How do I implement a Voting system?

Question

I am required to implement a functionality similar to SO voting. I tried to look up some existing questions around this topic and noticed that most people are stuck with how to vote up and down. i am past that. my problem is related to how to handle after a vote has been upvoted. here is what i have done till now.

1. Vote up, Down and Score displayed for each answer.
2. Vote count changed when user clicks up or down and the image is updated accordingly.
3. Save the information in db like. who voted, time of vote, type of vote, userIP, ansID, etc.

Now the questions.

1. I am using a gridview to display information. how do i show the previously voted answers as voted on next page load. I have the information in db but i want to do this without affecting performance. I could do it in itemDatabound event but it doesnt look like a pretty way to handle it. i wonder if there is a better way to handle such situation
2. Toggle Votes : When a user toggles a vote, what happens behind the scenes. is the previous upvoted record deleted or not? i say it should be deleted but want a confirmation.
3. Is gridview a good way to implement such functionality or not?

Answer 1

For

1) If you are using a gridview you almost have to take this route. But we need more details about what you are trying to do.

2) When you upvote and then downvote that same answer / question it should be checked and deleted. Remember you are only allowed 1 vote for a question or answer so your database table should be written so that their is a unique row for a userID, a QuestionID (given that a question is unique). So you should not even allow it to insert duplicate rows in a table.

3)stackoverflow is mvc type app, you are using webforms, so you could use a gridview or a listview. They are probably just looping through the answers and generating the html (as this is MVC).