如何擺脫EXC_BAD_ACCESS

Question

因此，StackOverflow上的另一個EXC_BAD_ACCESS主題，但由於我是Objective-C的新手，這仍然是我還沒有真正掌握的主題。儘管我已經做了大量的研究。

問題如下。我有一個UIScrollView，我用自定義類覆蓋（名爲MultiSelectView）。如果用戶點擊此UIScrollView，然後我想打開一個允許他選擇一些數據的視圖。

所以我宣佈了一個UITapGestureRecognizer，它調用openMultiSelect:方法。但在線[parent.navigationController pushViewController:view animated:YES];我得到一個Program received signal: "EXC_BAD_ACCESS".錯誤。爲什麼？爲什麼？

- (id) initWithCoder:(NSCoder *) coder { 
    self = [super initWithCoder: coder]; 

    if (self) { 
     // Add a Tap Gesture Recognizer to the Scrollview. 
     // If the user taps the view, it triggers the 'openMultiSelect' method. 
     UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(openMultiSelect:)]; 
     [singleTap setNumberOfTapsRequired:1]; 
     [singleTap setNumberOfTouchesRequired:1]; 
     [self addGestureRecognizer:singleTap]; 
    } 

    return self; 
} 

- (void)openMultiSelect:(UIGestureRecognizer *)gesture { 
    //int myViewTag = gesture.view.tag; // now you know which view called 

    DataSelectView *view = [[DataSelectView alloc] initWithNibName:@"DataSelectView" bundle:[NSBundle mainBundle]]; 
    view.allowMultiSelect = YES; 

    [parent.navigationController pushViewController:view animated:YES]; 
    [view release]; 
} 

因此，您看到的parent是包含該選項卡的ViewController。有一個更好的方法嗎？因爲現在我有一個包含Tabs的ViewController。在我的activateTab:方法中，我創建了選項卡並沿着self傳遞。我做的viewDidLoad同該標籤的parent傳遞到定製UIScrollView：

- (void) activateTab:(int)index { 
    ... code ... 

    self.tab_Basic = [[TabBasic alloc] initWithNibName:@"TabBasic" bundle: [NSBundle mainBundle]]; 
    self.tab_Basic.parent = self; 

    ... code ... 
} 

Answer 1

你在做什麼錯被釋放對象「視圖」太早，直到觀點是不鬆開，彈出。這應該解決問題。

- (void)openMultiSelect:(UIGestureRecognizer *)gesture { 
//int myViewTag = gesture.view.tag; // now you know which view called 

DataSelectView *view = [[DataSelectView alloc] initWithNibName:@"DataSelectView" bundle:[NSBundle mainBundle]]; 
view.allowMultiSelect = YES; 

[parent.navigationController pushViewController:view animated:YES]; 

Answer 2

您應該對您的回調方法進行一些更改。類似的東西：

- (void)openMultiSelect:(UIGestureRecognizer *)gesture { 
    //int myViewTag = gesture.view.tag; // now you know which view called 
    if(gesture.state == UIGestureRecognizerStateEnded){ 
     DataSelectView *view = [[DataSelectView alloc] initWithNibName:@"DataSelectView" bundle:[NSBundle mainBundle]]; 
     view.allowMultiSelect = YES; 

     [parent.navigationController pushViewController:view animated:YES]; 
     [view release]; 
    } 
}