动态创建SpiteFrame

let spriteFrame = new SpriteFrame();
if (!this.renderTexture) {
      let renderTexture = this.renderTexture = new RenderTexture();
      let frameSize = view.getVisibleSize();
      renderTexture.resize(frameSize.width, frameSize.height!);
 }
camera.enabled = true;
//获取摄像机的内容
camera.targetTexture = this.renderTexture;

spriteFrame._textureSource = camera.targetTexture;
this.sprite && (this.sprite.spriteFrame = spriteFrame);