title: The process cannot access the file
body: <p>I have a program that I use to write data to an excel file.... and at the same time I use an excel file to import data from the first excel file using (import data) tool.</p>
  
  <p>This is part of the program code : </p>
  
  <pre><code>private void Log(string pText)
  {
      //textBox1.AppendText(pText + "\r\n"); // does not put cr lf, why?
      this.BeginInvoke(new MethodInvoker(delegate () {
          textBox1.AppendText(pText);
          textBox1.AppendText("\n");
      }));
  }
  
  private void LogStatus(string pText)
  {
      textBox1.AppendText(pText + "\t");
      textBox1.AppendText("\n");
  }
  
  
  StreamWriter theString = new StreamWriter(FileName + ".csv", true);
  theString.WriteLine(DateTime.Now + dataToSave + "\t\n");
  theString.Close();
  </code></pre>
  
  <p>my problem is when i start to debuge my program in Visual C# 2008</p>
  
  <p>it will work will and start to write data to the first excel file....then during the debug process</p>
  
  <p>i want to import data from the first excel file to the second one using import data(it's important for me to do that in real time i cant delay the import process)</p>
  
  <p>the debuging process stopped and the visual C# 2008  higlight this line of the code</p>
  
  <hr>
  
  <pre><code> theString.Close();
  </code></pre>
  
  <hr>
  
  <p>and a message popup to me said</p>
  
  <p>The process cannot access the file because another process has locked a portion of the file.</p>
  
  <p>any help in overcome this problem plz</p>
  
  <p>and thanks</p>