后台接口

/// <summary>
/// 获取二维码
/// </summary>
/// <returns></returns>
[HttpPost]
[Authorize]
public async Task<MessageModel<string>> GetUserQRCode()
{var result = new MessageModel<string>();var url = "pages/index/index";var scene = $"aa=111";var res = await weChatMiniProgramHelper.GetUnlimitedQRCode(url, scene, "trial");//封装的获取二维码地址//https://developers.weixin.qq.com/miniprogram/dev/OpenApiDoc/qrcode-link/qr-code/getUnlimitedQRCode.htmlif (!res.isSuccess){result.Success = false;result.Msg = Encoding.UTF8.GetString(res.img);//失败了返回错误信息return result;}result.Success = true;result.Msg = "成功";result.Response = Convert.ToBase64String(res.img);return result;
}

小程序

数据

data: {imgData: '',
},

获取base64的数据

/*** 获取专属推广码*/
getUserQRCode() {postRequestWithToken("/GetQRCode", {}, (data) => {if (data.data.success) {this.setData({imgData: data.data.response})} else {wx.showToast({title: data.data.msg,icon: 'error'})}}, (err) => {wx.showToast({title: "网络繁忙，请重试",icon: 'error'})}, true, () => {});
},

展示

<image bindlongpress="showSave" src="data:image/PNG;base64,{{imgData}}" />

处理长按事件

/*** 保存base64的图片* @param {String} imgData*/
function saveBase64Img(imgData) {let save = wx.getFileSystemManager();let number = Math.random();save.writeFile({filePath: wx.env.USER_DATA_PATH + '/pic' + number + '.png',data: imgData,encoding: 'base64',success: (res) => {wx.saveImageToPhotosAlbum({filePath: wx.env.USER_DATA_PATH + '/pic' + number + '.png',success: function (res) {showNoIconToast("保存成功");},fail: function (err) {showNoIconToast("保存失败");}});},fail: (err) => {showNoIconToast("保存失败");}})
}/*** 长按保存*/showSave() {let that = this;wx.showActionSheet({itemList: ['保存'],success(res) {switch (res.tapIndex) {case 0://实现保存saveBase64Img(that.data.imgData);break;}},fail(res) {if (res.errMsg != "showActionSheet:fail cancel") {wx.showToast({title: '保存失败',icon: 'error'})}}})}