什么是一些重访时很少不被旋转一个UIView可能的原因是什么?
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11-09-2019 - |
题
我把这个代码到我所有的viewControllers的:
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
if (orientation == UIInterfaceOrientationLandscapeRight) {
CGAffineTransform transform = self.view.transform;
// Use the status bar frame to determine the center point of the window's content area.
//CGRect statusBarFrame = [[UIApplication sharedApplication] statusBarFrame];
//CGRect bounds = CGRectMake(0, 0, statusBarFrame.size.height, statusBarFrame.origin.x);
CGPoint center = CGPointMake(320/2, 480/2);
// Set the center point of the view to the center point of the window's content area.
self.view.center = center;
// Rotate the view 90 degrees around its new center point.
transform = CGAffineTransformRotate(transform, (M_PI / 2.0));
self.view.transform = transform;
}
和我也有:
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationLandscapeRight);
}
我可以看到正确的代码,因为他们应该工作,但过一段时间,有一个难得的机会,主视图控制器不能旋转为横向模式,我把它认为后回是主视图。它发生的几率是非常罕见的,但是这是我唠叨。此外,我可以看到,它更频繁地发生在iPhone上。在模拟器上,我记得它永远不会发生。你知道什么是这种情况的可能原因是什么?谢谢你在前进。
解决方案
我发现我的iphone程序的原因。
其中一个可能的原因是存储器。该方法下面将在系统内存不足可以称为:
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
这是“看不见”的UIView是当调用此方法时卸载。当你即将再次看到这一观点,该设备重载,但也许是因为你设置的参数(旋转等),在一个地方,它不会被当它被重新加载调用。你可以使用:
- (void)viewDidLoad {
UIApplication* application = [UIApplication sharedApplication];
application.statusBarOrientation = UIInterfaceOrientationLandscapeRight;
CGAffineTransform landscapeTransform = CGAffineTransformMakeRotation([MyMath radd:90]);
landscapeTransform = CGAffineTransformTranslate (landscapeTransform, -80, 83);
[self.view setTransform: landscapeTransform];
[super viewDidLoad];
}
有由于我们在实际设备上说实际内存发生在装置中。您可以使用“硬件>模拟内存警告”当您使用模拟器。
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