IEnumerator CaptureScreenshot()
    {
        //只在每一帧渲染完成后才读取屏幕信息
        yield return new WaitForEndOfFrame();

        Texture2D m_texture = new Texture2D(Screen.width, Screen.height, TextureFormat.RGB24, false);
        // 读取Rect范围内的像素并存入纹理中
        m_texture.ReadPixels(new Rect(0, 0, Screen.width, Screen.height), 0, 0);
        // 实际应用纹理
        m_texture.Apply();

        Color color = m_texture.GetPixel((int)Input.mousePosition.x, (int)Input.mousePosition.y);

}