要在Swift中自动缩放WebView中的网页,我所要做的就是:
var w:UIWebView
w.scalesPageToFit=true
我找不到WKWebView的等效方法,网页在我的应用程序中显得太大。我如何自动缩放WKWebView的内容?
-我正在使用Xcode 7和Swift
我的解决方案是:
extension WKWebView {
private struct key {
static let scale = unsafeBitCast(Selector("scalesPageToFit"), UnsafePointer<Void>.self)
}
private var sourceOfUserScript: String {
return "(function(){n" +
" var head = document.getElementsByTagName('head')[0];n" +
" var nodes = head.getElementsByTagName('meta');n" +
" var i, meta;n" +
" for (i = 0; i < nodes.length; ++i) {n" +
" meta = nodes.item(i);n" +
" if (meta.getAttribute('name') == 'viewport') break;n" +
" }n" +
" if (i == nodes.length) {n" +
" meta = document.createElement('meta');n" +
" meta.setAttribute('name', 'viewport');n" +
" head.appendChild(meta);n" +
" } else {n" +
" meta.setAttribute('backup', meta.getAttribute('content'));n" +
" }n" +
" meta.setAttribute('content', 'width=device-width, user-scalable=no');n" +
"})();n"
}
var scalesPageToFit: Bool {
get {
return objc_getAssociatedObject(self, key.scale) != nil
}
set {
if newValue {
if objc_getAssociatedObject(self, key.scale) != nil {
return
}
let time = WKUserScriptInjectionTime.AtDocumentEnd
let script = WKUserScript(source: sourceOfUserScript, injectionTime: time, forMainFrameOnly: true)
configuration.userContentController.addUserScript(script)
objc_setAssociatedObject(self, key.scale, script, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC)
if URL != nil {
evaluateJavaScript(sourceOfUserScript, completionHandler: nil)
}
} else if let script = objc_getAssociatedObject(self, key.scale) as? WKUserScript {
objc_setAssociatedObject(self, key.scale, nil, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC)
configuration.userContentController.removeUserScript(script)
if URL != nil {
let source = "(function(){n" +
" var head = document.getElementsByTagName('head')[0];n" +
" var nodes = head.getElementsByTagName('meta');n" +
" for (var i = 0; i < nodes.length; ++i) {n" +
" var meta = nodes.item(i);n" +
" if (meta.getAttribute('name') == 'viewport' && meta.hasAttribute('backup')) {n" +
" meta.setAttribute('content', meta.getAttribute('backup'));n" +
" meta.removeAttribute('backup');n" +
" }n" +
" }n" +
"})();"
evaluateJavaScript(source, completionHandler: nil)
}
}
}
}
}
extension WKUserContentController {
public func removeUserScript(script: WKUserScript) {
let scripts = userScripts
removeAllUserScripts()
scripts.forEach {
if $0 != script { self.addUserScript($0) }
}
}
}
这对我来说很有效,如果有更简单或更干净的方法,请告诉我们。在这个例子中,每当设备的屏幕方向改变时,我都会调整WKWebview的大小,将代码放在ViewController中。在我的例子中,我加载的网站已经可以在浏览器中自动调整大小,并且使用这段代码,它也可以在WKWebView中调整大小:
onViewDidLoad{
// other initialization code here...
screenWidth=UIScreen.mainScreen().bounds.width
screenHeight=UIScreen.mainScreen().bounds.height
}
var screenWidth:CGFloat=0
var screenHeight:CGFloat=0
func resizeAccordingToOrientation(){
if UIDevice.currentDevice().orientation.isLandscape.boolValue {
var frame:CGRect = webView!.frame;
frame.size = CGSizeMake(screenHeight, screenWidth-getNavBarHeight())//w,h !!!
frame.origin.x=0
frame.origin.y=getNavBarHeight()
webView!.frame = frame;
//print("Origin x: "+(webView?.frame.origin.x.description)!+" , "+(webView?.frame.origin.y.description)!)
}
else{
var frame:CGRect = webView!.frame;
frame.size = CGSizeMake(screenWidth,screenHeight-getNavBarHeight()-self.navigationController!.navigationBar.frame.origin.y)
frame.origin.x=0
frame.origin.y=getNavBarHeight()+self.navigationController!.navigationBar.frame.origin.y
webView!.frame = frame;
//print("Origin x: "+(webView?.frame.origin.x.description)!+" , "+(webView?.frame.origin.y.description)!)
}
}
func getNavBarHeight() -> CGFloat{
return self.navigationController!.navigationBar.frame.size.height
}