Inactive button in UIAlert View

In my iphone-app, I have a "Share" button in my Navigation bar, that pops up a UIAlertView with the options "Twitter" and "Facebook". When a user has already sent something to Twitter, I don't want him to be able to sent it again.

One way开发者_运维技巧 of preventing this, is to just remove the Twitter button from that Alert. This makes the Alert kind of inconsistent/unpredictable, and I would rather 'grey out' the Twitter button.

Is there a better way of doing this?

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Based on what you are doing, you should use an UIActionSheet. It follows the HIG and then you can control the UX a bit better.

When you tap share, just create the action sheet with whatever options you want to allow the user to select.