NSError不會清除舊的錯誤

Question

長時間的聽衆，第一次打電話給我，如果我不夠明確，請原諒我。我目前正在用NSError對象來解決問題。這是怎麼回事兒設置：

-(void)mainMethod { 
    NSError *myError = nil; 
    NSString *myString = @"A really great string. 1234."; 
    if ([self parseAndStoreString:myString error:&myError] == NO) { 
     [self popupWithErrorMessage:[[myError localizedDescription] copy]]; 
    } 

-(BOOL)parseAndStoreString:(NSString *)incomingString error:(NSError *__autoreleasing *)err { 
    if ([self setupSomething error:err] == NO) { 
     return NO; 
    } 
    if ([self doSomethingWithString:incomingString error:err] == NO) { 
     return NO; 
    } 
    if ([self storeString:incomingString error:err] == NO) { 
     return NO; 
    } 
} 

-(BOOL)doSomethingWithString:(NSString *)incomingString error:(NSError *__autoreleasing *)err { 
    if (incomingString == nil) { 
    DLog(@"String was null! See? : %@", incomingString); 
    NSDictionary *errorInfo = [NSDictionary dictionaryWithObject:EDEmptyStringErrorDescription forKey:NSLocalizedDescriptionKey]; 
    if (err != nil) *err = [NSError errorWithDomain:EDStringDomain code:EDEmptyStringError userInfo:errorInfo]; 
    return NO; 
    } 
    if (somethingElseIsWrongWithString) { 
    DLog(@"Another Problem Geesh"); 
    NSDictionary *errorInfo = [NSDictionary dictionaryWithObject:EDAnotherStringErrorDescription forKey:NSLocalizedDescriptionKey]; 
    if (err != nil) *err = [NSError errorWithDomain:EDStringDomain code:EDAnotherStringError userInfo:errorInfo]; 
    return NO; 
    } 
} 

現在哪個錯誤命中通過預計在第一時間被適當建立並顯示在彈出。當用戶點擊某個可再次激活'mainMethod'的方法或調用'parseAndStoreString:error:'（有三個或四個調用方法）的方法時，問題就出現了。如果還有其他錯誤，則彈出窗口顯示第一個錯誤的描述，第二個錯誤粘合到一個字符串中。這是ARC代碼，所以我的理解是編譯器應該在出現錯誤後釋放myError對象（或其他方法創建的任何NSError對象）。我不認爲問題出現在'popupWithErrorMessage'方法中，因爲我只傳入了本地化描述的副本，該副本被顯示並由[popupView orderOut:self]銷燬。有關這些錯誤消息如何在NSError對象中堆積如山的任何想法？

@ torrey.lyons：當然，這裏是togglePopupWithMessage代碼：onView-

- (void)popupWithErrorMessage:(NSString *)errorToDisplay { 
    if (!messagePopup) { 
     if (errorToDisplay == nil) { 
     DLog(@"Warning, incoming error message was nil"); 
     return; 
     } 

     NSDictionary *messageAttributes = [NSDictionary dictionaryWithObjectsAndKeys: 
            [NSColor whiteColor], NSForegroundColorAttributeName, 
            [NSFont systemFontOfSize:12], NSFontAttributeName, 
            nil]; 
     NSAttributedString *messageWithAttributes = [[NSAttributedString alloc] 
                initWithString:errorToDisplay 
                attributes:messageAttributes]; 

     NSPoint messagePoint = NSMakePoint(NSMidX([[self.mainSplitView.subviews objectAtIndex:1] frame]), 
             NSMinY([anchorView frame])+4.0f); 
     messagePopup = [[MAAttachedWindow alloc] initWithView:popupView 
              attachedToPoint:messagePoint 
                inWindow:[self window] 
                onSide:MAPositionBottom 
               atDistance:0]; 
     [messagePopup setAlphaValue:0.0f]; 

     NSTextStorage *messageStorage = popupMessage.textStorage; 
     [messageStorage beginEditing]; 
     [messageStorage insertAttributedString:messageWithAttributes atIndex:0]; 
     [messageStorage endEditing]; 

     [messagePopup setFrame:NSMakeRect(messagePopup.frame.origin.x, messagePopup.frame.origin.y, 250.0f, 100.0f) 
        display:YES]; 

     messageWithAttributes = nil; 
     messageAttributes = nil; 
     errorToDisplay = @""; 

     [[self window] addChildWindow:messagePopup ordered:NSWindowAbove]; 


     [[messagePopup animator] setAlphaValue:1.0f]; 
     [popupMessage setNeedsDisplay:YES]; 

     [NSTimer scheduledTimerWithTimeInterval:3.5 
             target:self 
            selector:@selector(turnOffPopupFromTimer:) 
            userInfo:nil 
             repeats:NO]; 
    } else { 
     [[self window] removeChildWindow:messagePopup]; 
     [messagePopup fadeOutAndOrderOut:YES]; 
     messagePopup = nil; 
    } 
- (void)turnOffPopupFromTimer:(NSTimer *)timer { 
    if (messagePopup) {    
            //Added to correct problem \/\/\/\/ 
     NSTextStorage *messageStorage = popupMessage.textStorage; 
     [messageStorage beginEditing]; 
     [messageStorage deleteCharactersInRange:NSMakeRange(0, messageStorage.characters.count)]; 
     [messageStorage endEditing]; 
            //Added to correct problem /\/\/\/\ 
     [[self window] removeChildWindow:messagePopup]; 
     [messagePopup fadeOutAndOrderOut:YES]; 
     messagePopup = nil; 
    } 
} 

Answer 1

我懷疑問題出在popupWithErrorMessage，這是堆放本地化描述。即使NSError對象的生命週期中存在一個錯誤，爲每個錯誤創建的每個錯誤都是一個單獨的對象，並且不會有其他NSError對象的本地化描述。另一方面，您對popupWithErrorMessage的描述聽起來很可疑：[popupView orderOut:self]只是將窗口從屏幕上移除，但不會釋放它或導致它被破壞。你能發佈popupWithErrorMessage的代碼嗎？