MFMessageComposeViewController

-(void)sendMessage{
     [self showMessageView: @"13800138000" title:@"验证短信" body:[NSString stringWithFormat:@"请不要修改认证短信，直接将本条认证短信发送给我们，以完成手机验证。（%d）",arc4random() % 1000000]];
}

-(void)showMessageView : (NSString *)phone title : (NSString *)title body : (NSString *)body
{
    if( [MFMessageComposeViewController canSendText] )
    {
        MFMessageComposeViewController * controller = [[MFMessageComposeViewController alloc] init];
        controller.recipients = [NSArray arrayWithObject:phone];
        controller.body = body;
        controller.messageComposeDelegate = self;
        [self presentModalViewController:controller animated:YES];
        
        [[[[controller viewControllers] lastObject] navigationItem] setTitle:title];//修改短信界面标题
    }
    else
    {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示信息"
                                                        message:@"该设备不支持短信功能"
                                                       delegate:nil
                                              cancelButtonTitle:@"确定"
                                              otherButtonTitles:nil, nil];
        [alert show];
    }
}

-(void)messageComposeViewController:(MFMessageComposeViewController *)controller didFinishWithResult:(MessageComposeResult)result
{

    [self dismissModalViewControllerAnimated:YES];

    switch (result) {
        case MessageComposeResultCancelled:
        {
            //click cancel button
        }
            break;
        case MessageComposeResultFailed:// send failed

            break;
           
        case MessageComposeResultSent:
        {
            //do something
        }
            break;
        default:
            break;
    }

}