如何摆脱 EXC_BAD_ACCESS

Question

所以，这是 StackOverflow 上的另一个 EXC_BAD_ACCESS 主题，但由于我是 Objective-C 的新手，这仍然是一个我还没有真正掌握的主题。尽管我已经对此做了很多研究。

问题如下。我有一个 UIScrollView，我已使用自定义类（名为 MultiSelectView）覆盖它。如果用户点击这个 UIScrollView 然后我想打开一个允许他选择一些数据的视图。

因此，我声明了一个调用 openMultiSelect: 方法的 UITapGestureRecognizer 。但在 [parent.navigationController PushViewController:viewanimate:YES]; 线上，我收到一个 Program returned signal: "EXC_BAD_ACCESS". 错误。为什么哦为什么？

- (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 是一个包含选项卡的 ViewController。有更好的方法吗？因为现在我有一个包含选项卡的 ViewController。因此，在其 activateTab: 方法中，我创建了选项卡并传递 self 。我在该选项卡的 viewDidLoad 中执行相同操作，将 parent 传递给自定义 UIScrollView：

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

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

   ... code ...
}

Answer 1

您应该对回调方法进行一些更改。像这样的东西：

- (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];
    }
}

Answer 2

你做错的是太早释放对象“视图”，在弹出视图之前不要释放它。这应该可以解决问题。

- (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];