iOS動畫效果和實現

  動畫效果提供了狀態或頁面轉換時流暢的用戶體驗，在iOS系統中，我們不須要本身編寫繪製動畫的代碼，Core Animation提供了豐富的api來實現你須要的動畫效果。

    UIKit只用UIView來展現動畫,動畫支持UIView下面的這些屬性改變：

 

• frame  
• bounds  
• center  
• transform  
• alpha 
• backgroundColor 
• contentStretch

 

一、commitAnimations方式使用UIView動畫

- (void)viewDidLoad
{
    [super viewDidLoad];

    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];

    [button setTitle:@"改變" forState:UIControlStateNormal];
    button.frame = CGRectMake(10, 10, 60, 40);
    [button addTarget:self action:@selector(changeUIView) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];

}

- (void)changeUIView{
    [UIView beginAnimations:@"animation" context:nil];
    [UIView setAnimationDuration:1.0f];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.view cache:YES];
    [UIView commitAnimations];
 }

下面是點擊改變後的效果（兩種）：

 

動畫的常量有一下四種

UIViewAnimationTransitionNone,
UIViewAnimationTransitionFlipFromLeft,
UIViewAnimationTransitionFlipFromRight,
UIViewAnimationTransitionCurlUp,
UIViewAnimationTransitionCurlDown,

1.2 交換本視圖控制器中2個view位置

 [self.view exchangeSubviewAtIndex:1 withSubviewAtIndex:0];

先添加兩個view ,一個redview  一個yellowview

 

- (void)viewDidLoad
{
    [super viewDidLoad];
    UIView *redView = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    redView.backgroundColor = [UIColor redColor];
    [self.view addSubview:redView];

    UIView *yellowView = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    yellowView.backgroundColor = [UIColor yellowColor];
    [self.view addSubview:yellowView];

    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [button setTitle:@"改變" forState:UIControlStateNormal];
    button.frame = CGRectMake(10, 10, 300, 40);
    [button addTarget:self action:@selector(changeUIView) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];

    UIButton *button1 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [button1 setTitle:@"改變1" forState:UIControlStateNormal];
    button1.frame = CGRectMake(10, 60, 300, 40);
    [button1 addTarget:self action:@selector(changeUIView1) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button1];

}

- (void)changeUIView1{
    [UIView beginAnimations:@"animation" context:nil];
    [UIView setAnimationDuration:1.0f];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    [UIView setAnimationTransition:UIViewAnimationTransitionCurlDown forView:self.view cache:YES];
    //  交換本視圖控制器中2個view位置
    [self.view exchangeSubviewAtIndex:1 withSubviewAtIndex:0];
    [UIView commitAnimations];
}

 

這樣看起來就像兩頁同樣了。

1.3 、   [UIView setAnimationDidStopSelector:@selector(animationFinish:)];

在commitAnimations消息以前，能夠設置動畫完成後的回調，設置方法是：

    [UIView setAnimationDidStopSelector:@selector(animationFinish:)];

 

二、使用：CATransition

- (void)changeUIView2{
    CATransition *transition = [CATransition animation];
    transition.duration = 2.0f;
      transition.type = kCATransitionPush;
    transition.subtype = kCATransitionFromTop;
    [self.view exchangeSubviewAtIndex:1 withSubviewAtIndex:0];
    [self.view.layer addAnimation:transition forKey:@"animation"];
}

transition.type 的類型能夠有

淡化、推擠、揭開、覆蓋

NSString * const kCATransitionFade;

NSString * const kCATransitionMoveIn;

NSString * const kCATransitionPush;

NSString * const kCATransitionReveal;

這四種，

transition.subtype 

也有四種

NSString * const kCATransitionFromRight;

NSString * const kCATransitionFromLeft;

NSString * const kCATransitionFromTop;

NSString * const kCATransitionFromBottom;

 

2.2 私有的類型的動畫類型：

立方體、吸取、翻轉、波紋、翻頁、反翻頁、鏡頭開、鏡頭關

animation.type = @"cube"
animation.type = @"suckEffect";
animation.type = @"oglFlip";//無論subType is "fromLeft" or "fromRight",official只有一種效果
animation.type = @"rippleEffect";
animation.type = @"pageCurl";
animation.type = @"pageUnCurl"
animation.type = @"cameraIrisHollowOpen ";
animation.type = @"cameraIrisHollowClose ";

下圖是第一個cube立方體的效果：

2.3 CATransition的 startProgress  endProgress屬性

這兩個屬性是float類型的。
能夠控制動畫進行的過程，可讓動畫停留在某個動畫點上，值在0.0到1.0之間。endProgress要大於等於startProgress。

好比上面的立方體轉到，能夠設置endProgress= 0.5，讓動畫停留在轉動通常的位置。

上面這些私有的動畫效果，在實際應用中要謹慎使用。由於在app store審覈時可能會覺得這些動畫效果而拒絕經過。

 

 

三、UIView的 + (void)animateWithDuration

:(NSTimeInterval)duration animations:(void (^)(void))animations completion:(void (^)(BOOL finished))completion

方法。

這個方法是在iOS4.0以後才支持的。

比 1 裏的UIView的方法簡潔方便使用。

DidView裏添加moveView。

moveView = [[UIView alloc] initWithFrame:CGRectMake(10, 180, 200, 40)];
moveView.backgroundColor = [UIColor blackColor];
[self.view addSubview:moveView];

 

- (void)changeUIView3{
    [UIView animateWithDuration:3 animations:^(void){
        moveView.frame = CGRectMake(10, 270, 200, 40);
    }completion:^(BOOL finished){
        UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(20, 20, 40, 40)];
        label.backgroundColor = [UIColor blackColor];
        [self.view addSubview:label];
    }];
}

而後用UIView animateWithDuration動畫移動，移動動畫完畢後添加一個Label。

 

3.二、 animateWithDuration的嵌套使用

- (void)changeUIView3{


    [UIView animateWithDuration:2
                          delay:0
                        options:UIViewAnimationOptionCurveEaseOut animations:^(void){
        moveView.alpha = 0.0;
    }completion:^(BOOL finished){
        [UIView animateWithDuration:1
                              delay:1.0
                            options:UIViewAnimationOptionAutoreverse | UIViewAnimationOptionRepeat
                         animations:^(void){
                             [UIView setAnimationRepeatCount:2.5];
                             moveView.alpha = 1.0;
                         }completion:^(BOOL finished){

                         }];

    }];
}

這個嵌套的效果是先把view變成透明，在從透明變成不透明，重複2.5次透明到不透明的效果。

文中例子的代碼： AnimateDemo