/// <summary>/// 将 Stream 转成 byte[]/// </summary>/// <param name="stream"></param>/// <returns></returns>public static byte[] StreamToBytes(Stream stream){    byte[] bytes = new byte[stream.Length];    stream.Read(bytes, 0, bytes.Length);    // 设置当前流的位置为流的开始    stream.Seek(0, SeekOrigin.Begin);    return bytes;}

/// <summary>/// 将 byte[] 转成 Stream/// </summary>/// <param name="bytes"></param>/// <returns></returns>public static Stream BytesToStream(byte[] bytes){    Stream stream = new MemoryStream(bytes);    return stream;}

// <summary> /// 字节流转换成图片 /// </summary> /// <param name="byt">要转换的字节流</param> /// <returns>转换得到的Image对象</returns> public static Image BytToImg(byte[] byt){    try    {        MemoryStream ms = new MemoryStream(byt);        Image img = Image.FromStream(ms);        return img;    }    catch (Exception ex)    {        LogHelper.WriteError("StreamHelper.BytToImg 异常", ex);        return null;    }}

/// <summary>///  图片转换成字节流 /// </summary>/// <param name="img"></param>/// <returns></returns>public static byte[] ImageToByteArray(Image img){    ImageConverter imgconv = new ImageConverter();    byte[] b = (byte[])imgconv.ConvertTo(img, typeof(byte[]));    return b;}

/// <summary>/// 把图片Url转化成Image对象/// </summary>/// <param name="imageUrl"></param>/// <returns></returns>public static Image Url2Img(string imageUrl){    try    {        if (string.IsNullOrEmpty(imageUrl))        {            return null;        }        WebRequest webreq = WebRequest.Create(imageUrl);        WebResponse webres = webreq.GetResponse();        Stream stream = webres.GetResponseStream();        Image image;        image = Image.FromStream(stream);        stream.Close();        return image;    }    catch (Exception ex)    {        LogHelper.WriteError("StreamHelper.Url2Img 异常", ex);    }    return null;}

/// <summary>/// 把本地图片路径转成Image对象/// </summary>/// <param name="imagePath"></param>/// <returns></returns>public static Image ImagePath2Img(string imagePath){    try    {        if (string.IsNullOrEmpty(imagePath))        {            return null;        }        byte[] bytes = Image2ByteWithPath(imagePath);        Image image = BytToImg(bytes);        return image;    }    catch (Exception ex)    {        LogHelper.WriteError("StreamHelper.ImagePath2Img 异常", ex);        return null;    }}