ios - 在 iPhone X 上横向使用最大屏幕
<p><p>我目前正在设置这样的 WebView 的布局约束:</p>
<pre><code>UIView *theView = self.view;
UILayoutGuide *theGuide = theView.safeAreaLayoutGuide;
inWebView.translatesAutoresizingMaskIntoConstraints = NO;
.active = YES;
.active = YES;
.active = YES;
.active = YES;
</code></pre>
<p>当 View 在 iPhone X 上以横向模式显示时，这会导致左右边距。 WebView 在 View 中水平居中。这在以下草图中显示为 (1)
<a href="/image/xzR52.png" rel="noreferrer noopener nofollow"><img src="/image/xzR52.png" alt="enter image description here"/></a>
WebView 被绘制为绿色区域的位置。 </p>
<p>但我想使用 View 的最大宽度，其中 WebView 延伸到右侧 (2) 或左侧 (3)。这将需要一个动态布局指南来引导和尾随。</p>
<p>我怎样才能做到这一点？</p></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>我通过添加更多约束找到了解决方案:</p>
<pre><code>@property (nonatomic, strong) NSLayoutConstraint *leftFullConstraint;
@property (nonatomic, strong) NSLayoutConstraint *rightFullConstraint;
</code></pre>
<p>并初始化 View 约束:</p>
<pre><code>UIView *theView = self.view;
UILayoutGuide *theGuide = theView.safeAreaLayoutGuide;
NSLayoutConstraint *theConstraint;
inWebView.translatesAutoresizingMaskIntoConstraints = NO;
.active = YES;
theConstraint = ;
theConstraint.priority = UILayoutPriorityDefaultHigh;
theConstraint.active = YES;
theConstraint = ;
theConstraint.priority = UILayoutPriorityDefaultHigh;
theConstraint.active = YES;
.active = YES;
self.leftFullConstraint = ;
self.rightFullConstraint = ;
</code></pre>
<p>注意:新的约束使用左右而不是前后，因为书写方向无关!它们比保存区域布局指南的约束具有更高的优先级。因此，当应用程序激活它时，它们将覆盖对安全区域的约束。</p>
<p>最后，当 trait 集合发生变化时，约束也会更新:</p>
<pre><code>- (void)updateConstraints {
UIDeviceOrientation theOrientation = [ orientation];
switch (theOrientation) {
case UIDeviceOrientationLandscapeLeft:
self.leftFullConstraint.active = NO;
self.rightFullConstraint.active = YES;
break;
case UIDeviceOrientationLandscapeRight:
self.leftFullConstraint.active = YES;
self.rightFullConstraint.active = NO;
break;
default:
self.leftFullConstraint.active = NO;
self.rightFullConstraint.active = NO;
}
}
- (void)traitCollectionDidChange:(UITraitCollection *)inPreviousTraitCollection {
;
;
}
</code></pre>
<p><strong>Swift 4</strong> 也是如此。定义属性:</p>
<pre><code>var leftFullConstraint: NSLayoutConstraint?
var rightFullConstraint: NSLayoutConstraint?
</code></pre>
<p>初始化约束:</p>
<pre><code>if let theView = self.view {
let theGuide = theView.safeAreaLayoutGuide
var theConstraint: NSLayoutConstraint!
inWebView.translatesAutoresizingMaskIntoConstraints = false
theView.topAnchor.constraint(equalTo: inWebView.topAnchor).isActive = true
theConstraint = theGuide.leadingAnchor.constraint(equalTo: inWebView.leadingAnchor)
theConstraint.priority = UILayoutPriorityDefaultHigh
theConstraint.isActive = true
theConstraint = theGuide.trailingAnchor.constraint(equalTo:inWebView.trailingAnchor)
theConstraint.priority = UILayoutPriorityDefaultHigh
theConstraint.isActive = true
theView.bottomAnchor.constraint(equalTo: inWebView.bottomAnchor).isActive = true
self.leftFullConstraint = theView.leftAnchor.constraint(equalTo: inWebView.leftAnchor)
self.rightFullConstraint = theView.rightAnchor.constraint(equalTo: inWebView.rightAnchor)
}
</code></pre>
<p>并更新它们:</p>
<pre><code>func updateConstraints() {
if let leftFullConstraint = self.leftFullConstraint,
let rightFullConstraint = self.rightFullConstraint {
let theOrientation = UIDevice.current.orientation
switch(theOrientation) {
case .landscapeLeft:
leftFullConstraint.isActive = false
rightFullConstraint.isActive = true
break;
case .landscapeRight:
leftFullConstraint.isActive = true
rightFullConstraint.isActive = false
break
default:
leftFullConstraint.isActive = false
rightFullConstraint.isActive = false
}
}
}
override func traitCollectionDidChange(_ inPreviousTraitCollection: UITraitCollection?) {
super.traitCollectionDidChange(inPreviousTraitCollection)
updateConstraints()
}
</code></pre></p>
<p style="font-size: 20px;">关于ios - 在 iPhone X 上横向使用最大屏幕，我们在Stack Overflow上找到一个类似的问题：
<a href="https://stackoverflow.com/questions/48418441/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/48418441/
</a>
</p>
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