objective-c - 更改 UISegmentedControl selectedSegmentIndex 不会更改所选索引

Question

我正在尝试使用 UISegmentControl 在 iOS5 的导航栏中创建一个切换按钮。我遇到的问题是 setSelectedSegmentIndex 不是持久的，即当用户单击其中一个段时，它的操作被调用但它没有设置为选中。我当前的代码如下所示:

// In viewDidLoad
toolSegment = [[UISegmentedControl alloc] initWithItems:
                                        [NSArray arrayWithObjects:
                                         [UIImage imageNamed:@"ToolPenIcon.png"],
                                         [UIImage imageNamed:@"TextIcon.png"],
                                         nil]];
[toolSegment addTarget:self action:@selector(changeMode:) forControlEvents:UIControlEventValueChanged];
toolSegment.frame = CGRectMake(0, 0, 85, 30);
toolSegment.segmentedControlStyle = UISegmentedControlStyleBezeled;
toolSegment.momentary = YES;    
[toolSegment setSelectedSegmentIndex:1];    
UIBarButtonItem *segmentBarItem = [[UIBarButtonItem alloc] initWithCustomView:toolSegment];
self.navigationItem.rightBarButtonItem = segmentBarItem;

self.navigationController.navigationBar.tintColor = [UIColor blackColor];   

- (void)changeMode:(id)sender
{    
    UISegmentedControl * control = (UISegmentedControl*)sender;

    if (control.selectedSegmentIndex == 0) {
        NSLog(@"Print");
        [toolSegment setSelectedSegmentIndex:0];    
    } else {
         // Should change the selected index.             
         [toolSegment setSelectedSegmentIndex:1];

        [pageView changeToText];
        if (pageView.canvas.image != nil) {
            [self createNewPage];
        }
        writing = YES;
    }    
}

任何关于我可能做错的提示都将不胜感激。

Answer 1

您可能不希望控件处于momentary 模式，因为这将允许进行多项选择。将 momentary 设置为 NO。