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How would I write a message when there are no files to process in the foreach loop?

Posted on 2016-11-11
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Last Modified: 2016-11-11
I am writing a C# application.

I use:  foreach (string file in files1)
            {              
            }

How would I write a message when there are no files to process in the foreach loop?
0
Comment
Question by:zimmer9
5 Comments
 

Expert Comment

by:Omar Alaa
ID: 41884051
please make it clear what is files 1 and what is your problem exactly
0
 
LVL 63

Expert Comment

by:Fernando Soto
ID: 41884055
Please post the actual code and declarations of those variable not declared in the code.
0
 

Author Comment

by:zimmer9
ID: 41884068
In the following function, how would I exit the application and inform the user that there are no files to process?


public static void ProcessDirectory(string TARGET_DIR_IN, StreamWriter sw1)
        {
            string[] files1 = Directory.GetFiles(TARGET_DIR_IN, "*_FRONT.TIF").Select(path => Path.GetFileName(path)).ToArray();
            string[] files2 = Directory.GetFiles(TARGET_DIR_IN, "*_REAR.TIF").Select(path => Path.GetFileName(path)).ToArray();
            ManualResetEvent[] doneEvents = new ManualResetEvent[files1.Length];
            _numerOfThreadsNotYetCompleted = files1.Length;
            int i = 0;

            foreach (string file in files1)
            {
                string checkPrefix = file.ToUpper().Replace("_FRONT.TIF", "");
                string checkBack = checkPrefix + "_Rear.TIF";
                string checkImage = checkPrefix + ".tif";
                file_tif_date = checkPrefix.Substring(0, 8);

                if (File.Exists(TARGET_DIR_IN + checkBack))
                {
                    if (!File.Exists(TARGET_DIR_IN + checkImage))
                    {

                        //doneEvents[ I ] = new ManualResetEvent(false);
                        ProcessImageThread chk = new ProcessImageThread(checkPrefix, TARGET_DIR_IN);
                        ThreadPool.QueueUserWorkItem(chk.ProcessImage, i);
                        i++;
                    }
                }
                else
                {              
                    sw1.WriteLine(checkBack + " file is missing");
                    if (sw1 != null) sw1.Close();
                    Environment.Exit(0);                    
                }
            }

            //Wait for all threads in pool to calculation...
            //WaitHandle.WaitAll(doneEvents);

            _doneEvent.WaitOne();

            //Console.WriteLine("All image processing are completed.");

            foreach (string file in files2)
            {
                string checkPrefix = file.ToUpper().Replace("_REAR.TIF", "");
                string checkFront = checkPrefix + "_FRONT.TIF";

                if (File.Exists(TARGET_DIR_IN + checkFront))
                {
                }
                else
                {
                    sw1.WriteLine(checkFront + " file is missing");
                }
            }

            if (sw1 != null) sw1.Close();
        }
0
 
LVL 63

Accepted Solution

by:
Fernando Soto earned 500 total points
ID: 41884176
Hi zimmer9;

In both of the foreach loops it will continue to execute the foreach as long as there are items in the collection, in this case files1 and files2. So if you want to post some message when there are no more files to process in files1 then do it as the first statement after that foreach loop and the same goes for files2 foreach loop.
0
 
LVL 33

Expert Comment

by:it_saige
ID: 41884196
Just check the count (or length) before you enter your loop and take the appropriate action, if any; e.g. -
public static void ProcessDirectory(string TARGET_DIR_IN, StreamWriter sw1)
{
	string[] files1 = Directory.GetFiles(TARGET_DIR_IN, "*_FRONT.TIF").Select(path => Path.GetFileName(path)).ToArray();
	string[] files2 = Directory.GetFiles(TARGET_DIR_IN, "*_REAR.TIF").Select(path => Path.GetFileName(path)).ToArray();
	ManualResetEvent[] doneEvents = new ManualResetEvent[files1.Length];

	if (files1.Count() == 0)
	{
		// You can generate a message or output or whatever to alert that there are no files to process
		Console.WriteLine("There are no front images to process");

		// Return from the method
		return;
	}

	_numerOfThreadsNotYetCompleted = files1.Length;
	int i = 0;

	foreach (string file in files1)
	{
		string checkPrefix = file.ToUpper().Replace("_FRONT.TIF", "");
		string checkBack = checkPrefix + "_Rear.TIF";
		string checkImage = checkPrefix + ".tif";
		file_tif_date = checkPrefix.Substring(0, 8);

		if (File.Exists(TARGET_DIR_IN + checkBack))
		{
			if (!File.Exists(TARGET_DIR_IN + checkImage))
			{
				//doneEvents[ I ] = new ManualResetEvent(false);
				ProcessImageThread chk = new ProcessImageThread(checkPrefix, TARGET_DIR_IN);
				ThreadPool.QueueUserWorkItem(chk.ProcessImage, i);
				i++;
			}
		}
		else
		{
			sw1.WriteLine(checkBack + " file is missing");
			if (sw1 != null) sw1.Close();
			Environment.Exit(0);
		}
	}

	//Wait for all threads in pool to calculation...
	//WaitHandle.WaitAll(doneEvents);

	_doneEvent.WaitOne();

	//Console.WriteLine("All image processing are completed.");

	if (files2.Count() == 0)
	{
		// You can generate a message or output or whatever to alert that there are no files to process
		Console.WriteLine("There are no back images to process");

		// Return from the method
		return;
	}

	foreach (string file in files2)
	{
		string checkPrefix = file.ToUpper().Replace("_REAR.TIF", "");
		string checkFront = checkPrefix + "_FRONT.TIF";

		if (File.Exists(TARGET_DIR_IN + checkFront))
		{
		}
		else
		{
			sw1.WriteLine(checkFront + " file is missing");
		}
	}

	if (sw1 != null) sw1.Close();
}

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-saige-
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