如何将异常保存在txt文件中？

public DataTable InsertItemDetails(FeedRetailPL objFeedRetPL)
{
    DataTable GetListID = new DataTable();
    try
    {
        SqlParameter[] arParams = new SqlParameter[4];

        arParams[0] = new SqlParameter("@Date", typeof(DateTime));
        arParams[0].Value = objFeedRetPL.requestdate;

    }
    catch (Exception ex)
    {
        string dir = @"C:\Error.txt";  // folder location
        if (!Directory.Exists(dir))
        {
            Directory.CreateDirectory(dir);
            File.AppendAllText(Server.MapPath("~/Error.txt"), "Message :" + ex.Message + "<br/>" + Environment.NewLine + "StackTrace :" + ex.StackTrace +
       "" + Environment.NewLine + "Date :" + DateTime.Now.ToString());
            string New = Environment.NewLine + "-----------------------------------------------------------------------------" + Environment.NewLine;
            File.AppendAllText(Server.MapPath("~/Error.txt"), New);
        }
    }
}

在这里，我想在“C:\”中保存异常..我正在尝试在 DAL 中...如何将异常保存在 C盘错误.txt

因为您想将异常保存到C:\Error.txt，你不需要Directory.Exists, Directory.CreateDirectory, or Server.MapPath("~/Error.txt")。你可以简单地使用流写入器 http://msdn.microsoft.com/en-us/library/36b035cb.aspx像这样：

string filePath = @"C:\Error.txt";

Exception ex = ...

using( StreamWriter writer = new StreamWriter( filePath, true ) )
{
    writer.WriteLine( "-----------------------------------------------------------------------------" );
    writer.WriteLine( "Date : " + DateTime.Now.ToString() );
    writer.WriteLine();

    while( ex != null )
    {
        writer.WriteLine( ex.GetType().FullName );
        writer.WriteLine( "Message : " + ex.Message );
        writer.WriteLine( "StackTrace : " + ex.StackTrace );

        ex = ex.InnerException;
    }
}

上面的代码将创建C:\Error.txt如果不存在，或者追加C:\Error.txt如果它已经存在。