iOS-逐帧更改图像

Question

I am trying to change an UIImageView's image frame by frame , I have several following image that should be changed by a button . here is my code :

- (IBAction)next:(id)sender {

    for( i = 0; i <= 31; i++ ) {
        NSString* filename = [NSString stringWithFormat:@"pic%d.jpeg",i];
               _image.image = [UIImage imageNamed:filename];
    }

}

the problem is my codes change image to only first frame ,when I tap the button

Answer 1

because of your value of variable i is always 0

Try this for solution:

Create an instance variable in .h file

int imgCount;

initialize it in ViewDidLoad method

imgCount = 0;
NSString* filename = [NSString stringWithFormat:@"pic%d.jpeg",imgCount];  // img0 is displayed
_image.image = [UIImage imageNamed:filename];


- (IBAction)next:(id)sender {
     //first (by default) img0 is display
     imgCount++;

     if (imgCount > 30) {  //suppose total image is 31 means 0 to 30
         imgCount = 0;
     }
     NSString* filename = [NSString stringWithFormat:@"pic%d.jpeg",imgCount];
     _image.image = [UIImage imageNamed:filename];
}

- (IBAction)previous:(id)sender {
     imgCount--;

     if (imgCount < 0) {  //suppose total image is 31 means 0 to 30
         imgCount = 30;
     }
     NSString* filename = [NSString stringWithFormat:@"pic%d.jpeg",imgCount];
     _image.image = [UIImage imageNamed:filename];
}

Answer 2

// create the view that will execute our animation
     UIImageView* campFireView = [[UIImageView alloc] initWithFrame:self.view.frame];

     // load all the frames of our animation
     campFireView.animationImages = [NSArray arrayWithObjects:   
                                 [UIImage imageNamed:@"campFire01.gif"],
                                 [UIImage imageNamed:@"campFire02.gif"],
                                 [UIImage imageNamed:@"campFire03.gif"],
                                 [UIImage imageNamed:@"campFire04.gif"],
                                 [UIImage imageNamed:@"campFire05.gif"],
                                 [UIImage imageNamed:@"campFire06.gif"],
                                 [UIImage imageNamed:@"campFire07.gif"],
                                 [UIImage imageNamed:@"campFire08.gif"],
                                 [UIImage imageNamed:@"campFire09.gif"],
                                 [UIImage imageNamed:@"campFire10.gif"],
                                 [UIImage imageNamed:@"campFire11.gif"],
                                 [UIImage imageNamed:@"campFire12.gif"],
                                 [UIImage imageNamed:@"campFire13.gif"],
                                 [UIImage imageNamed:@"campFire14.gif"],
                                 [UIImage imageNamed:@"campFire15.gif"],
                                 [UIImage imageNamed:@"campFire16.gif"],
                                 [UIImage imageNamed:@"campFire17.gif"], nil];

     // all frames will execute in 1.75 seconds
     campFireView.animationDuration = 1.75;
     // repeat the annimation forever
     campFireView.animationRepeatCount = 0;
     // start animating
     [campFireView startAnimating];
     // add the animation view to the main window
     [self.view addSubview:campFireView];

Also download the source code form here.