自定義UIStoryboardPopoverSegue不會在iOS 5.1下工作

Question

我已經實現了一個自定義的故事板segue，它在iOS 6下工作正常，但在iOS 5.1下的模擬器中沒有任何反應。 問題是popoverController在iOS 5.1下始終爲零？

@implementation PopoverFromRectSegue 

-(id)initWithIdentifier:(NSString *)identifier 
      source:(UIViewController *)source 
     destination:(UIViewController *)destination { 

    if(self = [super initWithIdentifier:identifier 
          source:source 
         destination:destination]) { 
    } 

    return self; 
} 

- (void)perform { 
    UIPopoverController *popCtrl = ((UIStoryboardPopoverSegue *)self).popoverController; 

    id controller = [self sourceViewController]; 
    if ([controller isKindOfClass:[UIViewController class]] && [controller respondsToSelector:@selector(popoverRect)]) { 
    [popCtrl presentPopoverFromRect:[[controller performSelector:@selector(popoverRect)] CGRectValue] inView:[controller view] permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES]; 
    } 
} 
@end 

任何幫助/提示表示讚賞。

編輯： 剛做了一個新的示例項目。看起來在iOS5.1下，popoverController沒有爲自定義UIStoryBoardSegues設置爲 。 我還能做什麼。 正常的彈出窗口需要一個錨點，但原型tableView單元格不被接受（編譯期間失敗），我無法找到修改彈出窗口顯示的矩形的方法。

Answer 1

這是我的解決方法。
PopoverFromRectSegue.h

@interface PopoverFromRectSegue : UIStoryboardPopoverSegue 
    @property (strong, nonatomic) UIPopoverController *popoverCtrl; 
@end 

PopoverRectFromSegue.m

#import "PopoverFromRectSegue.h" 
@implementation PopoverFromRectSegue 

- (void)perform 
{ 
    UIPopoverController *popCtrl = ((UIStoryboardPopoverSegue *)self).popoverController; 

    // under iOS 5.1 the popoverController iVar is not set 
    // so we have to use our own one 
    if (nil == popCtrl) { 
    popCtrl = self.popoverCtrl; 
    } 

    id controller = [self sourceViewController]; 
    if ([controller isKindOfClass:[UIViewController class]] && [controller respondsToSelector:@selector(popoverRect)]) { 
    [popCtrl presentPopoverFromRect:[[controller performSelector:@selector(popoverRect)] CGRectValue] inView:[controller view] permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES]; 
    } 
} 

@end 

在我prepareForSegue方法我做到以下幾點。

if (isPad) { 
     self.popoverCtrl = [(UIStoryboardPopoverSegue *)segue popoverController]; 
     if (nil == _popoverCtrl) { 
     self.popoverCtrl = [[UIPopoverController alloc] initWithContentViewController:[segue destinationViewController]]; 
     ((PopoverFromRectSegue *)segue).popoverCtrl = _popoverCtrl; 
     } 
     self.popoverRect = [NSValue valueWithCGRect:[self.myTableView rectForRowAtIndexPath:indexPath]]; 
    }