Ok, so can you even begin to tell me how many files you have on your
computer? I can't either. There are so many reasons you could need to
get file listings in C#, and thanks to the System.IO
namespace,
doing so is just about as easy as including the namespace itself. Really
all you need to do is create a variable, then a loop.
So all the magic happens due to a couple of nice and simple classes in
the System.IO namespace, called
DirectoryInfo
and
FileInfo.
Really, with these two classes you can do a lot of cool stuff, directory
and file wise that is. Not only do these classes make file and directory
listing really simple, but they are actually more powerful than they
seem.
Anyway, in order to get started, you must first include the System.IO
namespace, mainly because it is not used by default. So add it to the
top of your code. Next we are going to make a new DirectoryInfo
instance, and in this case we are using the root drive of C:\, so your
code should look like:
DirectoryInfo fileListing = new DirectoryInfo("C:\\");
This code does exactly what you would think, it takes the directory and
allows you to get all kinds of information about it. You can use this
one variable to find out all kinds of things, anything from directory
permissions to the last modified date. Now, this little snippet will
only cover the basics, but when you are looking at more, just remember
listing files is only the simplest of things you can do.
Now that we have our DirectoryInfo object, we can loop through all the
files in that directory and do whatever we like with them. In this case,
we are just going to fill a listbox with the full file path. To do this,
all we need to do is call the
GetFiles()
method, which returns an array of FileInfo objects. Each FileInfo has a
ton of information on each file, but all we really need is the name
right now. So our final code might look something like:
DirectoryInfo fileListing = new DirectoryInfo("C:\\");
foreach (FileInfo file in fileListing.GetFiles())
{
listBox1.Items.Add(fileListing.ToString() + file.Name);
}
Super simple, but lets be honest with ourselves, how often do you want
all the files in a directory? Not very often I would think. Luckily, the
GetFiles() method has an argument to limit what files you get. This
argument is just a string that you can add a search pattern to. So say
we want to search for .txt files. Our updated code would look like so:
DirectoryInfo fileListing = new DirectoryInfo("C:\\");
foreach (FileInfo file in fileListing.GetFiles("*.txt"))
{
listBox1.Items.Add(fileListing.ToString() + file.Name);
}
The one downside to using the search pattern is that you can only use
one of them. As far as I know you can only use one search pattern in the
string, so in order to get multiple file types, you have to call the
method again with a different pattern. That being said, it is not too
much of an inconvenience being as easy as it is.
So that is pretty much how you can get the files in a current directory.
Super simple and super fast. You can do all kinds of things with the
DirectoryInfo and FileInfo classes, so I would check them out if you
can.
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