按"Delete Draft“时MFMailComposeViewController崩溃

Question

我有一个可以调用MFMailComposeViewController的按钮。有时，当我点击“删除草稿”时，应用程序会崩溃，但有时它会正确地忽略视图。我不明白为什么。下面是我的代码：

- (IBAction)openEmail:(id)sender {
if ([MFMailComposeViewController canSendMail]) {
    MFMailComposeViewController *composer = [[MFMailComposeViewController alloc] init];
    composer.mailComposeDelegate = (id)self;
    NSArray *myEmail = [[NSArray alloc] initWithObjects:@"me@gmail.com", nil];
    [composer setToRecipients:myEmail];
    [self presentViewController:composer animated:YES completion:nil];
    [[composer navigationBar] setTintColor:[UIColor colorWithRed:0.843 green:0.435 blue:0.435 alpha:1]];
}
else {

   }
}

这个方法是：

- (void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError*)error {
switch (result)
{
    case MFMailComposeResultCancelled:
        NSLog(@"Mail cancelled");

        break;
    case MFMailComposeResultSaved:
        NSLog(@"Mail saved");

        break;
    case MFMailComposeResultSent:
        NSLog(@"Mail send");

        break;
    case MFMailComposeResultFailed:
        NSLog(@"Mail failed");

        break;
    default:
        NSLog(@"Mail not sent.");

        break;
}
[self dismissViewControllerAnimated:YES completion:nil];
}

有谁可以帮我？

Answer 1

我以前也遇到过这种情况，代码中的潜在问题可能是下面这一行：

MFMailComposeViewController *composer = [[MFMailComposeViewController alloc] init];

很可能在调用MFMailComposeViewControllerDelegate方法时，您的composer对象已被释放。相反，可以尝试在强属性上初始化MFMailComposeViewController，如下所示：

self.composer = [MFMailComposeViewController new];

一旦对委托方法执行了操作以释放MFMailComposeViewController，就可以将self.composer设置为nil。

Answer 2

您是否尝试过：

[self presentModalViewController:_picker animated:YES];

注意到'MODAL‘了吗？

此外，还有：

[self dismissModalViewControllerAnimated:YES];