Question

所以，StackOverflow上的另一个EXC_BAD_ACCESS主题，但由于我是Objective-C的新手，这仍然是我还没有真正掌握的主题。尽管我已经做了很多关于它的研究。

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

所以我声明了一个调用UITapGestureRecognizer方法的openMultiSelect:。但是在[parent.navigationController pushViewController:view animated:YES];行上我收到Program received signal: "EXC_BAD_ACCESS".错误。为什么？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。有一个更好的方法吗？因为现在我有一个包含Tabs的ViewController。在activateTab:方法中，我创建了标签并传递self。我在该标签的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。这样的事情：

- (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

你做错了是过早发布对象“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];

如何摆脱EXC_BAD_ACCESS

2 个答案: