C# : Method name expected

Question

I have that method that counts files in a certain folder:

    private void countfiles(string path)
    {
        if (path != "")
        {
            DirectoryInfo dir = new DirectoryInfo(path);

            foreach (FileInfo filesindires in dir.GetFiles())
            {
                if (filesindires.FullName != Application.ExecutablePath)
                {
                    num_files++;
                    Thread.Sleep(1);
                }
            }

            foreach (DirectoryInfo dirsinfolder in dir.GetDirectories())
            {
                countfiles(dirsinfolder.FullName);
            }
        }           
    }

and when the user clicks on the count button I wanted to make a thread, so the program doesn't hang.

Thread count = new Thread(new ThreadStart(countfiles(@"E:/test")));

But I get this error even before debugging:

Method Name Expected

I dont understand; what does that error need from me?

Finally thanks a lot for your help in advance.

Answer 1

It's

Thread count = new Thread(new ParameterizedThreadStart(countfiles));    
count.Start(@"E:/test");

You don't have to pass the parameters, just the method name.

Also you will need to change the type of the parameter to object, not string. Alternatively, if you want to keep the string parameter, you can use:

Thread count = new Thread(
   o => 
   {
       countFiles((string)o);    
   });
count.Start(@"E:/test");

Answer 2

The problem is here:

new ThreadStart(countfiles(@"E:/test"))

The argument is a method-call trying to masquerade as a method-group. The compiler can turn a compatible method-group, lambda expression or anonymous method to a delegate-type but not a method call.

Try one of these :

// Lambda
var thread = new Thread(() => countfiles(@"E:/test")); 

// Anonymous method
var thread = new Thread( delegate() { countfiles(@"E:/test"); }); 

If you want to use a method-group, you'll need a separate method:

private void CountTestFiles()
{
     countFiles(@"E:/test");
}

and then you can do:

// Method-group
var thread = new Thread(CountTestFiles) 

You could also work with the ParameterizedThreadStart delegate-type and the associated overloads of the Thread constructor, but it's a little awkward to work with since the argument is object, so a cast somewhere or the other will be unavoidable.