启动画面 iOS 仅在模拟器上显示且尺寸错误

Question

当我使用下面提到的代码时，我在 iPhone 模拟器上得到了所需的闪屏，但图片似乎放大了 2 倍：我只得到初始图片的左上四分之一（= 启动图像），放大到全屏。在启动画面启动之前，启动图像本身会以正确的大小显示。

代码在 AppDelegate 的 didFinishLaunchingWithOptions 中输入。

// Splash screen
    UIImageView*imageView=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"IMG_1357.png"]];
    [[navigationController view] addSubview:imageView];
    [[navigationController view] bringSubviewToFront:imageView];

    // as usual
    [self.window makeKeyAndVisible];

    //now fade out splash image
    [UIView transitionWithView:self.window duration:4.0f options:UIViewAnimationOptionTransitionNone animations:^(void){imageView.alpha=0.0f;} completion:^(BOOL finished){[imageView removeFromSuperview];}];

此外，启动画面似乎没有出现在设备上（iPhone 4S (Retina) 和 iOS 6.0），只出现在模拟器上：在 iPhone 上运行时，它只显示启动图像。

这两个问题的原因和解决方案可能是什么？ 提前致谢！

Answer 1

1. 为 imageView 设置框架，否则它与图像大小相同
2. 设置正确的 contentMode
3. 尝试使用 self.window，而不是 [navigationController 视图]

例子：

UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"IMG_1357.png"]];
imageView.contentMode = UIViewContentModeScaleAspectFill;
imageView.frame = self.window.bounds;
[self.window addSubview:imageView];
[imageView release];

[self.window makeKeyAndVisible];

//now fade out splash image
[UIView transitionWithView:self.window
                  duration:4.0f
                   options:UIViewAnimationOptionTransitionNone
                animations:^(void) {
                    imageView.alpha = 0.0f;
                }
                completion:^(BOOL finished ){
                    [imageView removeFromSuperview];
                }];

在淡出前添加 1 秒暂停：

int64_t delayInSeconds = 1.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
    [UIView transitionWithView:self.window
                      duration:4.0f
                       options:UIViewAnimationOptionTransitionNone
                    animations:^(void) {
                        imageView.alpha=0.0f;
                    }
                    completion:^(BOOL finished ){
                        [imageView removeFromSuperview];
                    }];
});

或

[self performSelector:@selector(_hideSplash:) withObject:imageView afterDelay:1.0];

- (void) _hideSplash:(UIView *)view
{
    [UIView transitionWithView:self.window
                      duration:4.0f
                       options:UIViewAnimationOptionTransitionNone
                    animations:^(void) {
                        view.alpha=0.0f;
                    }
                    completion:^(BOOL finished ){
                        [view removeFromSuperview];
                    }];    
}