淡出圖像動畫在iphone

Question

可能重複：
iphone fading of images

如何能實現在淡出的動畫的一組圖像（圖像陣列）。圖像將逐一出現。當我使用下面給出的代碼時，它只會顯示一個簡單的幻燈片。

NSArray *imagearray = [NSArray arrayWithObjects: 
          [UIImage imageNamed:@"image1.png"], 
          [UIImage imageNamed:@"imag2.png"],[UIImage imageNamed:@"imag3.png"],[UIImage imageNamed:@"imag4.png"],[UIImage imageNamed:@"imag5.png"],[UIImage imageNamed:@"imag6.png"],[UIImage imageNamed:@"imag7.png"],nil]; 
imageview.animationImages=imagearray; 


imageview.animationDuration = 10.00; 

imageview.animationRepeatCount = 0; 

[imageview startAnimating]; 

我該如何實現衰落效應？

Answer 1

請訪問此堆棧溢出問題的iphone fading of images

- (void)viewDidLoad { 
     imgView.animationImages=[NSArray arrayWithObjects: 
           [UIImage imageNamed:@"lori.png"], 
           [UIImage imageNamed:@"miranda.png"], 
           [UIImage imageNamed:@"taylor.png"], 
           [UIImage imageNamed:@"ingrid.png"], 
           [UIImage imageNamed:@"kasey.png"], 
           [UIImage imageNamed:@"wreckers.png"], nil]; 



     imgView.animationDuration=20.0; 
     imgView.animationRepeatCount=0; 
     [imgView startAnimating]; 
     [self.view addSubview:imgView]; 
     [imgView release]; 
     //The timers time interval is the imageViews animation duration devided by the number of images in the animationImages array. 20/5 = 4 
     NSTimer *timer = [NSTimer timerWithTimeInterval:4.0 
                target:self 
               selector:@selector(onTimer) 
               userInfo:nil 
               repeats:YES]; 

     [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode]; 
     [timer fire]; 

     [super viewDidLoad]; 
    } 

    //It is important that the animation durations within these animation blocks add up to 4 
    //(the time interval of the timer). If you change the time interval then the time intervals 
    //in these blocks must also be changed to refelect the amount of time an image is displayed. 
    //Failing to do this will mean your fading animation will go out of phase with the switching of images. 

    -(void)onTimer{ 
      [UIView animateWithDuration:3.0 animations:^{ 
       imgView.alpha = 0.0; 
      }]; 
      [UIView animateWithDuration:1.0 animations:^{ 
       imgView.alpha = 1.0; 
      }]; 
     } 

Answer 2

動畫視圖的alpha屬性：

[UIView animateWithDuration:5 animations:^{ 
    imageview.alpha = 0; 
}];