Question

我正在开展一个由多个部分组成的大型项目，每个部分都有不同数量的幻灯片。

我正在尝试动态创建一个导航栏，其中按钮的数量与加载的部分的幻灯片相对应。我遇到的问题是在每张幻灯片加载时设置按钮的开/关外观。

创建部分时创建导航栏，每个幻灯片加载时应更新每个按钮的外观。我正在尝试使用viewWithTag定位每个按钮。当部分的第一张幻灯片加载时外观很好，但是当我点击下一个按钮时，一切都消失了。奇怪的是，当点击回到第一张幻灯片时，一切都会显示出来。

加载某个部分时，会创建一个包含必要幻灯片信息的可变字典对象数组。我有一个从主视图调用的类方法（- (void) newbutton:(NSString *) title withIndex:(int) index atPosition:(int) Xpos），它通过for循环创建一个自定义的“ON”和“OFF”按钮，从plist文件传递title和index参数。之后，加载索引0处的幻灯片。

主视图

- (void) findStory:(NSString *) presentation
{

    [model loadStory:presentation];

    int storyCount = model.currentStory.count;
    if (storyCount > 1) {
        int distribution = 700 / (storyCount - 1); // 700 = width of Navigation Rule
        int Xpos = 89; // 89 = X position of Navigation Rule

        // Build Navidation trail
        for (int i = 0; i < model.currentStory.count; i++) {

            NSLog(@"findStory(): Item Title: %@", [model.currentStory[i] objectForKey:@"name"]);

            [nav newbutton:[model.currentStory[i] objectForKey:@"name"] withIndex:i atPosition:Xpos];
            navButton = nav.button;
            navDot = nav.buttonDot;
            [self.navHolder addSubview:navDot];
            [self.navHolder addSubview:navButton];
            Xpos += distribution;
        }
    }

    [self newPage:model.pageIndex];
}

- (void)newPage:(int) index
{
    NSLog(@"newPage(): Requested page Index is %i", model.pageIndex);
    // Code that finds and loads the slide  

    // At the end the navigation appearance is set
    [self setNavAppearance:index];
}

- (void) setNavAppearance:(int) index
{
    NSLog(@"setNavAppearance(): Setting navigation appearance...");
    int storyCount = model.currentStory.count;

    if (storyCount > 1) {
        for (int i = 0; i < storyCount; i++) {
            int pressedIndex = i + 20;
            int viewTag = i;
            UIButton *onButton = (UIButton *)[self.navHolder viewWithTag:viewTag];
            if (i != index) {
                onButton.hidden = YES;
            } else {
                onButton.hidden = NO;
            }

            UIButton *offButton = (UIButton *)[self.navHolder viewWithTag:pressedIndex];
            offButton.hidden = NO;

        }
    }

    NSLog(@"setNavAppearance(): navigation appearance set.");
}

nav类方法

- (void) newbutton:(NSString *) title withIndex:(int) index atPosition:(int) Xpos
{
    buttonIndex = index;

    button = [[UIButton alloc] init];

    int labelXPosition = (Xpos - 75);
    int dotXposition = (Xpos - 10);

    // ON Button
    buttonLabel = [[UILabel alloc] initWithFrame:CGRectMake(labelXPosition, 637, 150, 55)];
    buttonLabel.textColor = [UIColor blackColor];
    buttonLabel.font = [UIFont fontWithName:@"HelveticaNeue-CondensedBold" size:12];
    buttonLabel.textAlignment = NSTextAlignmentCenter;
    buttonLabel.lineBreakMode = NSLineBreakByWordWrapping;
    buttonLabel.numberOfLines = 2;
    buttonLabel.text = title;
    buttonLabel.backgroundColor = [UIColor clearColor];
    buttonLabel.textColor = [UIColor colorWithRed:0.047f green:0.337f blue:0.494f alpha:1.0f];
    [self.button addSubview:buttonLabel];

    dot = [[UIImageView alloc] initWithFrame:CGRectMake(dotXposition, 702, 20, 20)];
    [dot setImage:[UIImage imageNamed:@"buttonPressed.png"]];
    [self.button addSubview:dot];

    button.tag = buttonIndex;

    // OFF Button
    buttonDot = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    buttonDot.frame = CGRectMake(dotXposition, 702, 20, 20);
    buttonDot.backgroundColor = [UIColor clearColor];
    UIImage *dotImage = [UIImage imageNamed:@"button.png"];
    [buttonDot setBackgroundImage:dotImage forState:UIControlStateNormal];
    UIImage *dotImagePress = [UIImage imageNamed:@"buttonPressed"];
    [buttonDot setBackgroundImage:dotImagePress forState:UIControlStateHighlighted];

    int dotIndex = buttonIndex + 20;
    buttonDot.tag = dotIndex;

}

我不确定发生了什么。每次加载新页面时都会运行-(void) setNavAppearance方法，理论上应该设置所需的外观。

我很感激任何人都可以提供帮助。

由于

Answer 1

正如我的评论中所述;

使用标记设置为0时要小心。如果没有明确定义标记，则使用零。因此，任何没有定义标签的东西都会匹配零。

Xcode：使用viewWithTag定位动态创建的按钮时出现问题

1 个答案: