MFMailComposer无法在iPhone 3GS中运行

Question

我有MFMailComposer的这段代码在模拟器和iPhone 4中正常工作，但它在3GS上崩溃了。是什么原因以及解决方法是什么？

我用断点检查了它。 mailPicker未分配内存。

    MFMailComposeViewController *mailPicker = [[MFMailComposeViewController alloc] init];
mailPicker.mailComposeDelegate = self;

// Set the subject of email
[mailPicker setSubject:@"Somebody got place in my sh*t list"];
NSString *emailBody = @"I just added somebody to my s**t list";

// This is not an HTML formatted email
[mailPicker setMessageBody:emailBody isHTML:NO];

// Create NSData object as PNG image data from camera image
NSData *data = UIImagePNGRepresentation([self captureScreen]);

// Attach image data to the email
// 'CameraImage.png' is the file name that will be attached to the email
[mailPicker addAttachmentData:data mimeType:@"image/png" fileName:@"CameraImage"];

// Show email view 
[self presentModalViewController:mailPicker animated:YES];

// Release picker

[mailPicker release];

Answer 1

如果设备上至少启用了一个电子邮件帐户，则以下呼叫应返回YES：

[MFMailComposeViewController canSendMail]

相反，如果所有帐户都被禁用/删除，它将返回NO。