從URL獲取圖片，但未完全加載

我試圖從URL獲取圖片，但是當我將其保存到文件時，它是實際圖片的一半！我搜索了許多網站和解決方案，如HttpWebRequest.BeginGetResponse，因爲我認爲這是因爲我必須緩衝數據，但它不起作用。我不知道這是我的代碼部分是錯誤的，使這個問題:(從URL獲取圖片，但未完全加載

這是從URL獲取圖像的代碼：

public static Bitmap GetImageFromUrl(string url) 
    { 
     string RefererUrl = string.Empty; 
     int TimeoutMs = 22 * 1000; 
     string requestAccept = "*/*"; 
     string UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7"; 

     Bitmap img = null; 
     HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); 

     request.UserAgent = UserAgent; 
     request.Timeout = TimeoutMs; 
     request.ReadWriteTimeout = TimeoutMs * 6; 
     request.Accept = requestAccept; 

     if (!string.IsNullOrEmpty(RefererUrl)) 
     { 
      request.Referer = RefererUrl; 
     } 

     try 
     { 
      WebResponse wResponse = request.GetResponse(); 
      using (HttpWebResponse response = wResponse as HttpWebResponse) 
      { 
       Stream responseStream = response.GetResponseStream(); 
       img = new Bitmap(responseStream); 
       response.Close(); 
      } 
     } 
     catch (Exception) 
     { 
     } 
     return img; 
    }

這這在文件中保存的圖像的代碼：

 byte[] imgBytes = tile.Image; 
     using (MemoryStream ms = new MemoryStream(imgBytes)) 
     { 
      using (Image img = Image.FromStream(ms)) 
      { 
       ms.Dispose(); 
       Bitmap tempBmp = new Bitmap(img); 
       img.Dispose(); 

       string activeDir = Environment.CurrentDirectory; 
       string newPath = System.IO.Path.Combine(activeDir, "Images"); 
       System.IO.Directory.CreateDirectory(newPath); 

       newPath = System.IO.Path.Combine(newPath, tile.TileType.ToString()); 
       System.IO.Directory.CreateDirectory(newPath); 

       newPath = System.IO.Path.Combine(newPath, tile.Zoom.ToString()); 
       System.IO.Directory.CreateDirectory(newPath); 

       newPath = System.IO.Path.Combine(newPath, tile.X.ToString()); 
       System.IO.Directory.CreateDirectory(newPath); 

       newPath = System.IO.Path.Combine(newPath, tile.Y.ToString()); 
       System.IO.Directory.CreateDirectory(newPath); 

       string newFileName = "tile.png"; 
       newPath = System.IO.Path.Combine(newPath, newFileName); 

       tempBmp.Save(newPath, ImageFormat.Png); 
       tempBmp.Dispose();

來源

2012-02-27 Arash

你的代碼看起來過於複雜，你真的需要閱讀的圖像，然後重新保存爲什麼你就不能直接保存下載的圖像，是這樣的：

 public static void GetImageFromUrl(string url) 
    { 
     string RefererUrl = string.Empty; 
     int TimeoutMs = 22 * 1000; 
     string requestAccept = "*/*"; 
     string UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7"; 

     // Bitmap img = null; 
     HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); 

     request.UserAgent = UserAgent; 
     request.Timeout = TimeoutMs; 
     request.ReadWriteTimeout = TimeoutMs * 6; 
     request.Accept = requestAccept; 

     if (!string.IsNullOrEmpty(RefererUrl)) 
     { 
      request.Referer = RefererUrl; 
     } 

     try 
     { 
      WebResponse wResponse = request.GetResponse(); 
      using (HttpWebResponse response = wResponse as HttpWebResponse) 
      { 
       Stream responseStream = response.GetResponseStream(); 
       BinaryReader br = new BinaryReader(responseStream); 

       FileStream fs = new FileStream(@"c:\pst\1.jpg", FileMode.Create, FileAccess.Write); 

       const int buffsize = 1024; 
       byte[] bytes = new byte[buffsize]; 
       int totalread = 0; 

       int numread = buffsize; 
       while (numread != 0) 
       { 
        // read from source 
        numread = br.Read(bytes, 0, buffsize); 
        totalread += numread; 

        // write to disk 
        fs.Write(bytes, 0, numread); 
       } 

       br.Close(); 
       fs.Close(); 


       response.Close(); 
      } 
     } 
     catch (Exception) 
     { 
     } 
    }

當然你應該把它分成方法，並設置適當的返回值

來源

2012-02-27 09:01:46

它工作。非常感謝你。我不知道爲什麼我的代碼無法正常工作。 – Arash 2012-02-27 09:06:14

除了代碼中的某處出現小錯誤，最大的問題是您實際上正在讀取圖像，然後將其保存到文件中。這會導致不必要的圖像處理和保存的其他文件（它看起來相同，但下載的文件將與服務器上的文件不同） – 2012-02-27 09:10:47

你不應該在ms和img對象調用Dispose()，直到你在最後它保存到文件中。

他們甚至在自己的using段中聲明，所以你不需要調用它們的Dispose()可言，因爲它是自動設置在每個使用區塊的出口（這是真正使用using的主要原因首先！）。

來源

2012-02-27 09:19:51 awe

從URL獲取圖片，但未完全加載

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