Page({
  onReady: function () {
    wx.createSelectorQuery().select("#myCanvas").fields({
      node: true,
      size: true
    }).exec((res) => {
      const canvas = res[0].node;
      this.canvas = canvas
      this.ctx = canvas.getContext("2d")
    });
    this.drawCamera()
  },
  drawCamera: function () {
    const camera = wx.createCameraContext()
    this.count = 0
    const cameraListener = camera.onCameraFrame((frame) => {
      if (this.count < 10) console.log(frame)
      this.count++
      this.canvas.width = frame.width
      this.canvas.height = frame.height
      let data = new Uint8Array(frame.data);
      let clamped = new Uint8ClampedArray(data);
      let imageData = this.canvas.createImageData(clamped, frame.width, frame.height);
      this.ctx.putImageData(imageData, 0, 0, 0, 0, frame.width, frame.height);
    })
    cameraListener.start()
  }
})

谢谢