Check if file exist with Try/Catch

Question

I'm new to this about Try/Catch. In the code below I have a simple test to check if a file exist. In my task for my C# lesson I must use Try/Catch, and I'm not sure how to use this, should I still use the if statement inside the Try part or is there a better way to do the checking if a file exist inside Try? Is there any difference if the file is a simple txt file or a serialized file?

if (File.Exists("TextFile1.txt"))
{
   MessageBox.Show("The file don't exist!", "Problems!", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
}

The Try/Catch way I must use

try
{
code to check if file exist here
}
catch
{
error message here
}

Solution 1

You already check on the presence of file in your first sniplet. There is no any need, for this code to be inside try/catch block.

Solution 2

try
{
 if (!File.Exists("TextFile1.txt"))
    throw new FileNotFoundException();
}
catch(FileNotFoundException e)
{
   // your message here.
}

Solution 3

If you want to check if the file exists without using File.Exist, then you may try opening the file in a try block, and then catching the exception FileNotFoundException.

try
    {
        // Read in non-existent file.
        using (StreamReader reader = new StreamReader("TextFile1.txt"))
        {
        reader.ReadToEnd();
        }
    }
catch (FileNotFoundException ex)
    {
        MessageBox.Show("The file don't exist!", "Problems!", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
        // Write error.
        Console.WriteLine(ex);
    }

Solution 4

Try this :

try
{
   if(!File.Exist("FilePath"))
       throw new FileNotFoundException();

   //The reste of the code
}
catch (FileNotFoundException)
{
    MessageBox.Show("The file is not found in the specified location");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

Solution 5

Use throw:

try
{
    if (!File.Exists("TextFile1.txt"))
        throw (new Exception("The file don't exist!"));
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

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