C# – Can you call Directory.GetFiles() with multiple filters

cfilesystemsnet

I am trying to use the Directory.GetFiles() method to retrieve a list of files of multiple types, such as mp3's and jpg's. I have tried both of the following with no luck:

Directory.GetFiles("C:\\path", "*.mp3|*.jpg", SearchOption.AllDirectories);
Directory.GetFiles("C:\\path", "*.mp3;*.jpg", SearchOption.AllDirectories);

Is there a way to do this in one call?

Best Answer

For .NET 4.0 and later,

var files = Directory.EnumerateFiles("C:\\path", "*.*", SearchOption.AllDirectories)
            .Where(s => s.EndsWith(".mp3") || s.EndsWith(".jpg"));

For earlier versions of .NET,

var files = Directory.GetFiles("C:\\path", "*.*", SearchOption.AllDirectories)
            .Where(s => s.EndsWith(".mp3") || s.EndsWith(".jpg"));

edit: Please read the comments. The improvement that Paul Farry suggests, and the memory/performance issue that Christian.K points out are both very important.

Related Solutions

C# – Catch multiple exceptions at once

Catch System.Exception and switch on the types

catch (Exception ex)            
{                
    if (ex is FormatException || ex is OverflowException)
    {
        WebId = Guid.Empty;
        return;
    }
    
    throw;
}

C# – String representation of an Enum

Try type-safe-enum pattern.

public sealed class AuthenticationMethod {

    private readonly String name;
    private readonly int value;

    public static readonly AuthenticationMethod FORMS = new AuthenticationMethod (1, "FORMS");
    public static readonly AuthenticationMethod WINDOWSAUTHENTICATION = new AuthenticationMethod (2, "WINDOWS");
    public static readonly AuthenticationMethod SINGLESIGNON = new AuthenticationMethod (3, "SSN");        

    private AuthenticationMethod(int value, String name){
        this.name = name;
        this.value = value;
    }

    public override String ToString(){
        return name;
    }

}

Update Explicit (or implicit) type conversion can be done by

adding static field with mapping
```
private static readonly Dictionary<string, AuthenticationMethod> instance = new Dictionary<string,AuthenticationMethod>();
```
- n.b. In order that the initialisation of the the "enum member" fields doesn't throw a NullReferenceException when calling the instance constructor, be sure to put the Dictionary field before the "enum member" fields in your class. This is because static field initialisers are called in declaration order, and before the static constructor, creating the weird and necessary but confusing situation that the instance constructor can be called before all static fields have been initialised, and before the static constructor is called.
filling this mapping in instance constructor
```
instance[name] = this;
```

and adding user-defined type conversion operator

public static explicit operator AuthenticationMethod(string str)
{
    AuthenticationMethod result;
    if (instance.TryGetValue(str, out result))
        return result;
    else
        throw new InvalidCastException();
}

Best Answer

Related Solutions

C# – Catch multiple exceptions at once

C# – String representation of an Enum

Related Topic