iOS iPad UIActionSheet问题

Question

我目前正在开发一个应用程序,它需要一个使用多种服务"共享"的选项; 比如电子邮件,推特.

为此,我有一个UIBarButtonItem编码输入,当触摸时,它会触发:

UIActionSheet *sheet = [[UIActionSheet alloc] 
                            initWithTitle:@""
                            delegate:self
                            cancelButtonTitle:nil
                            destructiveButtonTitle:nil
                            otherButtonTitles:nil];

    [sheet addButtonWithTitle:@"Email"];
    [sheet addButtonWithTitle:@"Tweet"];
    [sheet addButtonWithTitle:@"Cancel"];

    sheet.cancelButtonIndex = sheet.numberOfButtons-1;

    [sheet showFromRect:self.view.bounds inView:self.view animated:YES];
    [sheet release];

与此相结合以检测选择了哪个按钮:

clickedButtonAtIndex:(NSInteger)buttonIndex {
    if (buttonIndex == actionSheet.cancelButtonIndex) { return; }
    switch (buttonIndex) {
        case 0:
        {

            [self emailThis];
            break;
        }
        case 1:
        {
            [self tweetThis];
            break;
        }
    }

这适用于iPhone.但不幸的是它在iPad上显示不正确.看起来它正在尝试显示UIPopoverController,但它位于导航栏的中心,几乎没有高度.

我已经研究过使用UIPopoverController,但我似乎无法找到如何将它与按钮一起使用.无论如何我可以调整上面的代码来正确显示按钮,因为它已经尝试了.

非常感谢,

瑞安

PS:我是Objective-c/iOS编码的新手,所以请具体说明.谢谢 :)

编辑: 我尝试过使用:

[sheet showFromBarButtonItem:[self share] animated:YES];

但它不起作用.这是我的按钮代码:

UIBarButtonItem *share = [[UIBarButtonItem alloc] 
                                initWithTitle:@"Share"                                            
                                style:UIBarButtonItemStyleBordered 
                                target:self 
                                action:@selector(loadShare)];
    self.navigationItem.rightBarButtonItem = share;
    [share release];

这里也是.h文件中的代码:

@interface DetailViewController : UIViewController <UITableViewDelegate, UITableViewDataSource> {
UIBarButtonItem *share;
}

@property (nonatomic, retain) IBOutlet UIBarButtonItem *share;

这是调试错误:

由于未捕获的异常'NSInvalidArgumentException'终止应用程序,原因:' * - [__ NSPlaceholderArray initWithObjects:count:]:尝试从对象[0]中插入nil对象

Answer 1

self.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(actionPhotoShare:)] autorelease];

...

-(void)actionPhotoShare:(id)sender
{
actionSheetShare = [[UIActionSheet alloc] initWithTitle:nil 
                                                              delegate:self 
                                                     cancelButtonTitle:nil
                                                destructiveButtonTitle:NSLocalizedString(@"ActionSheet_Cancel", @"")
                                                     otherButtonTitles:NSLocalizedString(@"ActionSheet_Email", @""),nil];

if (IS_DEVICE_IPAD) {
    [actionSheetShare showFromBarButtonItem:sender animated:YES];
}else {
    [actionSheetShare showInView:self.view];
}
}