shareShop: function(){

    let that= this

    wx.showLoading({

      title: '加載海報(bào)中...',

    });
    // 1. 請(qǐng)求后端API生成小程序碼
    app._post_form(api.getAppletQrCode, {

      shopId: that.data.shopId,

      width: 100,

      page: 'pages/shop-detail/index'

    }, function(result) {

      if(result.code==100){

        that.setData({

          dialogShow: true

        });


        let query = wx.createSelectorQuery()//創(chuàng)建節(jié)點(diǎn)查詢(xún)器 query

        let shareCanvas = {}

        query.select('#share-canvas').boundingClientRect()//這段代碼的意思是選擇Id= the - id的節(jié)點(diǎn)优构，獲取節(jié)點(diǎn)位置信息的查詢(xún)請(qǐng)求

        query.exec(function (res) {

          that.setData({

            shareCanvas: res[0]

          });

          shareCanvas = res[0];

          const ctx = wx.createCanvasContext('shareCanvas');

          let avatarUrl = that.data.shareInfo.userPhotoUrl; //頭像

          let bgImgPath = that.data.shareInfo.bgUrl; //封面大圖
          
          // 根據(jù)設(shè)計(jì)圖計(jì)算圖片寬高比列(圖片寬高為一定值)          

          let bgImgHeight = parseInt(shareCanvas.width*1.45); //封面大圖高度

          let avatarHeight = (shareCanvas.height - bgImgHeight) * 0.7;

          let codeHeight = (shareCanvas.height - bgImgHeight) * 0.8;

          let avatarTop = parseInt(((shareCanvas.height - bgImgHeight - avatarHeight) * 0.5) + bgImgHeight);

          let codeTop = parseInt(((shareCanvas.height - bgImgHeight - codeHeight) * 0.5) + bgImgHeight);

          let firstX = avatarHeight + 30;

          //填充背景（圖片的白色背景）

          ctx.setFillStyle('#ffffff');

          ctx.fillRect(0, 0, shareCanvas.width, shareCanvas.height);//坐標(biāo)和寬高

          // 第一張圖片（封面大圖）

          // wx.getImageInfo使用：
          
          // 圖片服務(wù)器的域名加到downloadFile 合法域名

          // 圖片需要https安全域名下網(wǎng)址

          wx.getImageInfo({

            src: bgImgPath,

            success: function (bgRes) {

              ctx.drawImage(bgRes.path, 0, 0, shareCanvas.width, bgImgHeight);

              // 繪制標(biāo)題

              ctx.setFontSize(22/that.data.ratio);

              ctx.setFillStyle('#000000');

              ctx.fillText(that.data.shareInfo.desc_first, firstX, avatarTop + 24/that.data.ratio );

              // 繪制內(nèi)容

              ctx.setFontSize(22/that.data.ratio);

              ctx.setFillStyle('#000000');

              ctx.fillText(that.data.shareInfo.desc_second, firstX, avatarTop + 50/that.data.ratio);

              ctx.stroke()

              // 繪制二維碼文字

              // ctx.setFontSize(16/that.data.ratio);

              // ctx.setFillStyle('#000000');

              // ctx.fillText('長(zhǎng)按掃碼查看', shareCanvas.width - ctx.measureText('長(zhǎng)按掃碼查看').width - 15, shareCanvas.height - 5);

              ctx.save();

              ctx.beginPath();

              // 第二張圖片（花園 頭像）

              ctx.arc(avatarHeight*0.5 + 15, avatarTop + avatarHeight*0.5, avatarHeight*0.5, 0, Math.PI * 2, false);

              ctx.clip();

              wx.getImageInfo({

                src: avatarUrl,

                success: function (avatar) {

                  ctx.drawImage(avatar.path, 15, avatarTop, avatarHeight, avatarHeight);

                  ctx.restore();

                  // 繪制二維碼getImageInfo不支持顯示base64編碼的圖片
                  // base64src為外部處理base64編碼并在本地臨時(shí)生成一張圖片的方法

                  base64src(result.result, base64srcres => {

                    ctx.drawImage(base64srcres, shareCanvas.width - avatarHeight - 15, codeTop, codeHeight, codeHeight);

                    ctx.draw();

                    wx.hideLoading();

                  });

                }

              });

            }

          });

        });

      }else{

        app.showError('網(wǎng)絡(luò)出小差了,請(qǐng)稍后重試...');

      }

    })

  }