iOS 自带分享功能

1.直接分享（指定类型，比如微博）

        // 首先判断新浪分享是否可用
        if (![SLComposeViewController isAvailableForServiceType:SLServiceTypeSinaWeibo]) {
            return;
        }
        // 创建控制器，并设置ServiceType
        SLComposeViewController *composeVC = [SLComposeViewController composeViewControllerForServiceType:SLServiceTypeSinaWeibo];
        // 添加要分享的图片
        [composeVC addImage:[UIImage imageNamed:@"SinaWeibo"]];
        // 添加要分享的文字
        [composeVC setInitialText:@"share my Blog"];
        // 添加要分享的url
        [composeVC addURL:[NSURL URLWithString:@"http://chrispangpang.github.io"]];
        // 弹出分享控制器
        [self presentViewController:composeVC animated:YES completion:nil];
        // 监听用户点击事件
        composeVC.completionHandler = ^(SLComposeViewControllerResult result){
            if (result == SLComposeViewControllerResultDone) {
                NSLog(@"点击了发送");
            }
            else if (result == SLComposeViewControllerResultCancelled)
            {
                NSLog(@"点击了取消");
            }
        };

2.非直接分享（弹出一个板板，自己选）

UIActivityViewController *avc = [[UIActivityViewController alloc]initWithActivityItems:@[@"分享给你",[NSURL URLWithString:@"http://chrispangpang.github.io"]] applicationActivities:nil];
 [self presentViewController:avc animated:YES completion:nil];

模拟器可能会出现此类提醒（真机不会）

Class PLBuildVersion is implemented in both /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/System/Library/PrivateFrameworks/AssetsLibraryServices.framework/AssetsLibraryServices (0x129355910) and /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/System/Library/PrivateFrameworks/PhotoLibraryServices.framework/PhotoLibraryServices (0x12917f210). One of the two will be used. Which one is undefined.

参考
http://www.cocoachina.com/industry/20140425/8233.html