C#

JoeRip wrote:

how do you compare exceptions?

try
{
   // do some code
}
catch (System.NullReferenceException)
{
   // do cleanup for handling a null reference
}
catch (System.InvalidOperationException)
{
   // do some other cleanup
}

try
{
   // do some code that throws an ArgumentNullException
}
catch (System.ArgumentException)
{
   // do cleanup for handling a general argument exception
}
catch (System.ArgumentNullException)
{
   // this handler will never be run
}
 
try
{
   // do some code that throws an ArgumentNullException
}
catch (System.ArgumentNullException)
{
   // this handler will be run
}
catch (System.ArgumentException)
{
   // do cleanup for handling a general argument exception
}

JoeRip wrote:

So it stands to reason that you can somehow say "if myException is X, do this" somehow.

SqlConnection connection = new SqlConnection("your connection string goes here");
SqlCommand myCommand = new SqlCommand("Select * from MyTable");
myCommand.Connection = connection;
SqlDataReader reader = myCommand.ExecuteReader();
while(reader.Reader())
{
   // This will pull a string from the first column in the MyTable
   string nodeText = reader.GetString(0);

   // This will create a tree node and add it to the tree view. 
   TreeNode node = new TreeNode(nodeText);
   myTreeView.Nodes.Add(node);
}

System.Data.SqlClient.SqlException was unhandled<br />
  Message="An error has occurred while establishing a connection to the server.  When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)"

Ennis Ray Lynch, Jr. wrote:

Professional C# 2005 is not a professional level book.