AFOAuth1Client 介绍
AFNetworking 的扩展，用于支持 OAuth 1.0a 认证。
示例代码：
AFOAuth1Client *twitterClient = [[[AFOAuth1Client alloc] initWithBaseURL:[NSURL URLWithString:@"https://twitter.com/oauth/"] key:@"..." secret:@"..."] autorelease];
// Your application will be sent to the background until the user authenticates, and then the app will be brought back using the callback URL
[twitterClient authorizeUsingOAuthWithRequestTokenPath:@"/request_token" userAuthorizationPath:@"/authorize" callbackURL:[NSURL URLWithString:@"x-com-YOUR-APP-SCHEME://success"] accessTokenPath:@"/access_token" success:^(AFOAuth1Token *accessToken) {
NSLog(@"Success: %@", accessToken);
NSLog(@"Your OAuth credentials are now set in the `Authorization` HTTP header");
} failure:^(NSError *error) {
NSLog(@"Error: %@", error);
}];