[英]What's the difference between UIWebView and WKWebView when loading local resources
I want to load local resources with webView. 我想用webView加载本地资源。 I built a demo with both UIWebView and WKWebView to do some test with the code below. 我用UIWebView和WKWebView构建了一个演示,用下面的代码做一些测试。
let uiWebView = UIWebView(frame: self.view.bounds)
self.view.addSubview(uiWebView)
let wkWebView = WKWebView(frame:CGRect(x: 0, y: 400, width: 500, height: 500))
self.view.addSubview(wkWebView)
let path = Bundle.main.path(forResource:"1", ofType: "png")
guard let realPath = path else {
return
}
let url = URL(string: realPath)
let fileUrl = URL(fileURLWithPath: realPath)
if let realUrl = url {
uiWebView.loadRequest(URLRequest(url:realUrl))
wkWebView.load(URLRequest(url:realUrl))
}
// uiWebView.loadRequest(URLRequest(url:fileUrl))
// wkWebView.load(URLRequest(url:fileUrl))
The uiWebView can load the resource but wkWebView can not. uiWebView可以加载资源,但wkWebView不能。 But if I use 但是,如果我使用
uiWebView.loadRequest(URLRequest(url:fileUrl))
wkWebView.load(URLRequest(url:fileUrl))
both uiWebView and wkWebView can work well. uiWebView和wkWebView都能很好地工作。 I am confused and can anyone explain that for me: Shouldn't I use URL(string: realPath) for a local resource? 我很困惑,任何人都可以解释一下:我不应该为本地资源使用URL(字符串:realPath)吗? But why UIWebView can use it ? 但是为什么UIWebView可以使用它呢?
A couple points: 几点:
WKWebview
for iOS 8 and later. Apple 建议您在iOS 8及更高版本中使用WKWebview
。 I would avoid writing new code with UIWebView
. 我会避免用UIWebView
编写新代码。 In apps that run in iOS 8 and later, use the
WKWebView
class instead of usingUIWebView
. 在iOS 8及更高版本中运行的应用程序中,使用WKWebView
类而不是使用UIWebView
。 Additionally, consider setting theWKPreferences
propertyjavaScriptEnabled
tofalse
if you render files that are not supposed to run JavaScript. 此外,如果渲染不应运行JavaScript的文件,请考虑将WKPreferences
属性javaScriptEnabled
设置为false
。
/path/to/file.png
and use file:///path/to/file.png
instead. 他们建议您不要使用/path/to/file.png
并使用file:///path/to/file.png
。 As to why one URL works and the other does not, let's make a minimal example: 至于为什么一个URL工作而另一个不工作,让我们做一个最小的例子:
let realPath = "/path/to/file.png"
let url = URL(string: realPath) // /path/to/file.png
let fileUrl = URL(fileURLWithPath: realPath) // file:///path/to/file.png
url
does not provide the scheme (aka protocol). url
不提供方案(aka协议)。 It should only be used in conjunction with another URL to give the absolute address of the resource you are trying to reach. 它应该只与另一个URL一起使用,以提供您尝试访问的资源的绝对地址。 UIWebView
supports it for backwards-compatibility reasons but Apple decided to start clean with WKWebView
. UIWebView
支持它是出于向后兼容的原因,但Apple决定用WKWebView
开始清理。 fileURL
has a scheme ( file://
) that tells the resource is located on the local file system. fileURL
有一个方案( file://
),告诉资源位于本地文件系统上。 Other common schemes are http
, https
, ftp
, etc. It's a complete address to a resource so both views know how to resolve it. 其他常见的方案是http
, https
, ftp
等。它是资源的完整地址,因此两个视图都知道如何解决它。 This might be for security reasons, or just how the WKWebView
API was implemented. 这可能是出于安全原因,或者仅仅是如何实现WKWebView
API。
WKWebView
has a specific instance method for loading local resources called loadFileURL(_:allowingReadAccessTo:)
. WKWebView
有一个特定的实例方法,用于加载名为loadFileURL(_:allowingReadAccessTo:)
WKWebView
loadFileURL(_:allowingReadAccessTo:)
本地资源。 This was introduced in iOS 9. 这是在iOS 9中引入的。
If you are targeting iOS 8.0 or newer, you should be using WKWebView
instead of UIWebView
. 如果您的目标是iOS 8.0或更高版本,则应该使用WKWebView
而不是UIWebView
。 See: https://developer.apple.com/reference/webkit/wkwebview 请参阅: https : //developer.apple.com/reference/webkit/wkwebview
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.