在loadView方法中计算视图大小的最佳实践

Question

在没有XIB文件的情况下，用loadView方法（在UIViewController中）计算视图大小的最佳做法是什么？

这是我的解决方案：

- (void)loadView {
  //Calculate Screensize
  BOOL statusBarHidden = [[UIApplication sharedApplication] isStatusBarHidden ];
  BOOL navigationBarHidden = [self.navigationController isNavigationBarHidden];
  BOOL tabBarHidden = [self.tabBarController.tabBar isHidden];
  CGRect frame = [[UIScreen mainScreen] bounds];
  if (!statusBarHidden) {
    frame.size.height -= [[UIApplication sharedApplication] statusBarFrame].size.height; 
  }
  if (!navigationBarHidden) {
    frame.size.height -= self.navigationController.navigationBar.frame.size.height; 
  }
  if (!tabBarHidden) {
    frame.size.height -= self.tabBarController.tabBar.frame.size.height; 
  }
  UIView *v = [[UIView alloc] initWithFrame: frame];
  [v setBackgroundColor: [UIColor whiteColor] ];
  [v setAutoresizingMask: UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight ];
  [self setView: v ];
  [v release];      
}

这个代码可以吗？还是应该编辑一些内容？

Answer 1

文档建议使用[[UIScreen mainScreen] applicationFrame]在没有状态栏的情况下获得屏幕边界

Answer 2

因此，对于任何想了解最佳实践的人来说，例如：

#pragma mark -
#pragma mark LoadView Methods
- (void)loadView {
  //Calculate Screensize
  BOOL statusBarHidden = [[UIApplication sharedApplication] isStatusBarHidden ];
  BOOL navigationBarHidden = [self.navigationController isNavigationBarHidden];
  BOOL tabBarHidden = [self.tabBarController.tabBar isHidden];
  BOOL toolBarHidden = [self.navigationController isToolbarHidden];
  CGRect frame = [[UIScreen mainScreen] applicationFrame];
  //check if you should rotate the view, e.g. change width and height of the frame
  BOOL rotate = NO;
  if ( UIInterfaceOrientationIsLandscape( [UIApplication sharedApplication].statusBarOrientation ) ) {
    if (frame.size.width < frame.size.height) {
      rotate = YES;
    }
  }
  if ( UIInterfaceOrientationIsPortrait( [UIApplication sharedApplication].statusBarOrientation ) ) {
    if (frame.size.width > frame.size.height) {
      rotate = YES;
    }
  }
  if (rotate) {
    CGFloat tmp = frame.size.height;
    frame.size.height = frame.size.width;
    frame.size.width = tmp;
  }

  if (statusBarHidden) {
    frame.size.height -= [[UIApplication sharedApplication] statusBarFrame].size.height;
  }
  if (!navigationBarHidden) {
    frame.size.height -= self.navigationController.navigationBar.frame.size.height;
  }
  if (!tabBarHidden) {
    frame.size.height -= self.tabBarController.tabBar.frame.size.height;
  }
  if (!toolBarHidden) {
    frame.size.height -= self.navigationController.toolbar.frame.size.height;
  }
  UIView *v = [[UIView alloc] initWithFrame: frame];
  v.backgroundColor = [UIColor whiteColor];
  v.autoresizingMask  = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
  self.view = v;
  [v release]; //depends on your ARC configuration
}

Answer 3

您正在根据状态栏和导航栏调整高度。。但是你没有对这个观点的起源做任何事情。