发邮件

1.openURL
使用openURL调用系统邮箱客户端是我们在IOS3.0以下实现发邮件功能的主要手段。我们可以通过设置url里的相关参数来指定邮件的内容，不过其缺点很明显，这样的过程会导致程序暂时退出。下面是使用openURL来发邮件的一个小例子：

    #pragma mark - 使用系统邮件客户端发送邮件   
    -(void)launchMailApp   
    {     
        NSMutableString *mailUrl = [[[NSMutableString alloc]init]autorelease];   
        //添加收件人   
        NSArray *toRecipients = [NSArray arrayWithObject: @"first@example.com"];   
        [mailUrl appendFormat:@"mailto:%@", [toRecipients componentsJoinedByString:@","]];   
        //添加抄送   
        NSArray *ccRecipients = [NSArray arrayWithObjects:@"second@example.com", @"third@example.com", nil];     
        [mailUrl appendFormat:@"?cc=%@", [ccRecipients componentsJoinedByString:@","]];   
        //添加密送   
        NSArray *bccRecipients = [NSArray arrayWithObjects:@"fourth@example.com", nil];     
        [mailUrl appendFormat:@"&bcc=%@", [bccRecipients componentsJoinedByString:@","]];   
        //添加主题   
        [mailUrl appendString:@"&subject=my email"];   
        //添加邮件内容   
        [mailUrl appendString:@"&body=<b>email</b> body!"];   
        NSString* email = [mailUrl stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding];     
        [[UIApplication sharedApplication] openURL: [NSURL URLWithString:email]];     
    }  

 
2.MFMailComposeViewController
MFMailComposeViewController是在IOS3.0新增的一个接口，它在MessageUI.framework中。通过调用MFMailComposeViewController，可以把邮件发送窗口集成到我们的应用里，发送邮件就不需要退出程序了。MFMailComposeViewController的使用方法：

    1.项目中引入MessageUI.framework；
    2.在使用的文件中导入MFMailComposeViewController.h头文件；
    3.实现MFMailComposeViewControllerDelegate，处理邮件发送事件；
    4.调出邮件发送窗口前先使用MFMailComposeViewController里的“+ (BOOL)canSendMail”方法检查用户是否设置了邮件账户；
    5.初始化MFMailComposeViewController，构造邮件体

 

    //   
    //  ViewController.h   
    //  MailDemo   
    //   
    //  Created by LUOYL on 12-4-4.   
    //  Copyright (c) 2012年 http://luoyl.info. All rights reserved.   
    //   
      
    #import <UIKit/UIKit.h>   
    #import <MessageUI/MFMailComposeViewController.h>   
      
    @interface ViewController : UIViewController<MFMailComposeViewControllerDelegate>   
      
    @end  

 

    #pragma mark - 在应用内发送邮件   
    //激活邮件功能   
    - (void)sendMailInApp   
    {   
        Class mailClass = (NSClassFromString(@"MFMailComposeViewController"));    
        if (!mailClass) {   
            [self alertWithMessage:@"当前系统版本不支持应用内发送邮件功能，您可以使用mailto方法代替"];   
            return;   
        }   
        if (![mailClass canSendMail]) {   
            [self alertWithMessage:@"用户没有设置邮件账户"];   
            return;   
        }   
        [self displayMailPicker];   
    }   
      
    //调出邮件发送窗口   
    - (void)displayMailPicker   
    {   
        MFMailComposeViewController *mailPicker = [[MFMailComposeViewController alloc] init];     
        mailPicker.mailComposeDelegate = self;     
           
        //设置主题     
        [mailPicker setSubject: @"eMail主题"];     
        //添加收件人   
        NSArray *toRecipients = [NSArray arrayWithObject: @"first@example.com"];   
        [mailPicker setToRecipients: toRecipients];     
        //添加抄送   
        NSArray *ccRecipients = [NSArray arrayWithObjects:@"second@example.com", @"third@example.com", nil];     
        [mailPicker setCcRecipients:ccRecipients];         
        //添加密送   
        NSArray *bccRecipients = [NSArray arrayWithObjects:@"fourth@example.com", nil];     
        [mailPicker setBccRecipients:bccRecipients];     
           
        // 添加一张图片     
        UIImage *addPic = [UIImage imageNamed: @"Icon@2x.png"];     
        NSData *imageData = UIImagePNGRepresentation(addPic);            // png        
        //关于mimeType：http://www.iana.org/assignments/media-types/index.html   
        [mailPicker addAttachmentData: imageData mimeType: @"" fileName: @"Icon.png"];     
        
        //添加一个pdf附件   
        NSString *file = [self fullBundlePathFromRelativePath:@"高质量C++编程指南.pdf"];   
        NSData *pdf = [NSData dataWithContentsOfFile:file];   
        [mailPicker addAttachmentData: pdf mimeType: @"" fileName: @"高质量C++编程指南.pdf"];     
      
        NSString *emailBody = @"<font color='red'>eMail</font> 正文";     
        [mailPicker setMessageBody:emailBody isHTML:YES];     
        [self presentModalViewController: mailPicker animated:YES];     
        [mailPicker release];     
    }   
      
    #pragma mark - 实现 MFMailComposeViewControllerDelegate    
    - (void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error   
    {   
        //关闭邮件发送窗口   
        [self dismissModalViewControllerAnimated:YES];   
        NSString *msg;     
        switch (result) {     
            case MFMailComposeResultCancelled:     
                msg = @"用户取消编辑邮件";     
                break;     
            case MFMailComposeResultSaved:     
                msg = @"用户成功保存邮件";     
                break;     
            case MFMailComposeResultSent:     
                msg = @"用户点击发送，将邮件放到队列中，还没发送";     
                break;     
            case MFMailComposeResultFailed:     
                msg = @"用户试图保存或者发送邮件失败";     
                break;     
            default:     
                msg = @"";   
                break;     
        }     
        [self alertWithMessage:msg];   
    }