C#根据http和ftp图片地址获取对应图片

本文实例为大家分享了C#根据http和ftp地址获取对应图片的具体代码，供大家参考，具体内容如下

public class GetBitmapImageClass
{
 public BitmapSource GetImageHttp(string url,int width)
 {
  var image = new BitmapImage();
  int BytesToRead = 100;
  if (!string.IsNullOrEmpty(url))
  {
   WebRequest request = WebRequest.Create(new Uri(url, UriKind.Absolute));
   request.Timeout = -1;
   WebResponse response = request.GetResponse();
   Stream responseStream = response.GetResponseStream();
   BinaryReader reader = new BinaryReader(responseStream);
   MemoryStream memoryStream = new MemoryStream();

byte[] bytebuffer = new byte[BytesToRead];
   int bytesRead = reader.Read(bytebuffer, 0, BytesToRead);

while (bytesRead > 0)
   {
    memoryStream.Write(bytebuffer, 0, bytesRead);
    bytesRead = reader.Read(bytebuffer, 0, BytesToRead);
   }

image.BeginInit();
   image.DecodePixelWidth = width;
   image.CacheOption = BitmapCacheOption.OnLoad;
   memoryStream.Seek(0, SeekOrigin.Begin);

image.StreamSource = memoryStream;
   image.EndInit();
   image.Freeze();
   memoryStream.Close();
   reader.Close();
   responseStream.Close();
   response.Close();
  }
  return image;
 }

public BitmapSource GetImageFtp(string url, int width)
 {
  var image = new BitmapImage();
  if (!string.IsNullOrEmpty(url))
  {
   FtpWebRequest reqFtp;
   reqFtp = (FtpWebRequest)FtpWebRequest.Create(new Uri(url));

reqFtp.Method = WebRequestMethods.Ftp.DownloadFile;
   reqFtp.UseBinary = true;
   FtpWebResponse response = (FtpWebResponse)reqFtp.GetResponse();
   Stream ftpStream = response.GetResponseStream();
   MemoryStream mStream = new MemoryStream();
   ftpStream.CopyTo(mStream);
   mStream.Position = 0;
   int length = (int)mStream.Length;
   byte[] returnbyte = new byte[length];
   mStream.Read(returnbyte, 0, length);

mStream.Close();
   ftpStream.Close();
   response.Close();

System.IO.MemoryStream stream = new System.IO.MemoryStream(returnbyte);
   image.BeginInit();
   image.DecodePixelWidth = width;
   image.CacheOption = BitmapCacheOption.OnLoad;
   stream.Seek(0, SeekOrigin.Begin);

image.StreamSource = stream;
   image.EndInit();
   image.Freeze();
   stream.Close();
  }
  return image;

}

[DllImport("gdi32.dll", SetLastError = true)]
 private static extern bool DeleteObject(IntPtr hObject);

public BitmapSource ToBitmapSource(System.Drawing.Bitmap bmp)
 {
  try
  {
   var ptr = bmp.GetHbitmap();
   var source = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
    ptr, IntPtr.Zero, Int32Rect.Empty, System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());
   DeleteObject(ptr);
   return source;
  }
  catch
  {
   return null;
  }
 }

//获取缩略图
 public BitmapSource GetBitImage(string imageLink)
 {
  //"http://172.17.1.231:8083/3050273262379466760/2017/05/28/09/340800100999/09163448402.jpg?fid=1267520"
  if (imageLink.StartsWith("http://"))
  {
   return GetImageHttp(imageLink,200);
  }
  //ftp格式的
  else if (imageLink.StartsWith("ftp://"))
  {
   return GetImageFtp(imageLink, 200);
  }
 }

//获取原图
 public BitmapSource GetHightBitImage(string imageLink)
 {
  //"http://172.17.1.231:8083/3050273262379466760/2017/05/28/09/340800100999/09163448402.jpg?fid=1267520"
  if (imageLink.StartsWith("http://"))
  {
   return GetImageHttp(imageLink, 0);
  }
  //ftp格式的
  else if (imageLink.StartsWith("ftp://"))
  {
   return GetImageFtp(imageLink, 0);
  }
 }

}