how to redirect to itunes app page from an app

NSURL * url = [[NSURLalloc] initWithString:@"itms-apps://itunes.com/apps/appname"];

    [[UIApplicationsharedApplication] openURL:url];

上述来下面提示.

From http://developer.apple.com/iphone/news/archives/2010/january/

Drive Customers Directly to Your App on the App Store with iTunes Links With iTunes links you can provide your customers with an easy way to access your apps on the App Store directly from your website or marketing campaigns. Creating an iTunes link is simple and can be made to direct customers to either a single app, all your apps, or to a specific app with your company name specified.

To send customers to a specific application: http://itunes.com/apps/appname

To send customers to a list of apps you have on the App Store:http://itunes.com/apps/developername

To send customers to a specific app with your company name included in the URL:http://itunes.com/apps/developername/appname

Additional notes:

You can replace http:// with itms:// or itms-apps:// to avoid redirects.

For info on naming, see QA1633: https://developer.apple.com/library/ios/#qa/qa1633/_index.html