当第一次的时候使用wx.getSetting的时候会发现没有scope.writePhotosAlbum这个对象，所以并不知道是否授权
在这里插入图片描述

<view class="ui-share-box">    <view class="ui-thumb">        <image mode="scaleToFill" src="{{shareThumb}}"></image>    </view>    <view class="ui-button-box main-justify">        <button class="main-center cross-center"                @tap.stop="getSaveImage">            <text class="icon-share"></text>保存图片        </button>        <button class="main-center cross-center"                    open-type="share"><text class="icon-share"></text>分享给好友</button>    </view></view><view class="ui-toast-box" :class="{'is-show': isShowToast}">    <view class="ui-toast-content dir-top main-justify">        <view class="ui-content">            <view class="cell-title">温馨提示</view>            <view class="cell-content">去设置允许访问相册</view>        </view>        <button open-type="openSetting"                bindopensetting='getSetting'>确定</button>    </view></view>

data = {    isShowToast: false,    shareThumb: '', // 最后生成的分享图片}/** * 获取微信设置信息 * @private */__wxSetting() {    let self = this    // 检测设置中是否允许保存到相册中去    wx.getSetting({        success(res) {            // 第一，直接调取保存，系统会自动调取授权            if (_.isUndefined(res.authSetting['scope.writePhotosAlbum'])) {                self.__saveImage()            } else if (!res.authSetting['scope.writePhotosAlbum']){ // 不授权                self.isShowToast = true            } else { // 授权                self.__saveImage()            }            self.$apply()        }    })}/** * 保存图片 * @private */__saveImage() {    let self = this    wx.saveImageToPhotosAlbum({        filePath: self.shareThumb, // 这里是用canvas生成之后保存下来的图片地址        success(res) {            wx.showModal({                title: '温馨提示',                content: '已保存到系统相册中',                showCancel: false            })        },        fail(res) {            wx.showModal({                title: '温馨提示',                content: '保存失败',                showCancel: false            })        }    })}methods = {    /**     * 保存图片     * @private     */    getSaveImage() {        let self = this        self.__wxSetting()    },    /**     * 询问是否授权访问相册     * @private     */    getSetting(event) {        let self = this        // 对用户的设置进行判断，如果没有授权，即使用户返回到保存页面，显示的也是“去授权”按钮；同意授权之后才显示保存按钮        self.isShowToast = false        if (!event.detail.authSetting['scope.writePhotosAlbum']) {            wx.showModal({                title: '温馨提示',                content: '你关闭了访问相册的权限，无法保存，请允许访问相册',                showCancel: false            })        } else {            wx.showToast({                icon: 'success',                title: `授权成功`,                success(res) {                    self.__saveImage()                }            })        }    }}