导入头文件

头文件：#import <MessageUI/MessageUI.h>
遵循代理：<MFMessageComposeViewControllerDelegate>

跳转代码实现

//是否可以发送文本消息（模拟器不可以）
    if ([MFMessageComposeViewController canSendText]) {
        MFMessageComposeViewController *vc = [[MFMessageComposeViewController alloc]init];
        vc.recipients = @[phoneNum];//短信接收者---是个数组
        vc.body = @"";//短信内容
        vc.messageComposeDelegate = self;
        [self presentViewController:vc animated:YES completion:nil];
    }else {
        NSLog(@"设备不支持发送短信");
    }

代理方法实现

#pragma mark-   ======   MFMessageComposeViewControllerDelegate   =======
- (void)messageComposeViewController:(MFMessageComposeViewController *)controller didFinishWithResult:(MessageComposeResult)result
{
    //发送完信息就回到程序
    [self dismissViewControllerAnimated:YES completion:nil];
    switch (result) {
        case MessageComposeResultSent:
            [HUD showHUDMessage:@"发送成功"];
            break;
        case MessageComposeResultFailed:
            [HUD showHUDMessage:@"发送失败"];
            break;
        case MessageComposeResultCancelled:
            [HUD showHUDMessage:@"取消发送"];
            break;
        default:
            break;
    }
}

在 demo 中这样写，是可以，但是放到有些项目中短信界面的导航栏一片空白，没有取消按钮，无法返回自己的应用，出现这种情况看看自己的项目中是不是用了UINavigationController+FDFullscreenPopGesture这个第三方全屏滑动返回，如果用了的话在下面这个方法中添加一段代码：

- (void)fd_pushViewController:(UIViewController *)viewController animated:(BOOL)animated

就像这样子，到这里已经大功告成

- (void)fd_pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if ([self isKindOfClass:NSClassFromString(@"MFMessageComposeViewController")]) {
        [self fd_pushViewController:viewController animated:animated];
        return;
    }
}