PhonicsGame_master/pages/main/print.js

import common from '../../utils/util';
import server from '../../utils/main';

const app = getApp()
Page({
  data: {
    Left: 0,
  },
  onLoad: function(options) {
    var id = options.id;
    id = 179;
    this.getList(id);
  },
  getList: function(id) {
    var that = this;

    server.getLocalHost(function() {
      server.getData('GetQuestionTypesPrint?ID=' + id, function(data) {
        //console.log("UserInfo:" + data);
        if (data) {
          that.saveImage(data);
        }
      });

    });
  },
  saveImage: function(item) {
    var that = this;
    var ctx = wx.createCanvasContext("Canvas", that);
    ctx.setFillStyle('white');
    ctx.fillRect(0, 0, 1050, 1485);
    ctx.setTextAlign('left');
    ctx.setTextBaseline('top');
    ctx.fillStyle = "#000000";
    ctx.setFontSize(32);
    ctx.fillText(item.Name, 60, 45);


    ctx.setFontSize(12);
    ctx.fillText(item.CagegoryName, 60, 90);
    ctx.fillText("共" + item.QuestionList.length + "道题", 60, 125);
    ctx.fillText("第 1 / 1 页", 60, 147);
    ctx.fillText("答案检索号", 768, 60);

    ctx.setTextAlign('right');
    ctx.fillText("出题时间 " + item.CreateTime, 875, 94);
    ctx.fillText("微信扫一扫 计时看答案", 875, 111);
    ctx.fillText("《数学计算题》选题 打印 扫码 批改", 875, 137);
    ctx.setFontSize(32);
    ctx.fillText("99", 875, 50);
    ctx.drawImage("../../images/answer.png", 890, 54, 100, 100);

    ctx.setTextBaseline('middle');
    var xStart = 60;
    var yStart = 247;
    var index = 0;
    for (var i = 0; i < 3; i++) {
      for (var j = 0; j < 20; j++) {
        index++;
        ctx.setTextAlign('left');
        ctx.setFontSize(12);
        ctx.fillText("(", xStart + i * 310, yStart + j * 59);
        ctx.setTextAlign('center');
        ctx.fillText(index, xStart + i * 310 + 13, yStart + j * 59);
        ctx.setTextAlign('left');
        ctx.fillText(")", xStart + i * 310 + 22, yStart + j * 59);

        ctx.setFontSize(24);

        var A = item.QuestionList[index - 1].A.toString();
        if (item.QuestionList[index - 1].HiddenColumn == "A")
          A = "____";
        var OperateAB = item.QuestionList[index - 1].OperateAB.toString();
        console.log(OperateAB);
        var B = item.QuestionList[index - 1].B.toString();
        if (item.QuestionList[index - 1].HiddenColumn == "B")
          B = "____";
        var equation = A + " " + OperateAB + " " + B;
        if (item.QuestionList[index - 1].C) {
          var OperateBC = item.QuestionList[index - 1].OperateBC.toString();
          var C = item.QuestionList[index - 1].C.toString();
          equation += " " + OperateBC + " " + C;
          if (item.QuestionList[index - 1].D) {
            var OperateCD = item.QuestionList[index - 1].OperateCD.toString();
            var D = item.QuestionList[index - 1].D.toString();
            equation += " " + OperateCD + " " + D;
          }
        }
        equation += " = ";
        var R = item.QuestionList[index - 1].R.toString();
        if (item.QuestionList[index - 1].HiddenColumn == "R")
          R = "";
        equation += R;

        var num = xStart + i * 310 + 31;
        ctx.setTextAlign('center');
        for (var n = 0; n < equation.length; n++) {
          var len = getLength(equation[n]);
          num += len;
          if (equation[n] == ".") {
            ctx.fillText(equation[n], num + 3, yStart + j * 59);
          } else {
            var h=0;
            if (equation[n]=="_")
              h=8;
            ctx.fillText(equation[n], num, yStart + j * 59+h);
          }
        }
      }
    }


    ctx.draw(true, function(n) {
      wx.canvasToTempFilePath({
        x: 0,
        y: 0,
        width: 2100,
        height: 2970,
        destWidth: 2100,
        destHeight: 2970,
        canvasId: 'Canvas',
        success: function (res2) {
          console.log(res2.tempFilePath);
          wx.previewImage({
            current: res2.tempFilePath, // 当前显示图片的http链接
            urls: [res2.tempFilePath] // 需要预览的图片http链接列表
          });
        }
      })
    });

    function getLength(str) {
      switch (str) {
        case "0":
        case "1":
        case "2":
        case "3":
        case "4":
        case "5":
        case "6":
        case "7":
        case "8":
        case "9":
          return 15;
        case ".":
          return 8;
        default:
          return 12;
      }
    }

  },
  moveLeft: function() {
    this.setData({
      Left: this.data.Left + 375,
    });
  },
  moveRight: function() {
    this.setData({
      Left: this.data.Left - 375,
    });
  }
});