中心视图不起作用

Posted 2023-02-26

【中文标题】中心视图不起作用

【英文标题】：center view doesn't work

【发布时间】：2011-12-21 15:35:18

【问题描述】：

我尝试根据界面方向将显示在我的 iPad 应用程序中的视图居中。 这不起作用，视图总是会根据应用启动的方向发生变化。

我已经通过 *** 搜索了 2 个小时，尝试了不同的方法，但无法成功。

这就是我从根视图显示视图的方式：

publicationDownload = [[PublicationDownloadController alloc] init];
// Setting up propertys to load Publication-related information
[publicationDownload setDelegate:self];
[publicationDownload setThePubID:[NSNumber numberWithInt:[sender tag]]];

publicationDownload.view.opaque = NO;
publicationDownload.view.backgroundColor = [UIColor clearColor];
[publicationDownload.theUIView.layer setCornerRadius:5];
[publicationDownload.theUIView.layer setShadowColor:[UIColor blackColor].CGColor];
[publicationDownload.theUIView.layer setShadowOpacity:0.5];
[publicationDownload.theUIView.layer setShadowRadius:5];
[publicationDownload.theUIView.layer setShadowOffset:CGSizeMake(3.0f, 3.0f)];
publicationDownload.theUIView.clipsToBounds = NO;
publicationDownload.theUIView.backgroundColor = [UIColor clearColor];
[publicationDownload.theInnerUIView.layer setCornerRadius:5];
[publicationDownload.theInnerUIView.layer setShadowColor:[UIColor blackColor].CGColor];
[publicationDownload.theInnerUIView.layer setShadowOpacity:0.5];
[publicationDownload.theInnerUIView.layer setShadowRadius:5];
[publicationDownload.theInnerUIView.layer setShadowOffset:CGSizeMake(3.0f, 3.0f)];
[publicationDownload.theInnerUIView.layer setMasksToBounds:YES];
publicationDownload.theUIView.layer.masksToBounds = NO;
publicationDownload.view.clipsToBounds = YES;
publicationDownload.view.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:.5];

[self.view addSubview:publicationDownload.view];

在我实现的publicationDownloadViewController 中：

在viewDidLoad: // 在从 nib 加载视图后做任何额外的设置。

//self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight; 
//self.view.contentMode = UIViewContentModeRedraw;
self.view.autoresizesSubviews = YES;
//self.view.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
self.view.frame = self.view.bounds;
//theUIView.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleTopMargin;

NSLog(@"PublicationDownloadController: viewDidLoad:");
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didRotate:) name:UIDeviceOrientationDidChangeNotification object:nil];    
UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];

if (orientation == UIInterfaceOrientationPortrait || orientation == UIInterfaceOrientationPortraitUpsideDown) 
    theUIView.frame = CGRectMake(212, 229, 600, 240);
    self.view.frame = CGRectMake(0, 0, 1024, 768);
 else if (orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight) 
    theUIView.frame = CGRectMake(140, 380, 600, 240);
    self.view.frame = CGRectMake(0, 0, 768, 1024);

以及其他：

-(void)didRotate:(NSNotification*)notification

    NSLog(@"PublicationDownloadController: didRotate");
UIDeviceOrientation oreo = [[UIDevice currentDevice] orientation];
// oreo is our new orientation!
if (oreo == UIInterfaceOrientationPortrait || oreo == UIInterfaceOrientationPortraitUpsideDown) 
    //theUIView.frame = CGRectMake(212, 229, 600, 240);
    self.view.frame = self.view.bounds;
 else if (oreo == UIInterfaceOrientationLandscapeLeft || oreo == UIInterfaceOrientationLandscapeRight) 
    //theUIView.frame = CGRectMake(140, 380, 600, 240);
    self.view.frame = self.view.bounds;

视图本身包含一个横向视图，其背景设置为黑色和 alpha 0.5（在 IB 中）- 另外还有另一个视图 (theUIView) 包含一些 UIControls。这个theUIView 需要居中。如果 ste 应用程序在横向视图中启动，它可以工作，但如果方向更改为纵向则不能。此外，如果应用以纵向启动，则视图不会居中显示。

非常感谢任何帮助！

【问题讨论】：

为什么不重写 UIViewController 类的- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation 方法？

我这样做了，但是这两种方法都没有被调用。

【参考方案1】：

这比预期的要容易。在 Interface Builder 中处理 autoresizemask 并清理一些杂乱的代码就可以了。