I\'m writing a C# app that will be required to integrate with twitter, I need to be able to do the following:
I know that this post got marked as answered but I wanted to share how easy it is to send messages to multiple users at once with Tweetinvi (http://tweetinvi.codeplex.com/).
IToken token = new Token("userKey", "userSecret", "consumerKey", "consumerSecret");
ITokenUser u = new TokenUser(token);
// Publish Direct Message to all the followers
u.PublishMessage("Hello world!", u.followers);
// Done!
I believe this can be of great help to develop a twitter bot.
Another option is LINQ to Twitter. This is a 3rd party LINQ provider that I created that allows developers to interact with the Twitter API. If you're writing a C# application to interact with Twitter, this is another option in addition to the other libraries mentioned in other posts.
See available APIs here
I think most preferable will be Yedda Twitter Library
Here is a better option if you are after a light-weight solution.
I wrote a Twitter Bot in C# for @valuetraderteam, it runs a heartbeat on a schedule and performs GET/POST actions to send website related tweets and add/remove friends from my list.
The API component in the GIST below is less than 500 lines, should be easy enough to add it to any project, only dependency is Json.NET which you might already have installed.
https://gist.github.com/sdesalas/c82b92200816ecc83af1
Hopefully this is useful to some other people out there.
I prefer using Twitterizer.
TweetSharp can take care of both those requirements.
Yedda doesn't support Direct Messages as of now.