UIViewAnimationOptionTransitionCrossDissolve iOS 5

Question

任何一个可以给我一个例子显示使用UIViewAnimationOptionTransitionCrossDissolve两个图像的crossdissolve效果。

我搜索了很多，但我找不到任何好的例子。

我可以举一些例子吗？

Answer 1

下面的代码是测试，创建两个UIImageView并重叠它们还创建一个图像名称的数组，然后使用下面的动作为下一个（标记= 1）和以前（标记= 0）按钮，将切换图像：

- (void) switchImagesHandler:(int *)sender { 
    UIButton *btn = (UIButton *)sender; 
    switch (btn.tag) { 
    case 0: 
     if (currentImg != 0) { 
      currentImg--; 
      [UIView animateWithDuration:0.3f animations:^{ 
       [firstImage setAlpha:0]; 
      }]; 

      [UIView animateWithDuration:0.3f animations:^{ 
       [firstImage setAlpha:1]; 
       [firstImage setImage:[UIImage imageNamed:[imagesArray objectAtIndex:currentImg]]]; 
      }completion:^(BOOL finished) { 
       [secondImage setImage:[UIImage imageNamed:[imagesArray objectAtIndex:currentImg]]]; 
      }]; 
     } 
     break; 
    case 1: 
     if (currentImg != [imagesArray count]) { 
      currentImg++; 
      [UIView animateWithDuration:0.3f animations:^{ 
       [firstImage setAlpha:0]; 
      }]; 
      [UIView animateWithDuration:0.3f animations:^{ 
       [firstImage setAlpha:1]; 
       [firstImage setImage:[UIImage imageNameds:[imagesArray objectAtIndex:currentImg]]]; 
      } completion:^(BOOL finished) { 
       [secondImage setImage:[UIImage imageNameds:[imagesArray objectAtIndex:currentImg]]]; 
      }]; 
     } 
     break; 
    default: 
     break; 
    } 
}