微信小程序點擊按鈕將圖片保存到手機

 SaveCard: function(e) {
    let that = this;
    console.log('保存');
    var imgSrc = e.currentTarget.dataset.img;
    //獲取相冊授權
    wx.getSetting({
      success(res) {
        if (!res.authSetting['scope.writePhotosAlbum']) {
          wx.authorize({
            scope: 'scope.writePhotosAlbum',
            success() {
              console.log('授權成功');
              that.img(imgSrc)
            }
          })
        }else{
          that.img(imgSrc)
        }
      }
    })
  },
img: function (imgSrc){
    var imgSrc = imgSrc;
    wx.downloadFile({
      url: imgSrc,
      success: function (res) {
        console.log(res); //圖片保存到本地
        wx.saveImageToPhotosAlbum({
          filePath: res.tempFilePath,
          success: function (data) {
            console.log(data);
            wx.showToast({
              title: '保存成功',
              duration: 2000
            })
          },
          fail: function (err) {
            console.log(err);
            if (err.errMsg === "saveImageToPhotosAlbum:fail auth deny") {
              wx.openSetting({
                success(settingdata) {
                  console.log(settingdata)
                  if (settingdata.authSetting['scope.writePhotosAlbum']) {
                    wx.showToast({
                      title: '圖片已保存',
                      icon:'none',
                      duration:2000
                    })
                    console.log('獲取權限成功，給出再次點擊圖片保存到相冊的提示。')
                  } else {
                    console.log('獲取權限失敗，給出不給權限就無法正常使用的提示')
                  }
                }
              })
            }
          }
        })
      }
    })

  },

先授權，再保存