[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"sms://800888"]];

- (void)showSMSPicker:(id)sender
{
   /**
   您必须检查当前设备是否可以在尝试创建一个MFMessageComposeViewController的实例之前发送短信
   。 如果设备无法发送短信，
   [[MFMessageComposeViewController alloc] init]将返回nil。 您的应用程式用一个空视图控制器调用
   -presentViewController时会导致崩溃。
   **/
  if ([MFMessageComposeViewController canSendText])
    // The device can send email.
  {
    [self displaySMSComposerSheet];
  }
  else
    // The device can not send email.
  {
    self.feedbackMsg.hidden = NO;
    self.feedbackMsg.text = @"Device not configured to send SMS.";
  }
}

- (void)displaySMSComposerSheet
{
  MFMessageComposeViewController *picker = [[MFMessageComposeViewController alloc] init];
  picker.messageComposeDelegate = self;
  
  //您可以指定一个或多个预配置的收件人。 用户有从消息编辑器视图中删除或添加收件人的选项控制器
  //您可以指定将出现在消息编辑器视图控制器中的初始消息文本。
  
  picker.recipients = @[@"Phone number here"];//发短信的手机号码的数组，数组中是一个即单发,多个即群发。
  picker.body    = @"Hello from California!"; //短信主体内容
  
  [self presentViewController:picker animated:YES completion:NULL];
}

- (void)viewDidLoad {
  [super viewDidLoad];
  // Do any additional setup after loading the view, typically from a nib.
  
  UIButton * button = [[UIButton alloc]initWithFrame:CGRectMake(140, 100, 100, 100)];
  button.backgroundColor = [UIColor blackColor];
  [button setTitle:@"发送短信" forState:UIControlStateNormal];
  [button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
  [button addTarget:self action:@selector(showSMSPicker:) forControlEvents:UIControlEventTouchUpInside];
  [self.view addSubview:button];
  
  UILabel * feedbackMsg = [[UILabel alloc]initWithFrame:CGRectMake(10, 300, self.view.frame.size.width -20, 30)];
  feedbackMsg.textAlignment = NSTextAlignmentCenter;
  [self.view addSubview:feedbackMsg];
  self.feedbackMsg = feedbackMsg;
}

// -------------------------------------------------------------------------------
// messageComposeViewController:didFinishWithResult:
// Dismisses the message composition interface when users tap Cancel or Send.
// Proceeds to update the feedback message field with the result of the
// operation.
// 当用户点击取消或发送时，关闭消息组合界面。
// 收到更新反馈消息字段的结果操作。
// -------------------------------------------------------------------------------
- (void)messageComposeViewController:(MFMessageComposeViewController *)controller 
       didFinishWithResult:(MessageComposeResult)result
{
  self.feedbackMsg.hidden = NO;
  // Notifies users about errors associated with the interface
  // 通知用户与界面相关的错误
  switch (result)
  {
    case MessageComposeResultCancelled: //取消
      self.feedbackMsg.text = @"Result: SMS sending canceled";
      break;
    case MessageComposeResultSent: //发送
      self.feedbackMsg.text = @"Result: SMS sent";
      break;
    case MessageComposeResultFailed: //失败
      self.feedbackMsg.text = @"Result: SMS sending failed";
      break;
    default: //默认
      self.feedbackMsg.text = @"Result: SMS not sent";
      break;
  }
  
  [self dismissViewControllerAnimated:YES completion:NULL];
}