C#, file system

[khore]

Hi

Sorry I have to post another thread be4 leaving to the uni!

I have a problem with file system. I have a phonebook service with has 2 methods:

Set: adds new items to phone book
lookup: looking up a name to find its tel.number.

If first i use "set" and then "lookup" it's ok! But when first i look up a name and when i can't find it , i try to add it to phone book , i got this error: Access to this fileis not possible, becaz this file is in used by another process.

here is my code:

public int lookup(String name)
        {
         try
            {
                StreamReader SR;
                SR = File.OpenText("c:\\phone book.txt");
                String S = "test";
                while (S != null)
                {
                    String read = SR.ReadLine();
                    if (read.Substring(0, name.Length).Equals(name))
                    {
                        int number = Convert.ToInt32read.Substring(name.Length);
                        SR.Close();
                        return address;
                    }
                }
            }
 
            catch (Exception e)
            {
                   }
  -----------------------------------------------------------------------------------------------------------------
public void set (String name, int number){
 
            System.IO.StreamWriter SW = new System.IO.StreamWriter("c:\\Yellow Page.txt",true);
            try
            {
                String input = (name + number).ToString;
                 SW.WriteLine(input);
                SW.Close();
 
            }
            catch (IOException e)
            {
 
            }

Thank u inadvanced and sorry for posting 2 threads in a short time :-S

[IanWright]

Think about what happens if an Exception is thrown during the lookup method. Try putting a break point on SR.Close() and you should see what I mean.

Now try something along the lines of

StreamReader streamReader = new StreamReader(...);
 
try
{
     // Read from the streamReader 
}
catch()
{}
finally
{
   streamReader.Close();
}