下载图片

download img from url

/// <summary>
/// 根据指定的url下载数据
/// </summary>
/// <param name="url">url</param>
/// <returns></returns>
public byte[] DownloadImg2Bytes(string url)
{
	WebClient wc = new WebClient();
	byte[] bytes;
	try
	{
		bytes = wc.DownloadData(url);
	}
	catch (WebException ex)
	{
		LogHelper.LogError("DownloadImg2Bytes出错了：  ex:{0}", ex);
		bytes = null;
	}

	return bytes;
}

/// <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 Image BytToImg(byte[] byt)
{

	MemoryStream ms = new MemoryStream(byt);
	Image img = Image.FromStream(ms);
	ms.Close();
	return img;
}