iPhone:UIImageView淡入淡出-如何？

我有一个

UIImageView

，我想淡入

有没有办法在基础

UIViewController

上启用该功能

我已经为

MonoTouch

用户翻译了最简单的答案，

C#NET

：

public override void ViewDidAppear (bool animated)
{
    base.ViewDidAppear (animated);
    UIView.BeginAnimations ("fade in");
    UIView.SetAnimationDuration (1);
    imageView.Alpha = 1;
    UIView.CommitAnimations ();
}

---

将动画持续时间更改为所需的长度

UIImageView *myImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"myImage.png"]];
myImageView.center = CGPointMake(100, 100);
myImageView.alpha = 0.0;
[self.view addSubview:myImageView];
[UIView animateWithDuration:5.0 animations:^{
     myImageView.alpha = 1.0;
}];

---

最初将imageview的alpha设置为0，即

imageview.alpha=0

- (void)fadeInImage 
{
[UIView beginAnimations:@"fade in" context:nil];
    [UIView setAnimationDuration:1.0];
    imageView.alpha = 1.0;
    [UIView commitAnimations];

}

在
UIViewController中使用以下命令

// add the image view
[self.view addSubview:myImageView];
// set up a transition animation
CATransition *animate = [CATransition animation];
[animate setDuration:self.animationDelay];
[animate setType:kCATransitionPush];
[animate setSubtype:kCATransitionFade];
[animate setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];

[[self layer] addAnimation:animate forKey:@"fade in"];

这个简单的代码：

[UIView animateWithDuration:5.0 animations:^{
        theImage.alpha = 1.0;
    }];

ui图像
位于视图中，并通过
IBOutlet连接
您还可以从实用程序面板设置alpha。
我将使用UIView的+transitionWithView:duration:options:animations:completion:
它是非常有效和强大的

[UIView transitionWithView:imgView duration:1 options:UIViewAnimationOptionTransitionCrossDissolve animations:^{
    imgView.image = [UIImage imageNamed:@"MyImage"];
} completion:nil];

您可以使用以下代码：

淡入动画：

self.yourComponent.alpha = 0.0f;
[UIView beginAnimations:@"fadeIn" context:nil];
[UIView setAnimationDuration:1.0]; // Time in seconds
self.yourComponent.alpha = 1.0f;

self.yourComponent.alpha = 1.0f;
[UIView beginAnimations:@"fadeOut" context:nil];
[UIView setAnimationDuration:1.0]; // Time in seconds
self.yourComponent.alpha = 0.0f;

淡出动画：

self.yourComponent.alpha = 0.0f;
[UIView beginAnimations:@"fadeIn" context:nil];
[UIView setAnimationDuration:1.0]; // Time in seconds
self.yourComponent.alpha = 1.0f;

self.yourComponent.alpha = 1.0f;
[UIView beginAnimations:@"fadeOut" context:nil];
[UIView setAnimationDuration:1.0]; // Time in seconds
self.yourComponent.alpha = 0.0f;

self。您的组件可以是
UIView
、
UIImageView
、
UIButton
或任何其他组件。
Swift版本

func fadeIn(){
    UIView.beginAnimations("fade in", context: nil);
    UIView.setAnimationDuration(1.0);
    imageView.alpha = 1.0;
    UIView.commitAnimations();
}

是否可以只设置UIImageView的动画而不设置UIView的动画？（如果是这样的话，那是怎么回事？）对我来说：我从UI编辑器中添加了一个
UIImageView
，之后（我需要淡出imageview）只添加了示例的最后3行（alpha=0.0），就可以了！