0x2d, 0x43, 0xd8, 0xb7, 0x7b, 0xa4, 0x76, 0xc4, 0x17, 0x49, 0xec, 0x7f, 0x0c, 0x6f, 0xf6,    0x6c, 0xa1, 0x3b, 0x52, 0x29, 0x9d, 0x55, 0xaa, 0xfb, 0x60, 0x86, 0xb1, 0xbb, 0xcc, 0x3e, 0x5a,    0xcb, 0x59, 0x5f, 0xb0, 0x9c, 0xa9, 0xa0, 0x51, 0x0b, 0xf5, 0x16, 0xeb, 0x7a, 0x75, 0x2c, 0xd7,    0x4f, 0xae, 0xd5, 0xe9, 0xe6, 0xe7, 0xad, 0xe8, 0x74, 0xd6, 0xf4, 0xea, 0xa8, 0x50, 0x58, 0xaf  ];  // GaliOS field exponent table  var gexp = [    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1d, 0x3a, 0x74, 0xe8, 0xcd, 0x87, 0x13, 0x26,    0x4c, 0x98, 0x2d, 0x5a, 0xb4, 0x75, 0xea, 0xc9, 0x8f, 0x03, 0x06, 0x0c, 0x18, 0x30, 0x60, 0xc0,    0x9d, 0x27, 0x4e, 0x9c, 0x25, 0x4a, 0x94, 0x35, 0x6a, 0xd4, 0xb5, 0x77, 0xee, 0xc1, 0x9f, 0x23,    0x46, 0x8c, 0x05, 0x0a, 0x14, 0x28, 0x50, 0xa0, 0x5d, 0xba, 0x69, 0xd2, 0xb9, 0x6f, 0xde, 0xa1,    0x5f, 0xbe, 0x61, 0xc2, 0x99, 0x2f, 0x5e, 0xbc, 0x65, 0xca, 0x89, 0x0f, 0x1e, 0x3c, 0x78, 0xf0,    0xfd, 0xe7, 0xd3, 0xbb, 0x6b, 0xd6, 0xb1, 0x7f, 0xfe, 0xe1, 0xdf, 0xa3, 0x5b, 0xb6, 0x71, 0xe2,    0xd9, 0xaf, 0x43, 0x86, 0x11, 0x22, 0x44, 0x88, 0x0d, 0x1a, 0x34, 0x68, 0xd0, 0xbd, 0x67, 0xce,    0x81, 0x1f, 0x3e, 0x7c, 0xf8, 0xed, 0xc7, 0x93, 0x3b, 0x76, 0xec, 0xc5, 0x97, 0x33, 0x66, 0xcc,    0x85, 0x17, 0x2e, 0x5c, 0xb8, 0x6d, 0xda, 0xa9, 0x4f, 0x9e, 0x21, 0x42, 0x84, 0x15, 0x2a, 0x54,    0xa8, 0x4d, 0x9a, 0x29, 0x52, 0xa4, 0x55, 0xaa, 0x49, 0x92, 0x39, 0x72, 0xe4, 0xd5, 0xb7, 0x73,    0xe6, 0xd1, 0xbf, 0x63, 0xc6, 0x91, 0x3f, 0x7e, 0xfc, 0xe5, 0xd7, 0xb3, 0x7b, 0xf6, 0xf1, 0xff,    0xe3, 0xdb, 0xab, 0x4b, 0x96, 0x31, 0x62, 0xc4, 0x95, 0x37, 0x6e, 0xdc, 0xa5, 0x57, 0xae, 0x41,    0x82, 0x19, 0x32, 0x64, 0xc8, 0x8d, 0x07, 0x0e, 0x1c, 0x38, 0x70, 0xe0, 0xdd, 0xa7, 0x53, 0xa6,    0x51, 0xa2, 0x59, 0xb2, 0x79, 0xf2, 0xf9, 0xef, 0xc3, 0x9b, 0x2b, 0x56, 0xac, 0x45, 0x8a, 0x09,    0x12, 0x24, 0x48, 0x90, 0x3d, 0x7a, 0xf4, 0xf5, 0xf7, 0xf3, 0xfb, 0xeb, 0xcb, 0x8b, 0x0b, 0x16,    0x2c, 0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83, 0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x00  ];  // Working buffers:  // data input and ecc append, image working buffer, fixed part of image, run lengths for badness  var strinbuf = [], eccbuf = [], qrframe = [], framask = [], rlens = [];  // Control values - width is based on version, last 4 are from table.  var version, width, neccblk1, neccblk2, datablkw, eccblkwid;  var ecclevel = 2;  // set bit to indicate cell in qrframe is immutable.  symmetric around diaGonal  function setmask(x, y) {    var bt;    if (x > y) {      bt = x;      x = y;      y = bt;    }    // y*y = 1+3+5...    bt = y;    bt *= y;    bt += y;    bt >>= 1;    bt += x;    framask[bt] = 1;  }  // enter alignment pattern - black to qrframe, white to mask (later black frame merged to mask)  function putalign(x, y) {    var j;    qrframe[x + width * y] = 1;    for (j = -2; j < 2; j++) {      qrframe[(x + j) + width * (y - 2)] = 1;      qrframe[(x - 2) + width * (y + j + 1)] = 1;      qrframe[(x + 2) + width * (y + j)] = 1;      qrframe[(x + j + 1) + width * (y + 2)] = 1;    }    for (j = 0; j < 2; j++) {      setmask(x - 1, y + j);      setmask(x + 1, y - j);      setmask(x - j, y - 1);      setmask(x + j, y + 1);    }  }  //========================================================================  // Reed Solomon error correction  // exponentiation mod N  function modnn(x) {    while (x >= 255) {      x -= 255;      x = (x >> 8) + (x & 255);    }    return x;  }  var genpoly = [];  // Calculate and append ECC data to data block.  Block is in strinbuf, indexes to buffers given.  function appendrs(data, dlen, ecbuf, eclen) {    var i, j, fb;    for (i = 0; i < eclen; i++)      strinbuf[ecbuf + i] = 0;    for (i = 0; i < dlen; i++) {      fb = glog[strinbuf[data + i] ^ strinbuf[ecbuf]];      if (fb != 255)             for (j = 1; j < eclen; j++)          strinbuf[ecbuf + j - 1] = strinbuf[ecbuf + j] ^ gexp[modnn(fb + genpoly[eclen - j])];      else        for (j = ecbuf; j < ecbuf + eclen; j++)          strinbuf[j] = strinbuf[j + 1];      strinbuf[ecbuf + eclen - 1] = fb == 255 ? 0 : gexp[modnn(fb + genpoly[0])];    }  }  //========================================================================  // Frame data insert following the path rules  // check mask - since symmetrical use half.  function ismasked(x, y) {    var bt;    if (x > y) {      bt = x;      x = y;      y = bt;    }    bt = y;    bt += y * y;    bt >>= 1;    bt += x;    return framask[bt];  }  //========================================================================  //  Apply the selected mask out of the 8.  function applymask(m) {    var x, y, r3x, r3y;    switch (m) {      case 0:        for (y = 0; y < width; y++)          for (x = 0; x < width; x++)            if (!((x + y) & 1) && !ismasked(x, y))              qrframe[x + y * width] ^= 1;        break;      case 1:        for (y = 0; y < width; y++)          for (x = 0; x < width; x++)            if (!(y & 1) && !ismasked(x, y))              qrframe[x + y * width] ^= 1;        break;      case 2:        for (y = 0; y < width; y++)          for (r3x = 0, x = 0; x < width; x++ , r3x++) {            if (r3x == 3)              r3x = 0;            if (!r3x && !ismasked(x, y))              qrframe[x + y * width] ^= 1;          }        break;      case 3:        for (r3y = 0, y = 0; y < width; y++ , r3y++) {          if (r3y == 3)            r3y = 0;          for (r3x = r3y, x = 0; x < width; x++ , r3x++) {            if (r3x == 3)              r3x = 0;            if (!r3x && !ismasked(x, y))              qrframe[x + y * width] ^= 1;          }        }        break;      case 4:        for (y = 0; y < width; y++)          for (r3x = 0, r3y = ((y >> 1) & 1), x = 0; x < width; x++ , r3x++) {            if (r3x == 3) {              r3x = 0;              r3y = !r3y;            }            if (!r3y && !ismasked(x, y))              qrframe[x + y * width] ^= 1;          }        break;      case 5:        for (r3y = 0, y = 0; y < width; y++ , r3y++) {          if (r3y == 3)            r3y = 0;          for (r3x = 0, x = 0; x < width; x++ , r3x++) {            if (r3x == 3)              r3x = 0;            if (!((x & y & 1) + !(!r3x | !r3y)) && !ismasked(x, y))              qrframe[x + y * width] ^= 1;          }        }        break;      case 6:        for (r3y = 0, y = 0; y < width; y++ , r3y++) {          if (r3y == 3)            r3y = 0;          for (r3x = 0, x = 0; x < width; x++ , r3x++) {            if (r3x == 3)              r3x = 0;            if (!(((x & y & 1) + (r3x && (r3x == r3y))) & 1) && !ismasked(x, y))              qrframe[x + y * width] ^= 1;          }        }        break;      case 7:        for (r3y = 0, y = 0; y < width; y++ , r3y++) {          if (r3y == 3)            r3y = 0;          for (r3x = 0, x = 0; x < width; x++ , r3x++) {            if (r3x == 3)              r3x = 0;            if (!(((r3x && (r3x == r3y)) + ((x + y) & 1)) & 1) && !ismasked(x, y))              qrframe[x + y * width] ^= 1;          }        }        break;    }    return;  }  // Badness coefficients.  var N1 = 3, N2 = 3, N3 = 40, N4 = 10;  // Using the table of the length of each run, calculate the amount of bad image   // - long runs or those that look like finders; called twice, once each for X and Y  function badruns(length) {    var i;    var runsbad = 0;    for (i = 0; i <= length; i++)      if (rlens[i] >= 5)        runsbad += N1 + rlens[i] - 5;    // BwBBBwB as in finder    for (i = 3; i < length - 1; i += 2)      if (rlens[i - 2] == rlens[i + 2]        && rlens[i + 2] == rlens[i - 1]        && rlens[i - 1] == rlens[i + 1]        && rlens[i - 1] * 3 == rlens[i]        // white around the black pattern? Not part of spec        && (rlens[i - 3] == 0 // beginning          || i + 3 > length  // end          || rlens[i - 3] * 3 >= rlens[i] * 4 || rlens[i + 3] * 3 >= rlens[i] * 4)      )        runsbad += N3;    return runsbad;  }  // Calculate how bad the masked image is - blocks, imbalance, runs, or finders.  function badcheck() {    var x, y, h, b, b1;    var thisbad = 0;    var bw = 0;    // blocks of same color.    for (y = 0; y < width - 1; y++)      for (x = 0; x < width - 1; x++)        if ((qrframe[x + width * y] && qrframe[(x + 1) + width * y]          && qrframe[x + width * (y + 1)] && qrframe[(x + 1) + width * (y + 1)]) // all black          || !(qrframe[x + width * y] || qrframe[(x + 1) + width * y]            || qrframe[x + width * (y + 1)] || qrframe[(x + 1) + width * (y + 1)])) // all white          thisbad += N2;    // X runs    for (y = 0; y < width; y++) {      rlens[0] = 0;      for (h = b = x = 0; x < width; x++) {        if ((b1 = qrframe[x + width * y]) == b)          rlens[h]++;        else          rlens[++h] = 1;        b = b1;        bw += b ? 1 : -1;      }      thisbad += badruns(h);    }    // black/white imbalance    if (bw < 0)      bw = -bw;    var big = bw;    var count = 0;    big += big << 2;    big <<= 1;    while (big > width * width)      big -= width * width, count++;    thisbad += count * N4;    // Y runs    for (x = 0; x < width; x++) {      rlens[0] = 0;      for (h = b = y = 0; y < width; y++) {        if ((b1 = qrframe[x + width * y]) == b)          rlens[h]++;        else          rlens[++h] = 1;        b = b1;      }      thisbad += badruns(h);    }    return thisbad;  }  function genframe(instring) {    var x, y, k, t, v, i, j, m;    // find the smallest version that fits the string    t = instring.length;    version = 0;    do {      version++;      k = (ecclevel - 1) * 4 + (version - 1) * 16;      neccblk1 = eccblocks[k++];      neccblk2 = eccblocks[k++];      datablkw = eccblocks[k++];      eccblkwid = eccblocks[k];      k = datablkw * (neccblk1 + neccblk2) + neccblk2 - 3 + (version <= 9);      if (t <= k)        break;    } while (version < 40);    // FIXME - insure that it fits insted of being truncated    width = 17 + 4 * version;    // allocate, clear and setup data structures    v = datablkw + (datablkw + eccblkwid) * (neccblk1 + neccblk2) + neccblk2;    for (t = 0; t < v; t++)      eccbuf[t] = 0;    strinbuf = instring.slice(0);    for (t = 0; t < width * width; t++)      qrframe[t] = 0;    for (t = 0; t < (width * (width + 1) + 1) / 2; t++)      framask[t] = 0;    // insert finders - black to frame, white to mask    for (t = 0; t < 3; t++) {      k = 0;      y = 0;      if (t == 1)        k = (width - 7);      if (t == 2)        y = (width - 7);      qrframe[(y + 3) + width * (k + 3)] = 1;      for (x = 0; x < 6; x++) {        qrframe[(y + x) + width * k] = 1;        qrframe[y + width * (k + x + 1)] = 1;        qrframe[(y + 6) + width * (k + x)] = 1;        qrframe[(y + x + 1) + width * (k + 6)] = 1;      }      for (x = 1; x < 5; x++) {        setmask(y + x, k + 1);        setmask(y + 1, k + x + 1);        setmask(y + 5, k + x);        setmask(y + x + 1, k + 5);      }      for (x = 2; x < 4; x++) {        qrframe[(y + x) + width * (k + 2)] = 1;        qrframe[(y + 2) + width * (k + x + 1)] = 1;        qrframe[(y + 4) + width * (k + x)] = 1;        qrframe[(y + x + 1) + width * (k + 4)] = 1;      }    }    // alignment blocks    if (version > 1) {      t = adelta[version];      y = width - 7;      for (; ;) {        x = width - 7;        while (x > t - 3) {          putalign(x, y);          if (x < t)            break;          x -= t;        }        if (y <= t + 9)          break;        y -= t;        putalign(6, y);        putalign(y, 6);      }    }    // single black    qrframe[8 + width * (width - 8)] = 1;    // timing gap - mask only    for (y = 0; y < 7; y++) {      setmask(7, y);      setmask(width - 8, y);      setmask(7, y + width - 7);    }    for (x = 0; x < 8; x++) {      setmask(x, 7);      setmask(x + width - 8, 7);      setmask(x, width - 8);    }    // reserve mask-format area    for (x = 0; x < 9; x++)      setmask(x, 8);    for (x = 0; x < 8; x++) {      setmask(x + width - 8, 8);      setmask(8, x);    }    for (y = 0; y < 7; y++)      setmask(8, y + width - 7);    // timing row/col    for (x = 0; x < width - 14; x++)      if (x & 1) {        setmask(8 + x, 6);        setmask(6, 8 + x);      }      else {        qrframe[(8 + x) + width * 6] = 1;        qrframe[6 + width * (8 + x)] = 1;      }    // version block    if (version > 6) {      t = vpat[version - 7];      k = 17;      for (x = 0; x < 6; x++)        for (y = 0; y < 3; y++ , k--)          if (1 & (k > 11 ? version >> (k - 12) : t >> k)) {            qrframe[(5 - x) + width * (2 - y + width - 11)] = 1;            qrframe[(2 - y + width - 11) + width * (5 - x)] = 1;          }          else {            setmask(5 - x, 2 - y + width - 11);            setmask(2 - y + width - 11, 5 - x);          }    }    // sync mask bits - only set above for white spaces, so add in black bits    for (y = 0; y < width; y++)      for (x = 0; x <= y; x++)        if (qrframe[x + width * y])          setmask(x, y);    // convert string to bitstream    // 8 bit data to QR-coded 8 bit data (numeric or alphanum, or kanji not supported)    v = strinbuf.length;    // string to array    for (i = 0; i < v; i++)      eccbuf[i] = strinbuf.charCodeAt(i);    strinbuf = eccbuf.slice(0);    // calculate max string length    x = datablkw * (neccblk1 + neccblk2) + neccblk2;    if (v >= x - 2) {      v = x - 2;      if (version > 9)        v--;    }    // shift and repack to insert length prefix    i = v;    if (version > 9) {      strinbuf[i + 2] = 0;      strinbuf[i + 3] = 0;      while (i--) {        t = strinbuf[i];        strinbuf[i + 3] |= 255 & (t << 4);        strinbuf[i + 2] = t >> 4;      }      strinbuf[2] |= 255 & (v << 4);      strinbuf[1] = v >> 4;      strinbuf[0] = 0x40 | (v >> 12);    }    else {      strinbuf[i + 1] = 0;      strinbuf[i + 2] = 0;      while (i--) {        t = strinbuf[i];        strinbuf[i + 2] |= 255 & (t << 4);        strinbuf[i + 1] = t >> 4;      }      strinbuf[1] |= 255 & (v << 4);      strinbuf[0] = 0x40 | (v >> 4);    }    // fill to end with pad pattern    i = v + 3 - (version < 10);    while (i < x) {      strinbuf[i++] = 0xec;      // buffer has room    if (i == x)      break;      strinbuf[i++] = 0x11;    }    // calculate and append ECC    // calculate generator polynomial    genpoly[0] = 1;    for (i = 0; i < eccblkwid; i++) {      genpoly[i + 1] = 1;      for (j = i; j > 0; j--)        genpoly[j] = genpoly[j]          ? genpoly[j - 1] ^ gexp[modnn(glog[genpoly[j]] + i)] : genpoly[j - 1];      genpoly[0] = gexp[modnn(glog[genpoly[0]] + i)];    }    for (i = 0; i <= eccblkwid; i++)      genpoly[i] = glog[genpoly[i]]; // use logs for genpoly[] to save calc step    // append ecc to data buffer    k = x;    y = 0;    for (i = 0; i < neccblk1; i++) {      appendrs(y, datablkw, k, eccblkwid);      y += datablkw;      k += eccblkwid;    }    for (i = 0; i < neccblk2; i++) {      appendrs(y, datablkw + 1, k, eccblkwid);      y += datablkw + 1;      k += eccblkwid;    }    // interleave blocks    y = 0;    for (i = 0; i < datablkw; i++) {      for (j = 0; j < neccblk1; j++)        eccbuf[y++] = strinbuf[i + j * datablkw];      for (j = 0; j < neccblk2; j++)        eccbuf[y++] = strinbuf[(neccblk1 * datablkw) + i + (j * (datablkw + 1))];    }    for (j = 0; j < neccblk2; j++)      eccbuf[y++] = strinbuf[(neccblk1 * datablkw) + i + (j * (datablkw + 1))];    for (i = 0; i < eccblkwid; i++)      for (j = 0; j < neccblk1 + neccblk2; j++)        eccbuf[y++] = strinbuf[x + i + j * eccblkwid];    strinbuf = eccbuf;    // pack bits into frame avoiding masked area.    x = y = width - 1;    k = v = 1;         // up, minus        m = (datablkw + eccblkwid) * (neccblk1 + neccblk2) + neccblk2;    for (i = 0; i < m; i++) {      t = strinbuf[i];      for (j = 0; j < 8; j++ , t <<= 1) {        if (0x80 & t)          qrframe[x + width * y] = 1;        do {        // find next fill position          if (v)            x--;          else {            x++;            if (k) {              if (y != 0)                y--;              else {                x -= 2;                k = !k;                if (x == 6) {                  x--;                  y = 9;                }              }            }            else {              if (y != width - 1)                y++;              else {                x -= 2;                k = !k;                if (x == 6) {                  x--;                  y -= 8;                }              }            }          }          v = !v;        } while (ismasked(x, y));      }    }    // save pre-mask copy of frame    strinbuf = qrframe.slice(0);    t = 0;           // best    y = 30000;         // demerit    // for instead of while since in original arduino code    // if an early mask was "good enough" it wouldn't try for a better one    // since they get more complex and take longer.    for (k = 0; k < 8; k++) {      applymask(k);      // returns black-white imbalance      x = badcheck();      if (x < y) { // current mask better than previous best?        y = x;        t = k;      }      if (t == 7)        break;       // don't increment i to a void redoing mask      qrframe = strinbuf.slice(0); // reset for next pass    }    if (t != k)         // redo best mask - none good enough, last wasn't t      applymask(t);    // add in final mask/ecclevel bytes    y = fmtword[t + ((ecclevel - 1) << 3)];    // low byte    for (k = 0; k < 8; k++ , y >>= 1)      if (y & 1) {        qrframe[(width - 1 - k) + width * 8] = 1;        if (k < 6)          qrframe[8 + width * k] = 1;        else          qrframe[8 + width * (k + 1)] = 1;      }    // high byte    for (k = 0; k < 7; k++ , y >>= 1)      if (y & 1) {        qrframe[8 + width * (width - 7 + k)] = 1;        if (k)          qrframe[(6 - k) + width * 8] = 1;        else          qrframe[7 + width * 8] = 1;      }    return qrframe;  }  var _canvas = null;  var api = {    get ecclevel() {      return ecclevel;    },    set ecclevel(val) {      ecclevel = val;    },    get size() {      return _size;    },    set size(val) {      _size = val    },    get canvas() {      return _canvas;    },    set canvas(el) {      _canvas = el;    },    getFrame: function (string) {      return genframe(string);    },    //这里的utf16to8(str)是对Text中的字符串进行转码，让其支持中文    utf16to8: function (str) {      var out, i, len, c;      out = "";      len = str.length;      for (i = 0; i < len; i++) {        c = str.charCodeAt(i);        if ((c >= 0x0001) && (c <= 0x007F)) {          out += str.charAt(i);        } else if (c > 0x07FF) {          out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));          out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));          out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));        } else {          out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));          out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));        }      }      return out;    },         draw: function (str, canvas, cavW, cavH, $this, ecc) {      var that = this;      ecclevel = ecc || ecclevel;      canvas = canvas || _canvas;      if (!canvas) {        console.warn('No canvas provided to draw QR code in!')        return;      }      var size = Math.min(cavW, cavH);      str = that.utf16to8(str);//增加中文显示      var frame = that.getFrame(str),        // 组件中生成qrcode需要绑定this         ctx = wx.createCanvasContext(canvas,$this),        px = Math.round(size / (width + 8));      var roundedSize = px * (width + 8),        offset = Math.floor((size - roundedSize) / 2);      size = roundedSize;      //ctx.clearRect(0, 0, cavW, cavW);      ctx.setFillStyle('#ffffff')      ctx.fillRect(0, 0, cavW, cavW);      ctx.setFillStyle('#000000');      for (var i = 0; i < width; i++) {        for (var j = 0; j < width; j++) {          if (frame[j * width + i]) {            ctx.fillRect(px * (4 + i) + offset, px * (4 + j) + offset, px, px);          }        }      }      ctx.draw();    }  }  module.exports = { api }  // exports.draw = api;})();

来源地址：https://blog.csdn.net/weixin_42322886/article/details/128974862