objective-c卡翻轉設置圖像爲這兩個網站

Question

我試圖創建一個flashcard應用程序，我試過這個代碼，但它只顯示第一個圖像。

任何人都可以幫助我嗎？

@implementation CardsViewController 
- (IBAction)Flip:(UIButton*)sender 
{ 
    if ([sender.currentImage isEqual:[UIImage imageNamed:@"a"]]) 
    { 
     [sender setBackgroundImage:[UIImage imageNamed:@"b"] 
            forState:UIControlStateNormal]; 
    } 
    else 
    { 
     [sender setBackgroundImage: 
       [UIImage imageNamed:@"a"] forState:UIControlStateNormal]; 

    } 

} 

Answer 1

聽到的是簡單的方式

希望這可以幫助你..

@interface ViewController() 
{ 
    BOOL ButtonClicked;//to trake change images .. 
} 

@end 

@implementation ViewController 

- (void)viewDidLoad 
    { 

    [super viewDidLoad]; 
    ButtonClicked = NO; 
// Do any additional setup after loading the view, typically from a nib. 

    [self.button setImage:[UIImage imageNamed:@"a.png"] forState:UIControlStateNormal];   //change the type of button to custom in the xib 
} 

- (IBAction)whenClicked:(id)sender 
{ 
    if(ButtonClicked) 
    { 
     ButtonClicked = NO; 
     [UIView animateWithDuration:0.8 animations:^{ 
     [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:self.button cache:YES]; 
     [self.button setImage:[UIImage imageNamed:@"a.png"] forState:UIControlStateNormal]; 
     }]; 



    } 
    else 
    { 
     ButtonClicked = YES; 

     [UIView animateWithDuration:0.8 animations:^{ 
     [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:self.button cache:YES]; 
     [self.button setImage:[UIImage imageNamed:@"b.png"] forState:UIControlStateNormal]; 
     }]; 
    } 

} 

Answer 2

您正在設置背景圖像，但使用「currentImage」，即前景圖像作爲比較。

嘗試更換：

if ([sender.currentImage isEqual:[UIImage imageNamed:@"a"]]) 

與

if ([sender.currentBackgroundImage isEqual:[UIImage imageNamed:@"a"]]) 

Answer 3

我想你應該創建一個視圖包含兩個子視圖，然後就進行轉換，[UIView的transitionFromView：toView：持續時間：選擇：完成：]

代碼片段：

UIButton *containerView = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
containerView.frame = CGRectMake(100.0, 100.0, 120.0, 120.0); 
[containerView addTarget:self action:@selector(transition:) forControlEvents:UIControlEventTouchUpInside]; 

UIImageView *imageView1 = [[UIImageView alloc] initWithFrame:containerView.bounds]; 
UIImageView *imageView2 = [[UIImageView alloc] initWithFrame:containerView.bounds]; 
imageView1.image = [UIImage imageNamed:@"Sample1"]; 
imageView2.image = [UIImage imageNamed:@"Sample2"]; 
imageView1.tag = 1; 
imageView2.tag = 2; 

[containerView addSubview:imageView1]; 
[containerView addSubview:imageView2]; 

[self.view addSubview:containerView]; 

- (void)transition:(UIButton *)sender { 
    UIImageView *imageView1 = (UIImageView *)[sender viewWithTag:1]; 
    UIImageView *imageView2 = (UIImageView *)[sender viewWithTag:2]; 

    static NSInteger index = 0; 
    index++; 
    if (index % 2 == 0) { 
     [UIView transitionFromView:imageView1 toView:imageView2 duration:1.0 options:UIViewAnimationOptionTransitionFlipFromRight | UIViewAnimationOptionShowHideTransitionViews completion:NULL]; 
    } else { 
     [UIView transitionFromView:imageView2 toView:imageView1 duration:1.0 options:UIViewAnimationOptionTransitionFlipFromRight | UIViewAnimationOptionShowHideTransitionViews completion:NULL]; 
    } 
} 

Answer 4

而不是使用的背景圖片;一種方式就可以實現翻頁效果是通過使用UIButton的狀態和設置您的圖像作爲默認圖像之一的「正常」狀態，另一個圖像作爲「選定」狀態的默認圖像;您甚至可以在設計時設置這些圖像，然後只通過方法Flip更改按鈕的狀態，這會自動將顯示的圖像更改爲用戶。

請注意，對於每個按鈕狀態，您可以設置兩個圖像，一個默認圖像和一個背景圖像。您甚至不需要/必須設置背景圖像，或者每次選擇按鈕時都不斷更改背景圖像。

@implementation CardsViewController 
- (IBAction)Flip:(UIButton*)sender 
{ 
    if ([sender isSelected]) 
    { 
     [sender setSelected:NO]; 
    } 
    else 
    { 
     [sender setSelected:YES]; 
    } 

} 

如果你想要或需要通過代碼來設置你的圖像，添加這些行中，只有觸發一次，通常的viewDidLoad方法：

[yourButtonInstance setImage:[UIImage imageNamed:@"a"] forState:UIControlStateNormal]; 
[yourButtonInstance setImage:[UIImage imageNamed:@"b"] forState:UIControlStateSelected];