目标C：如何以编程方式在安全区域内创建self.view

Question

我刚刚将我的应用程序从支持iOS 8和更高版本改为支持iOS 9和更高版本。

由于我不使用情节提要板来创建视图，因此我想知道是否有编程方式的 “使用安全区域指南” 选项或类似的选项。

我试图固定我的视图，但它们始终重叠在iPhone X模拟器的顶部和底部。

Answer 1

在Objective-C中尝试此操作，请参见：

UIView * myView = // initialize view using IBOutlet or programtically

myView.backgroundColor = [UIColor redColor];
myView.translatesAutoresizingMaskIntoConstraints = NO;

if (@available(iOS 11, *)) {
    UILayoutGuide * guide = self.view.safeAreaLayoutGuide;
    [myView.leadingAnchor constraintEqualToAnchor:guide.leadingAnchor].active = YES;
    [myView.trailingAnchor constraintEqualToAnchor:guide.trailingAnchor].active = YES;
    [myView.topAnchor constraintEqualToAnchor:guide.topAnchor].active = YES;
    [myView.bottomAnchor constraintEqualToAnchor:guide.bottomAnchor].active = YES;
} else {
    UILayoutGuide *margins = self.view.layoutMarginsGuide;
    [myView.leadingAnchor constraintEqualToAnchor:margins.leadingAnchor].active = YES;
    [myView.trailingAnchor constraintEqualToAnchor:margins.trailingAnchor].active = YES;
    [myView.topAnchor constraintEqualToAnchor:self.topLayoutGuide.bottomAnchor].active = YES;
    [myView.bottomAnchor constraintEqualToAnchor:self.bottomLayoutGuide.topAnchor].active = YES;

}

// Refresh myView and/or main view
[self.view layoutIfNeeded];
//[self.myView layoutIfNeeded];