MFMailComposeViewController发送邮件的实例

iPhone API已经提供了系统写邮件界面的接口,使用MFMailComposeViewController，用来显示界面.
项目中需要添加MessageUi.framework。头文件加入MFMailComposeViewControllerDelegate。#import <MessageUI/MessageUI.h>
sendMailViewController.m文件的实现：
- (void)viewDidLoad
{
    UIButton *button = [UIButton buttonWithType: UIButtonTypeRoundedRect];
    button.frame = CGRectMake(0, 40, 320, 50);
    [button setTitle: @"Mail" forState: UIControlStateNormal];
    [button addTarget: self action: @selector(sendEMail) forControlEvents: UIControlEventTouchUpInside];
    [self.view addSubview: button];
}

- (void) alertWithTitle: (NSString *)_title_ msg: (NSString *)msg 
{
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:_title_ 
                                                    message:msg 
                                                   delegate:nil 
                                          cancelButtonTitle:@"确定" 
                                          otherButtonTitles:nil];
    [alert show];
    [alert release];
} 

//点击按钮后，触发这个方法
-(void)sendEMail 
{
    Class mailClass = (NSClassFromString(@"MFMailComposeViewController"));
    
    if (mailClass != nil)
    {
        if ([mailClass canSendMail])
        {
            [self displayComposerSheet];
        } 
        else 
        {
            [self launchMailAppOnDevice];
        }
    } 
    else 
    {
        [self launchMailAppOnDevice];
    }    
}
//可以发送邮件的话
-(void)displayComposerSheet 
{
    MFMailComposeViewController *mailPicker = [[MFMailComposeViewController alloc] init];
    
    mailPicker.mailComposeDelegate = self;
    
    //设置主题
    [mailPicker setSubject: @"eMail主题"];
    
    // 添加发送者
    NSArray *toRecipients = [NSArray arrayWithObject: @"[email protected]"];
    //NSArray *ccRecipients = [NSArray arrayWithObjects:@"[email protected]", @"[email protected]", nil];
    //NSArray *bccRecipients = [NSArray arrayWithObject:@"[email protected]", nil];
    [mailPicker setToRecipients: toRecipients];
    //[picker setCcRecipients:ccRecipients];    
    //[picker setBccRecipients:bccRecipients];
    
    // 添加图片
    UIImage *addPic = [UIImage imageNamed: @"123.jpg"];
    NSData *imageData = UIImagePNGRepresentation(addPic);            // png
    // NSData *imageData = UIImageJPEGRepresentation(addPic, 1);    // jpeg
    [mailPicker addAttachmentData: imageData mimeType: @"" fileName: @"123.jpg"];
    
    NSString *emailBody = @"eMail 正文";
    [mailPicker setMessageBody:emailBody isHTML:YES];
    
    [self presentModalViewController: mailPicker animated:YES];
    [mailPicker release];
}
-(void)launchMailAppOnDevice
{
    NSString *recipients = @"mailto:[email protected]&subject=my email!";
    //@"mailto:[email protected][email protected],[email protected]&subject=my email!";
    NSString *body = @"&body=email body!";
    
    NSString *email = [NSString stringWithFormat:@"%@%@", recipients, body];
    email = [email stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding];
    
    [[UIApplication sharedApplication] openURL: [NSURL URLWithString:email]];
}
- (void)mailComposeController:(MFMailComposeViewController *)controller 
          didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error 
{
    NSString *msg;
    
    switch (result) 
    {
        case MFMailComposeResultCancelled:
            msg = @"邮件发送取消";
            break;
        case MFMailComposeResultSaved:
            msg = @"邮件保存成功";
            [self alertWithTitle:nil msg:msg];
            break;
        case MFMailComposeResultSent:
            msg = @"邮件发送成功";
            [self alertWithTitle:nil msg:msg];
            break;
        case MFMailComposeResultFailed:
            msg = @"邮件发送失败";
            [self alertWithTitle:nil msg:msg];
            break;
        default:
            break;
    }
    
    [self dismissModalViewControllerAnimated:YES];
}