webView.translatesAutoresizingMaskIntoConstraints = false
let height = NSLayoutConstraint(item: webView, attribute: .height, relatedBy: .equal, toItem: view, attribute: .height, multiplier: 1, constant: 0)
let width = NSLayoutConstraint(item: webView, attribute: .width, relatedBy: .equal, toItem: view, attribute: .width, multiplier: 1, constant: 0)
view.addConstraints([height, width])

NSLayoutConstraint *heigth = [NSLayoutConstraint constraintWithItem:_LHMainWebView attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeHeight multiplier:1 constant:0];
NSLayoutConstraint *width = [NSLayoutConstraint constraintWithItem:_LHMainWebView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeWidth multiplier:1 constant:0];
[self.view addConstraints:@[heigth,width]];