Why does this IF statement fail?

Question

If variable path is empty, and editor.Text is not empty, the SaveFileDialog should be displayed.

Now, why on earth is this damn thing failing???

I have tried this with many different variations of code with the same result: FAIL:

if(path.Length >= 1) // path contains a path. Save changes instead of creating NEW file.
{
   File.WriteAllText(path, content);
}
else
{
   // no path defined. Create new file and write to it.
   using(SaveFileDialog saver = new SaveFileDialog())
   {
      if(saver.ShowDialog() == DialogButtons.OK)
      {
         File.WriteAllText(saver.Filename, content);
      }
   }
}

At the top of code file I have:

path = String.Empty;

So why the heck it this failing every single time, even after trying all of the below variations?

if(path.Length > 1) // path contains a path. Save changes instead of creating NEW file.
{
   File.WriteAllText(path, content);
}
else
{
   // no path defined. Create new file and write to it.
   using(SaveFileDialog saver = new SaveFileDialog())
   {
      if(saver.ShowDialog() == DialogButtons.OK)
      {
         File.WriteAllText(saver.Filename, content);
      }
   }
}

and

if(String.IsNullOrEmpty(path)) // path contains a path. Save changes instead of creating NEW file.
{
   File.WriteAllText(path, content);
}
else
{
   // no path defined. Create new file and write to it.
   using(SaveFileDialog saver = new SaveFileDialog())
   {
      if(saver.ShowDialog() == DialogButtons.OK)
      {
         File.WriteAllText(saver.Filename, content);
      }
   }
}

and

if(String.IsNullOrWhiteSpace(path)) // path contains a path. Save changes instead of creating NEW file.
{
   File.WriteAllText(path, content);
}
else
{
   // no path defined. Create new file and write to it.
   using(SaveFileDialog saver = new SaveFileDialog())
   {
      if(saver.ShowDialog() == DialogButtons.OK)
      {
         File.WriteAllText(saver.Filename, content);
      }
   }
}

This is making me very angry. How could this fail?

Setting a break point reveals that path is definitely null / "" .

Answer 1

Why you've written:

if(saver.ShowDialog() == DialogButtons.OK)

Instead of:

if(saver.ShowDialog() == DialogResult.OK)

Answer 2

If path is null , you're going to get an exception when trying to get path.Length . To check for an empty path, use the String.IsNullOrWhiteSpace(path) version. You also need a condition to check your second requirement.

if(!String.IsNullOrWhiteSpace(path)) // path contains a path. Save changes instead of creating NEW file.
{
   File.WriteAllText(path, content);
}
else if (!String.IsNullorWhiteSpace(editor.Text))
{
   // no path defined. Create new file and write to it.
   using(SaveFileDialog saver = new SaveFileDialog())
   {
      if(saver.ShowDialog() == DialogResult.OK)
      {
         File.WriteAllText(saver.Filename, content);
      }
   }
}

Answer 3

the path is a string and its the fullpath to your file? if its filled then it doesnt mean that the file really exists, you better go that way:

if(System.IO.File.Exists(path))
{

}
else
{

}

File.Exists(null) returns false, so this will work fine

if you wanna use your way, then i guess your last two statements are just missing a "!"

if (!String.IsNullOrWhiteSpace(path)) 

if(!String.IsNullOrEmpty(path))

check if null before access the length property

if(path != null && path.Length > 1) 

Answer 4

Try this:

 if (string.IsNullOrWhiteSpace(path) && !string.IsNullOrWhiteSpace(editor.Text))
 {
       // no path defined. Create new file and write to it.
       using (SaveFileDialog saver = new SaveFileDialog())
       {
            if (saver.ShowDialog() == DialogResult.OK)
            {
                 File.WriteAllText(saver.Filename, content);
            }
       }                
  }
  else if(File.Exists(path)
  {
       File.WriteAllText(path, content);
  }