MFMailComposeViewController 加载一个空白的白屏答案

【问题标题】：MFMailComposeViewController loads a blank white screenMFMailComposeViewController 加载一个空白的白屏
【发布时间】：2011-04-26 02:05:29
【问题描述】：

我正在运行 OS 3.1.3 的 iPod Touch 上进行测试

试图让用户从应用程序内发送电子邮件 - 但是当执行以下代码时，整个屏幕变成完全空白/白色。

关于为什么会发生这种情况的任何想法？我在项目中有 MessageUI 框架。我在头文件中导入和委托：

#import <MessageUI/MessageUI.h>
#import <MessageUI/MFMailComposeViewController.h>
<MFMailComposeViewControllerDelegate>

这是代码，非常标准：

if ([MFMailComposeViewController canSendMail]) {
    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
    picker.mailComposeDelegate = self;

    [picker setSubject:@"App Feedback"];
    [picker setToRecipients:[NSArray arrayWithObject:@"xyz@gmail.com"]];

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

然后我有 didFinishWithResult 函数，它会在发送电子邮件时关闭 ModalViewController。

但同样，我得到的只是 iPod Touch 上的空白屏幕。 =/

谢谢！

【问题讨论】：

您为什么使用名称picker 作为邮件控制器？
您可以使用任何您想要的名称 - 您正在创建一个新的 MFMailComposeViewController 并将其命名为 *picker 或 *picklesAndCheese 或任何您想要的名称
哇这个问题已经三年多了。我不再有撰写电子邮件的问题了，但我也不再对 iOS 3.1.3 做任何事情... =)
@RansLearns 当然，但最好将对象命名为与其所属的类相关的名称。例如，mailComposeController 或类似的东西。 Apple 的所有示例代码都使用来自UIViewController 的对象执行此操作。这就是我的意思，显然你可以随心所欲地命名它！
明白了。老实说，当我第一次学习从应用程序中发送电子邮件时，我相信我是从 stackoverflow 中得到它的，并且从那以后的所有年里都不必更改它。在这里似乎很常见：stackoverflow.com/questions/7706673/… 或 stackoverflow.com/questions/6934470/…

标签： iphone email ipod-touch

【解决方案1】：

if([MFMailComposeViewController canSendMail]){

        MFMailComposeViewController *mail=[[MFMailComposeViewController alloc]init];
        mail.mailComposeDelegate=self;
        [mail setSubject:@"App Feedback"];          
        [mail setMessageBody:@"*your message  content*" isHTML:NO];
        [self presentModalViewController:mail animated:YES];
        [mail release];         
    }

- (void)mailComposeController:(MFMailComposeViewController*)mailController didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error {
        [self dismissModalViewControllerAnimated:YES];

}

【讨论】：

【解决方案2】：

您可以查看来自苹果的示例代码： http://developer.apple.com/library/ios/#samplecode/MessageComposer/Listings/Classes_MessageComposerViewController_m.html

-(IBAction)showMailPicker:(id)sender {

Class mailClass = (NSClassFromString(@"MFMailComposeViewController"));

if (mailClass != nil) {
        [self displayMailComposerSheet];

    if ([mailClass canSendMail]) {
        [self displayMailComposerSheet];
    }
    else {
        feedbackMsg.hidden = NO;
        feedbackMsg.text = @"Device not configured to send mail.";
    }
}
else    {
    feedbackMsg.hidden = NO;
    feedbackMsg.text = @"Device not configured to send mail.";
}

}

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

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



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:@"rainy" ofType:@"jpg"];
NSData *myData = [NSData dataWithContentsOfFile:path];
[picker addAttachmentData:myData mimeType:@"image/jpeg" fileName:@"rainy"];


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

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

} - (void)mailComposeController:(MFMailComposeViewController*)控制器 didFinishWithResult:(MFMailComposeResult)结果错误:(NSError*)error {

feedbackMsg.hidden = NO;
// Notifies users about errors associated with the interface
switch (result)
{
    case MFMailComposeResultCancelled:
        feedbackMsg.text = @"Result: Mail sending canceled";
        break;
    case MFMailComposeResultSaved:
        feedbackMsg.text = @"Result: Mail saved";
        break;
    case MFMailComposeResultSent:
        feedbackMsg.text = @"Result: Mail sent";
        break;
    case MFMailComposeResultFailed:
        feedbackMsg.text = @"Result: Mail sending failed";
        break;
    default:
        feedbackMsg.text = @"Result: Mail not sent";
        break;
}
[self dismissModalViewControllerAnimated:YES];

}

【讨论】：