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

//使用名称和数字调用方法。

-(void)openMessageViewWithName:(NSString*)contactName withPhone:(NSString *)phone{

CTTelephonyNetworkInfo *networkInfo=[[CTTelephonyNetworkInfo alloc]init];

CTCarrier *carrier=networkInfo.subscriberCellularProvider;

NSString *Countrycode = carrier.isoCountryCode;

if ([Countrycode length]>0)     //Check If Sim Inserted
{

    [self sendSMS:msg recipientList:[NSMutableArray arrayWithObject:phone]];
}
else
{

    [AlertHelper showAlert:@"Message" withMessage:@"No sim card inserted"];
}

}

//发送消息的方法

- (void)sendSMS:(NSString *)bodyOfMessage recipientList:(NSMutableArray *)recipients{  
 MFMessageComposeViewController *controller1 = [[MFMessageComposeViewController alloc] init] ;
 controller1 = [[MFMessageComposeViewController alloc] init] ;
 if([MFMessageComposeViewController canSendText])
{
    controller1.body = bodyOfMessage;
    controller1.recipients = recipients;
    controller1.messageComposeDelegate = self;
    [self presentViewController:controller1 animated:YES completion:Nil];
 }
}

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

你可以使用这种方法:

[[UIApplication sharedApplication]openURL:[NSURL URLWithString:@"sms:MobileNumber"]]

iOS会自动从你的应用程序导航到消息应用程序的消息合成页面。由于URL的方案是从sms:开始的，这被标识为消息应用程序可以识别的类型，并启动它。

这是一个教程，它完全是你正在寻找的:MFMessageComposeViewController。

http://blog.mugunthkumar.com/coding/iphone-tutorial-how-to-send-in-app-sms/

从本质上讲:

MFMessageComposeViewController *controller = [[[MFMessageComposeViewController alloc] init] autorelease];
if([MFMessageComposeViewController canSendText])
{
    controller.body = @"SMS message here";
    controller.recipients = [NSArray arrayWithObjects:@"1(234)567-8910", nil];
    controller.messageComposeDelegate = self;
    [self presentModalViewController:controller animated:YES];
}

还有文档的链接。

https://developer.apple.com/documentation/messageui/mfmessagecomposeviewcontroller

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