iOS 4中有一个类支持从应用程序中发送带有正文和收件人的消息。它的工作原理与发送邮件相同。你可以在这里找到文档:链接文本

遵循以下步骤

1 .添加消息i。项目框架

2。在.h文件中导入# Import <MessageUI/MessageUI.h>。

3.复制此代码以发送消息

 if ([MFMessageComposeViewController canSendText]) {
    MFMessageComposeViewController *messageComposer =
    [[MFMessageComposeViewController alloc] init];
    NSString *message = @"Message!!!";
    [messageComposer setBody:message];
    messageComposer.messageComposeDelegate = self;
    [self presentViewController:messageComposer animated:YES completion:nil];
}

4所示。实现委托方法，如果你想。

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


   ///your stuff here 

    [self dismissViewControllerAnimated:YES completion:nil];
}

快跑!

如果你想在你自己的应用程序中显示创建和发送消息，你需要使用MFMessageComposeViewController。

否则，您可以使用sharedApplication方法。

//Add the Framework in .h file

#import <MessageUI/MessageUI.h>
#import <MessageUI/MFMailComposeViewController.h>

//Set the delegate methods

UIViewController<UINavigationControllerDelegate,MFMessageComposeViewControllerDelegate>

//add the below code in .m file


- (void)viewDidAppear:(BOOL)animated{
    [super viewDidAppear:animated];

    MFMessageComposeViewController *controller = 
    [[[MFMessageComposeViewController alloc] init] autorelease];

    if([MFMessageComposeViewController canSendText])
    { 
        NSString *str= @"Hello";
        controller.body = str;
        controller.recipients = [NSArray arrayWithObjects:
                                 @"", nil];
        controller.delegate = self;
        [self presentModalViewController:controller animated:YES];  
    }


}

- (void)messageComposeViewController:
(MFMessageComposeViewController *)controller
                 didFinishWithResult:(MessageComposeResult)result 
{
    switch (result)
    {
        case MessageComposeResultCancelled:  
            NSLog(@"Cancelled");    
            break; 
        case MessageComposeResultFailed:
            NSLog(@"Failed");
            break;   
        case MessageComposeResultSent:      
            break; 
        default:  
            break;  
    }  
    [self dismissModalViewControllerAnimated:YES]; 
}

你可以展示MFMessageComposeViewController，它可以发送短信，但是有用户提示(他点击发送按钮)。没有用户许可，不可能这样做。在iOS 11上，你可以做扩展，就像传入消息的过滤器，告诉iOS它是不是垃圾邮件。没有什么是短信不能做的

- (void)sendSMS:(NSString *)bodyOfMessage recipientList:(NSArray *)recipients
{
    UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
    UIImage *ui =resultimg.image;
    pasteboard.image = ui;
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"sms:"]];
}