changing the MFMailComposeViewController navigationBar title font

问题

I have a MFMailComposeViewController and when I've set the subject it also sets it as the subject. The question is how do I customize the font of the title and color?

MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
[picker setSubject:@"Feedback for MyApp"];

回答1:

i've changed the font generally for my apps from the app-delegate for all navigation bars of all view controllers. if you don't mind it changing all of your navigation bar title fonts, put something like the following in applicationDidFinishLaunching:withOptions:

    if ([[UINavigationBar class] respondsToSelector:@selector(appearance)])
        // set the navigation bar font to "courier-new bold 14"
        [[UINavigationBar appearance] setTitleTextAttributes:
         [NSDictionary dictionaryWithObjectsAndKeys:[UIColor lightGrayColor], UITextAttributeTextShadowColor,
                                                    [NSValue valueWithUIOffset:UIOffsetMake(1, 0)], UITextAttributeTextShadowOffset,
                                                    [UIFont fontWithName:@"CourierNewPS-BoldMT" size:14.0], UITextAttributeFont, 
                                                    nil]];

update: if you want it specific to this one case, you can probably use appearanceWhenContainedIn: using the arguments Alexander Akers suggested in the comment below, since UIViewController inherits from UIAppearanceContainer. i know appearanceWhenContainedIn: works in other cases such as UIBarButtonItems contained in UINavigationBar, so it should work similarly for this situation.

回答2:

My guess is it can't be done because of cross-process restrictions. I can change the color, size, and font (if it's a built-in system font), but attempts to change it to any of the fonts included in my app fail.

回答3:

Since the MFMailComposeViewController is an instance of a UINavigationController, you can set the titleView of its topViewController as follows:

UIViewController *controller = [mailController topViewController];

UIView *titleView = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 170.0f, 44.0f)];
titleView.backgroundColor = [UIColor clearColor];

UILabel *label = [[UILabel alloc] initWithFrame:titleView.bounds];
label.textColor = [UIColor whiteColor];
label.backgroundColor = [UIColor clearColor];
label.text = @"Custom Font";
label.font = [UIFont italicSystemFontOfSize:27.0f];
label.textAlignment = UITextAlignmentCenter;

[titleView addSubview:label];
[label release];

controller.navigationItem.titleView = titleView;
[titleView release];

来源：https://stackoverflow.com/questions/11173693/changing-the-mfmailcomposeviewcontroller-navigationbar-title-font