Canvas2D，根据像素比使用scale缩放后，用wx.canvasToTempFilePath生成图片，在PC端会导致生成的图片不完整。请管理员大大指教！

canvas.width = canvasWidth*this.data.dpr

canvas.height = canvasHeight*this.data.dpr

ctx.scale(this.data.dpr, this.data.dpr) // 根据像素比放大

1.开发工具和手机端正确：能完整生成全图。

2.PC端同样代码，无法生成完整全图。

代码片段：https://developers.weixin.qq.com/s/IW9zr9mJ73Pj

主要代码：

const app = getApp()
const sysInfo = wx.getSystemInfoSync() // 获取设备信息

Page({
  data: {
    dpr: sysInfo.pixelRatio,
    canvasWidth: 750,
    canvasHeight: 421.875, // 默认16:9
    fileCoverHttpUrl: 'https://jszs.ds.net.cn/api/file7/ccw/temp/2023-07-24/1522147391/3e22c349259b2d9000b8d7c2d93d7314.mp4?ss=0.1',
  },
  onLoad() {
   
  },
  handleDraw() {
    const {fileCoverHttpUrl} = this.data;
    let imagePath = '';
    this.createCanvas().then(async () => {
      const coverImageInfo = await wx.getImageInfo({
        src: fileCoverHttpUrl,
      })
      const {path, width, height} = coverImageInfo;
      imagePath = path; // 临时路径 
      this.loadImg(imagePath).then(img => {
        this.drawMedia(img);
      })
    });
  },
  drawMedia(media) {
    const {canvas, ctx} = this;
    const {canvasWidth, canvasHeight} = this.data;
    console.log('drawMedia', canvasWidth, canvasHeight);
    canvas.width = canvasWidth*this.data.dpr
    canvas.height = canvasHeight*this.data.dpr
    ctx.scale(this.data.dpr, this.data.dpr) // 根据像素比放大
    ctx.drawImage(media, 0, 0, canvasWidth, canvasHeight);
    // 延时生成图片 
    setTimeout(() => {
      wx.canvasToTempFilePath({
        canvas: canvas,
        x: 0,
        y: 0,
        width: canvasWidth*this.data.dpr,
        height: canvasHeight*this.data.dpr,
        destWidth: canvasWidth, // 输出的图片的宽度 
        destHeight: canvasHeight,
        success: res => {
          wx.hideLoading();
          this.setData({
            showPoster: true,
            tempShareImg: res.tempFilePath,
          });
        },
        fail: () => {
          wx.showToast({
            title: '图片生成失败~',
            icon: 'none'
          });
        }
      })
    }, 300)
  },
  
  createCanvas() {
    
    return new Promise(resolve => {
      wx.createSelectorQuery()
      .select('#canvas')
      .fields({ node: true, size: true })
      .exec((res) => {
        const {canvasWidth, canvasHeight} = this.data;
        const canvas = res[0].node;
        const ctx = canvas.getContext('2d');
        canvas.width = canvasWidth;
        canvas.height = canvasHeight;
        ctx.clearRect(0, 0, canvasWidth, canvasHeight)
        this.canvas = canvas;
        this.ctx = ctx;
        resolve();
      })
    })


  },
  loadImg(src){
    return new Promise((resolve, reject) => {
      const {canvas} = this;
      const image = canvas.createImage()
      image.src = src
      image.onload = () => {
        resolve(image)
      }
      image.onerror = () => {
        reject(new Error(`fail to fetch image form: ${src}`))
      }
    })
  },
   
})