索引iCarousel中UIView的多选

Question

因此，当我单击该视图中的按钮时，我想在 iCarousel 中突出显示特定的UIView，并且我希望能够在轮播中突出显示尽可能多的视图。所以我有一个按钮可以在视图中设置UIImageview 的alpha 我遇到的问题是虽然它知道视图的索引我不知道如何调用UIImageview 的相应索引在那个视图中。所以我在一个自定义笔尖中设置了UIImageview，我用这段代码设置了 iCarousel 的视图：

根据@danh 回答更新

//.h
@property (nonatomic, strong)NSMutableSet *selected;
//.m
- (void)viewDidLoad
 {
 self.selected = [NSMutableSet set];
}

- (UIView *)carousel:(iCarousel *)carousel viewForItemAtIndex:(NSUInteger)index reusingView:(UIView *)view
{

    //create new view if no view is available for recycling
    if (view == nil)
    {
        view = [[[NSBundle mainBundle] loadNibNamed:@"ItemView" owner:self options:nil] lastObject];
}
 int chkTag = checkImg.tag;
checkImg = (UIImageView *)[checkImg viewWithTag:chkTag];

NSNumber *indexNum = [NSNumber numberWithInt:index];
// here's where the view state gets set
checkImg.alpha = ([self.selected member:indexNum])? 1.0 : 0.0;
  return view;
}

然后我在选择特定视图时调用它：

- (void)carouselCurrentItemIndexUpdated:(iCarousel *)carousel1{
    NSInteger indexInt = carousel1.currentItemIndex;
NSNumber *index = [NSNumber numberWithInt:indexInt];
if ([self.selected member:index]) {
    [self.selected removeObject:index];
} else {
    [self.selected addObject:index];
}

// now just reload that item, and let the viewForItemAtIndex
// take care of the selection state
[carousel reloadItemAtIndex:indexInt animated:NO];
}

这可行，但只允许我一次选择一项并检查它。我希望能够一次选择/取消选择多个项目。

Answer 1

它就像一个表格视图。您需要的是选定项目的模型。这需要超过任何给定的轮播视图。所以添加一个property NSMutableSet *selectedItems并用self.selected = [NSMutableSet set];初始化它

当按钮被按下时，您想要将当前索引添加到该集合（该按钮是否切换选择？如果是，那么如果它不存在则您想要添加它，或者如果它存在则移除它）。

NSInteger indexInt = carousel1.currentItemIndex;
NSNumber *index = [NSNumber numberWithInt:indexInt];
if ([self.selected member:index]) {
    [self.selected removeObject:iIndex];
} else {
    [self.selected addObject:index];
}

// now just reload that item, and let the viewForItemAtIndex
// take care of the selection state
[carousel reloadItemAtIndex:indexInt animated:NO];

最后一步是在配置视图时对选择状态做出反应：

- (UIView *)carousel:(iCarousel *)carousel viewForItemAtIndex:(NSUInteger)index reusingView:(UIView *)view {

    if (view == nil) {
        view = [[[NSBundle mainBundle] loadNibNamed:@"ItemView" owner:self options:nil] lastObject];
    }

    // get the checkImg view however you do that already.  if you're confused about this
    // give it a tag when you create it, then find it like this:
    UIImageView *checkImg = (UIImageView *)[view viewWithTag:SOME_TAG];

    NSNumber *indexNum = [NSNumber numberWithInt:index];
    // here's where the view state gets set
    checking.alpha = ([self.selected member:indexNum])? 1.0 : 0.0;

  return view;
}

编辑 - 部分问题似乎是创建然后获取轮播的子视图。 UIView 提供了一个可以提供帮助的标记属性，但发布的代码会出现一些错误。以下是标签的使用方法：

如果您在 IB 中创建图像视图，请使用属性检查器给它一个标签。这里，我给了一个view的tag 32。

现在我上面建议中的 SOME_TAG 应该是 32，所以...

UIImageView *checkImg = (UIImageView *)[view viewWithTag:32];
NSLog(@"%@", checkImg);

// if this doesn't log an image view, then something is wrong.