iOS - 逐帧更改图像

Question

我正在尝试逐帧更改 UIImageView 的图像，我有几个应该通过按钮更改的以下图像。这是我的代码:

- (IBAction)next:(id)sender {

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

}

问题是当我点击按钮时，我的代码将图像更改为仅第一帧

Answer 1

因为变量 i 的值始终为 0

尝试以下解决方案:

在.h文件中创建实例变量

int imgCount;

在ViewDidLoad方法中初始化它

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];
}