我正在将可变数量的对象（卡片）加载到UIScrollView中。每个卡都是以编程方式从数组中的对象创建的。这个想法是用户可以点击一张卡片，它会翻转，表明它已经完成。当我将对象（卡片）加载到UIScrollView时，只有最后一张卡片会翻转。点击任何其他卡翻转最后一张卡。
我怀疑我需要提供指向我想翻转的对象（卡片）的指针，但我不确定该怎么做。我已经尝试为被点击的按钮分配一个标签但是没有那么远。如何定位UIScrollView中的特定对象以对其执行操作？
这是我到目前为止的代码：
// create a cardScrollView
// if there are not cards for the schedule, display the no cards message.
// if there are cards then create the scroller, add the cards, and then add to screen.
if (cardCount == 0) {
NSLog(@"There are no cards available");
// place a label on screen that tells user there are no cards on the schedule. with animation.
// *** TODO: this will eventually be a better graphical message. ***
UILabel *noScheduleMsg = [[UILabel alloc] initWithFrame:CGRectMake(0, 10, 240, 50)];
noScheduleMsg.backgroundColor = [UIColor clearColor];
[noScheduleMsg setText:@"Opps! It doesn't look like there are picture cards on this schedule!"];
[noScheduleMsg setLineBreakMode:UILineBreakModeCharacterWrap];
noScheduleMsg.numberOfLines = 2;
[noScheduleView addSubview:noScheduleMsg];
// animate the view onto the screen
[UIView animateWithDuration:.3 animations:^{
noScheduleView.alpha = 1.0;
}];
}
else
{
NSLog(@"Display schedule cards");
// check to see if there is a cardview first.
if (!cardView) {
// TODO: check for the last known completed card and show the following card in line.
//create UIView that the scroller will go into.
cardView = [[UIView alloc] initWithFrame:CGRectMake(0, 100, 320, 250)];
//set cardView properties
cardView.backgroundColor = [UIColor clearColor];
//make sure I hide the cardview so that animation to full alpha is completed. Add to main view.
cardView.alpha = 0.0;
[self.view addSubview:cardView];
//create the cardViewScroller. this is where all the cards will be placed.
cardScroller = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 320, 250)];
cardScroller.backgroundColor = [UIColor clearColor];
cardScroller.alwaysBounceVertical = NO;
cardScroller.pagingEnabled = YES;
cardScroller.showsVerticalScrollIndicator = NO;
cardScroller.showsHorizontalScrollIndicator = NO;
cardScroller.scrollEnabled = YES;
int cardscrollWidth = 120;
cardScroller.contentSize = CGSizeMake(cardscrollWidth,80);
//iterate over the scheduleCards array and load each object into a view
NSMutableArray *cards = [[NSMutableArray alloc] initWithArray:[selectedSchedule scheduleCards]];
// this is to create the picture cards. itterate over each object and display in the cardScroller
for (int i = 0; i < cardCount; i++) {
// TODO:
// create the front of the card and put in a UIView object
// create the back of the card and put in a UIView object.
// Add a clear button to each isComplete to each card that is complete. if selected then show the backside of the card.
// Add the flip logic
// tie reset button to clear all isComplete values on the cards.
// pull the right cards from the array at each index
Cards *theCard = [cards objectAtIndex:i];
UIButton *frontBtn = [[UIButton alloc] init];
[frontBtn setFrame:CGRectMake(35, 0, 250, 250)];
frontBtn.backgroundColor = [UIColor clearColor];
[frontBtn setTag:i];
[frontBtn addTarget:self action:@selector(changeTaskStatus:) forControlEvents:UIControlEventTouchUpInside];
//set card border
UIImageView *pcImageViewBg = [[UIImageView alloc] initWithFrame:CGRectMake(35, 0, 250, 250)];
UIImage *bgimg = [UIImage imageNamed:@"bigCardbg@2x"];
[pcImageViewBg setImage:bgimg];
// set card image
UIImageView *pcImageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, 230, 230)];
NSString *ik = [theCard imageKey];
if (ik) {
//get the image key from the store
UIImage *imageToDisplay = [[ScheduleImageStore sharedStore] imageForKey:ik];
// use that image to display in the view
[pcImageView setImage:imageToDisplay];
} else {
//set default image.
[pcImageView setImage:[UIImage imageNamed:@"card"]];
}
// this is the front of the card.
frontCard = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 255, 255)];
// back of the card (done state)
//backCard = [[UIView alloc] initWithFrame:CGRectMake(35, 0, 255, 255)];
//[backCard addSubview:frontBtn];
//backCard.backgroundColor = [UIColor redColor];
// UIview for the flip (container)
CGRect frame;
frame.origin.x = cardScroller.frame.size.width * i - 1;
frame.origin.y = 0;
frame.size = cardScroller.frame.size;
theCardFlipView = [[UIView alloc] initWithFrame:frame];
//theCardFlipView.backgroundColor = [UIColor greenColor];
// add the card views to the interface.
[pcImageViewBg addSubview:pcImageView];
[frontCard addSubview:pcImageViewBg];
[frontCard addSubview:frontBtn];
// this is the container holding the frontcard and backcard
// I need to target the appropriate 'theCardFlipView'
[theCardFlipView addSubview:frontCard];
[cardScroller addSubview:theCardFlipView];
NSLog(@"%i",frontBtn.tag);
}
// set the contentsize of the scroller dynamically. it's based on how many cards there are in the schedule.
cardScroller.contentSize = CGSizeMake(cardScroller.frame.size.width * cardCount, cardScroller.frame.size.height);
//add scroller to card view.
[cardView addSubview:cardScroller];
// animate the cardview into view from transparent to opaque.
[UIView animateWithDuration:.3 animations:^{
cardView.alpha = 1.0;
} completion: ^ (BOOL finished) {
// if I want something to happen after loading the cardView, I could put it here.
}];
}
以下是基于按下按钮的方法：
-(void)changeTaskStatus:(UIButton *)sender {
NSLog(@"button tag: %@",[sender tag]);
if(toggleIsOn){
//NSLog(@"incomplete card");
[UIView transitionWithView:theCardFlipView
duration:0.8
options:UIViewAnimationOptionTransitionFlipFromRight | UIViewAnimationOptionCurveEaseInOut
animations:^{
[[[theCardFlipView subviews] objectAtIndex:0] removeFromSuperview],
[theCardFlipView addSubview:frontCard];
}
completion:^(BOOL finished){
NSLog(@"card complete");
}];
}
else {
//NSLog(@"complete card");
[UIView transitionWithView:theCardFlipView
duration:0.8
options:UIViewAnimationOptionTransitionFlipFromLeft | UIViewAnimationOptionCurveEaseInOut
animations:^{
[[[theCardFlipView subviews] objectAtIndex:0] removeFromSuperview],
[theCardFlipView addSubview:frontCard];
}
completion:^(BOOL finished){
//NSLog(@"front card tag: %i",frontBtn.tag);
NSLog(@"card not complete");
}];
}
toggleIsOn = !toggleIsOn;
}
有什么建议吗？我有一种感觉，这是非常kludgy代码，所以任何建议都会受到欢迎。
答案 0 :(得分：0)
在创建卡片视图的循环中，在底部添加：
theCardFlipView.tag = i + 100; // since you're already using i for those button tags
100是一个任意常数，只要没有其他人使用这些标签就可以了（只要你没有超过99张牌）。
然后，当您按下按钮时，请将其放在最开始处。
thecardFlipView = [cardScrollerView viewWithTag:sender.tag + 100];
您现在拥有的代码会为按钮添加标签，但不会为您想要翻转的实际视图添加标签。你正在使用theCardFlipView而没有将它改为你想要翻转的东西（它只是被分配到循环中的最后一张卡片）。
所有这些说，你甚至可以在没有按钮的情况下实现这一点，你只需要在滚动视图上处理轻击手势并找到哪个卡位于分接点。
修改
看起来你正在使用的切换（toggleIsOn）不是卡片特定的，所以你最终会得到不正确的翻转行为。您应该跟踪哪些卡片被翻转以及哪些卡片没有被翻转，并检查它。如果你的卡是UIView子类的实例，你可以在那里添加一个标志，否则你可能想要维护另一个包含该信息的数组。
答案 1 :(得分：0)
迪马的回答应该可以解决你的问题。
创建一个包含前ui视图和后面uiview的卡片类，并在init语句中设置子视图，加上一个翻转方法可以简单地帮助它。