wx.authorize({
    scope: 'scope.writePhotosAlbum',
    success() {
        // 授權成功
        wx.saveImageToPhotosAlbum({
            filePath: that.data.tempFilePath,
            success() {
                app.func.setMask({
                    message: '圖片保存成功',
                    bg: 'success'
                }, that)
                return
            }
        })
    },
    fail:function(){
        // 授權失敗
        wx.showModal({
            title: '警告',
            content: '您點擊了拒絕授權,將無法正常保存圖片,點擊確定重新獲取授權。',
            success: function (res) {
                if (res.confirm) {
                    wx.openSetting({
                        success: (res) => {
                            console.log('授權成功')
                        }
                    })
                }
            }
        })
    }
})

判斷權限和結果的兩個函數

    //判斷圖片權限
  isAuth: function (res) {
    let that = this;
    wx.getSetting({
      success(res) {
        if (!res.authSetting['scope.writePhotosAlbum']) {
          wx.authorize({
            scope: 'scope.writePhotosAlbum',
            success(res) {
            }
          })
        } else {
          that.setData({ isSaveImageToPhotosAlbum: true })
        }
      },
    })
  },
  //判斷授權結果
  authOpen: function (res) {
    let that = this;
    if (res.detail.authSetting['scope.writePhotosAlbum']) {
      that.setData({ isSaveImageToPhotosAlbum: true })
    } else {
      that.setData({ isSaveImageToPhotosAlbum: false })
    }
  },