分段控件中的 NSArray 问题

本文介绍了分段控件中的 NSArray 问题的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我使用这个示例来创建分段视图.在我的 viewDidLoad 方法中，我收到警告和代码崩溃.

I used this example to create a segmented view. In my viewDidLoad method I am getting a warning and code crashes.

- (void)viewDidLoad { [super viewDidLoad]; self.segmentedViewControllers = [self segmentedViewControllerContent]; NSArray * segmentTitles = [self.segmentedViewControllers arrayByPerformingSelector:@selector(title)]; self.segmentedControl = [[UISegmentedControl alloc] initWithItems:segmentTitles]; self.segmentedControl.selectedSegmentIndex = 0; self.segmentedControl.segmentedControlStyle = UISegmentedControlStyleBar; [self.segmentedControl addTarget:self action:@selector(didChangeSegmentControl:) forControlEvents:UIControlEventValueChanged]; self.navigationItem.titleView = self.segmentedControl; [self.segmentedControl release]; [self didChangeSegmentControl:self.segmentedControl]; }

我在这一行收到警告:

NSArray * segmentTitles = [self.segmentedViewControllers arrayByPerformingSelector:@selector(title)];

NSArray 可能不会响应 arrayByPerformingSelector.

推荐答案

arrayByPerformingSelector: 不是要发送到 NSArray 的有效消息.这个方法很可能在原代码使用的NSArray的类别扩展之一中.检查您所遵循的原始示例并尝试找到 arrayByPerformingSelector: 的定义位置，然后在您的代码中找到该文件的 #import.

arrayByPerformingSelector: is not a valid message to be sent to NSArray. This method is probably in one of the category extensions of NSArray that the original code uses. Check the original example you are following and try to find where arrayByPerformingSelector: is defined, then #import that file in your code.