私は複数のスレッドでSQLコマンドを呼び出せません。C＃

Question

だから私はdatagridviewで呼び出しを行い、それを実行する最初のスレッドでうまく動作するメソッドを持っていますが、2番目のスレッドがメソッドを利用しようとすると、機能は、しかし、呼び出し文が最初のスレッドのために働くと多分これがお手伝いします

public void ByteTransferResume(int indexResume) 
{ 
    HttpWebRequest req; 
    HttpWebResponse resp; 
    req = (HttpWebRequest)HttpWebRequest.Create(FileLocationName); 
    req.AddRange((int)fileInfoDestination.Length); 
    resp = (HttpWebResponse)(req.GetResponse()); 
    long fileLength = resp.ContentLength; 
    FileLocationLength = fileLength; 
    using (Stream responseStream = resp.GetResponseStream()) 
    { 
     int iBufferSize = 1024; 
     iBufferSize *= 1000; 
     using (FileStream saveFileStream = new FileStream(FileDestination, FileMode.Append, FileAccess.Write, FileShare.ReadWrite)) 
     { 
      int iByteSize; 
      byte[] downBuffer = new byte[iBufferSize]; 

      while ((iByteSize = responseStream.Read(downBuffer, 0, downBuffer.Length)) > 0) 
      { 
       saveFileStream.Write(downBuffer, 0, iByteSize); 

       FileInfo fileInfoDestinations = new FileInfo(FileDestination); 

       FileDestinationLength = (int)fileInfoDestinations.Length; 

       double downloadProgress = ((double)FileDestinationLength/FileLocationLength) * 100; 

       // MessageBox.Show(downloadProgress.ToString()); 

       dgvDownloadInfo.Invoke(new dgvCommandDelegate(DGVCommand), new object[] { $"UPDATE Download_Info SET [Progress] = '{downloadProgress:F2}%' WHERE [File Name] = '{thread1[indexResume].Name}'" }); 

       //MessageBox.Show(thread1[indexResume].Name); 
       //MessageBox.Show(indexResume.ToString()); 
       // dgvDownloadInfo.Invoke(new dgvConnectionDelegate(DGVConnection)); 
       Thread.Sleep(10); 
      } 
     } 
    } 
} 

Answer 1

の両方を変更するには開始、停止、まだそれの一部をダウンロードしてください：

public object _lock = new object(); 
public void ByteTransferResume(int indexResume) 
{ 
    lock (_lock) 
    { 
     HttpWebRequest req; 
     //rest of your method   
    } 
    }