https://developers.weixin.qq.com/miniprogram/dev/component/canvas.html   toggleScreenShotMode() {     console.log("点击截屏")     const videoContext = wx.createVideoContext('ulVideo', this);     const query = wx.createSelectorQuery();     query.select('#videoCanvas')       .fields({         node: true,         size: true       })       .exec((res) => {         console.log(res);         const canvas = res[0].node;         const canvasContext = canvas.getContext('2d');         const width = res[0].width;         const height = res[0].height;         canvas.width = width;         canvas.height = height;         videoContext.pause();            console.log('currentTime =', this.data.currentTime);         videoContext.seek(this.data.currentTime);         setTimeout(() => {           wx.createSelectorQuery().select('#ulVideo').context().exec((res) => {             console.log(res);             const video = res[0].context;             canvasContext.clearRect(0, 0, width, height);             canvasContext.drawImage(video, 0, 0, width, height);                wx.canvasToTempFilePath({               canvas: canvas,               fileType: 'jpg',               success: (res) => {                 console.log('截屏成功', res.tempFilePath);                 // 获取图像数据                 wx.getFileSystemManager().readFile({                   filePath: res.tempFilePath,                   encoding: 'base64',                   success: (fileRes) => {                     const base64Image = 'data:image/png;base64,' + fileRes.data;                     this.addImageToReport(res.tempFilePath, base64Image);                   },                   fail: (err) => {                     console.error('读取图像数据失败：', err);                   },                 });               },               fail: (err) => {                 console.error('截屏失败', err);               }             });           });         }, 500);       });   },