iphone - 在我的应用程序中包含电子邮件应用程序时出现问题

Question

按下按钮时，将显示 MFMailComposeViewController。

到目前为止我已经完成了。

我的问题是:

1. 是否可以禁止按下取消按钮时弹出的操作表？
2. 是否可以将收件人和主题字段设置为不可编辑？
3. 我想将左栏按钮更改为返回。

我怎样才能做到这些？

- (IBAction)questionButtonPressed:(id)sender {
    email = [[MFMailComposeViewController alloc] init];
    email.mailComposeDelegate = self;

    // Subject
    [email setSubject:@"Testing"];

    // Optional Attachments
    NSData *artwork = UIImagePNGRepresentation([UIImage imageNamed:@"albumart.png"]);
    [email addAttachmentData:artwork mimeType:@"image/png" fileName:@"albumart.png"];

    // Body
    //[email setMessageBody:@"This is the body"];

    // Present it
    [self presentModalViewController:email animated:YES];
}

Answer 1

是的，这三个都是可能的，但是#2 要么需要使用私有(private) API 要么需要一些黑客技术。我采用了子类化 MFMailComposeViewController 的方法，如下

// file: CustomMailComposeViewController.h
@interface CustomMailComposeViewController : MFMailComposeViewController {

}
@end

// file ustomMailComposeViewController.m
#import "CustomMailComposeViewController.h"
@implementation CustomMailComposeViewController

-(void)viewWillAppear:(BOOL)animated {
  [super viewWillAppear:animated];

  //Here we replace the cancel button with a back button (Question #3)
  UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStylePlain target:self action:@selector(backButtonPressed:)];
  self.navigationBar.topItem.leftBarButtonItem  = backButton;
  [backButton release];


  //Here we disallow the user to change to to: cc: bcc: and subject: feilds (Question #2)
  //Warning: the xxxField methods are undocumented private methods. 
  UITableViewController *vc = [self.viewControllers objectAtIndex:0];
  UITableView *tvv = [vc view];
  [[tvv toField] setUserInteractionEnabled:NO];
  [[tvv ccField] setUserInteractionEnabled:NO];
  [[tvv bccField] setUserInteractionEnabled:NO];
  [[tvv multiField] setUserInteractionEnabled:NO];
  [[tvv subjectField] setUserInteractionEnabled:NO];
}


//This is the target for the back button, to immeditally dismiss the VC without an action sheet (#1)
-(void) backButtonPressed:(id)sender {
  [self dismissModalViewControllerAnimated:YES]; 
}
@end

要在代码中使用，您需要更改:[[MFMailComposeViewController alloc] init];到 [[CustomMailComposeViewController alloc] init];