Question

当我使用下面提到的代码时，我会在iPhone模拟器上获得所需的淡出淡出屏幕，但是图片似乎是用因子2缩放的：我只得到我初始图片的左上角（=启动）图像），缩放到全屏。在启动画面启动之前，启动图像本身在启动时以正确的大小显示。

在AppDelegate的didFinishLaunchingWithOptions中输入代码。

// 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（iOS 4的iPhone 4S（Retina）），仅在模拟器上：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是什么？提前谢谢！

Answer 1

为imageView设置框架，否则它与图像的尺寸相同
设置正确的contentMode
尝试使用self.window，而不是[navigationController view]

示例：

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];
                    }];    
}

启动画面iOS仅在模拟器上显示且尺寸错误

1 个答案: