호랑이 해를 맞아 아바타 프레임을 만들기 위한 작은 프로그램을 단계별로 구현해 보세요(연습)

<button bindtap="getUserProfile" class="btn1">获取头像</button>

    // 推荐使用wx.getUserProfile获取用户信息，开发者每次通过该接口获取用户个人信息均需用户确认
    getUserProfile(e) {
      let that = this;
      wx.getUserProfile({
          desc: '仅用于生成头像使用', // 声明获取用户个人信息后的用途，后续会展示在弹窗中，请谨慎填写
          success: (res) => {
            //获取高清用户头像
            let url = res.userInfo.avatarUrl;
            while (!isNaN(parseInt(url.substring(url.length - 1, url.length)))) {
              url = url.substring(0, url.length - 1)
            }
            url = url.substring(0, url.length - 1) + "/0";
            res.userInfo.avatarUrl = url;
            that.setData({
              userInfo: res.userInfo,
              hasUserInfo: true
            })
          }
        });
    },

drawImg(){
      wx.showLoading({
        title: '生成头像中...',
      })
      let that = this;
      let type = this.data.hotArr[this.data.curHot].key;
      let promise1 = new Promise(function(resolve, reject) {
        wx.getImageInfo({
          src: that.data.userInfo.avatarUrl,
          success: function(res) {
            resolve(res);
          }
        })
      });
      var index = that.data.defaultImg;
      let promise2 = new Promise(function(resolve, reject) {
        wx.getImageInfo({
          src: `../../images/${type}/hat${index}.png`,
          success: function(res) {
            resolve(res);
          }
        })
      });
      Promise.all([
        promise1, promise2
      ]).then(res => {
        //主要就是计算好各个图文的位置
        pc.clearRect(0, 0, windowWidth, size);
        //绘制背景图
        pc.drawImage(res[0].path, windowWidth/2-130, 0, size, size)
        //绘制相框图
        pc.drawImage('../../' + res[1].path, windowWidth/2-130, 0, size, size)
        pc.stroke()
        pc.draw(false, () => {
            //图片绘制成功回调,调用保存canvas方法
            this.canvasToTempFile();
        })
      })
    },

 canvasToTempFile(){
    wx.canvasToTempFilePath({
      x: windowWidth/2-130,  //这个地方减去130是因为我们的图片尺寸设置的是260
      y: 0,
      height: size,
      width: size,
      canvasId: 'myCanvas',
      success: (res) => {
        wx.saveImageToPhotosAlbum({
          filePath: res.tempFilePath,
          success: result => {
            wx.hideLoading();
            wx.showModal({
              content: '图片已保存到相册,请前往微信去设置哟!',
              showCancel: false,
              success: function(res) {
                if (res.confirm) {
                  console.log('用户点击确定');
                }
              }
            })
          }, fail(e) {
            wx.hideLoading();
            console.log("err:" + e);
          }
        })
      }
    });
  },