iphone：如何在iPhone Ebook App中添加电子邮件功能

这是代码：

- (IBAction) sendEmail:(id)sender
{
    Class mailClass = (NSClassFromString(@"MFMailComposeViewController"));
if (mailClass != nil)
{
    // We must always check whether the current device is configured for sending emails
    if ([mailClass canSendMail])
    {
        [self displayComposerSheet];
    }
    else
    {
        [self launchMailAppOnDevice];
    }
}
else
{
    [self launchMailAppOnDevice];
}
}

-(void)displayComposerSheet 
{
    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
    picker.mailComposeDelegate = self;

    [picker setSubject:@"Hello from DShah!"];

    NSArray *toRecipients = [NSArray arrayWithObject:@"first@example.com"]; 
    NSArray *ccRecipients = [NSArray arrayWithObjects:@"second@example.com",@"third@example.com",nil]; 
    NSArray *bccRecipients = [NSArray arrayWithObject:@"fourth@example.com"]; 

    [picker setToRecipients:toRecipients];
    [picker setCcRecipients:ccRecipients];  
    [picker setBccRecipients:bccRecipients];

    NSString *path = [[NSBundle mainBundle] pathForResource:@"userdata" ofType:@"abc"];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *fullPath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.abc",@"userdata"]]; 
    NSData *myData = [NSData dataWithContentsOfFile:fullPath];
    [picker addAttachmentData:myData mimeType:@"csv" fileName:@"userdata.abc"];

    NSString *emailBody = @"It is raining in sunny California!";
    [picker setMessageBody:emailBody isHTML:NO];

    [self presentModalViewController:picker animated:YES];
    [picker release];
}

-(void)launchMailAppOnDevice
{
    NSString *recipients = @"mailto:first@example.com&subject=Hello from DShah!";
    NSString *body = @"&body=It is cold in Winter!";

    NSString *email = [NSString stringWithFormat:@"%@%@",recipients,body];
    email = [email stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:email]];
}

然后实现Delegate方法如下….

- (void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error 
{
    switch (result)
    {
        case MFMailComposeResultCancelled:
            message = @"Result: canceled";
            break;
        case MFMailComposeResultSaved:
            message = @"Result: saved";
            break;
        case MFMailComposeResultSent:
            message = @"Result: sent";
            break;
        case MFMailComposeResultFailed:
            message = @"Result: failed";
            break;
        default:
            message = @"Result: not sent";
            break;
    }

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Email Demo" message:message delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil,nil];
    [alert show];
    [alert release];

    [self dismissModalViewControllerAnimated:YES];
}