UIWebView 和本地 css 文件
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/2032159/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
UIWebView and local css file
提问by Edward Bender
I want to style a web page meant for the desktop so that it is presentable on a UIWebView on iPhone. I do not have access to the web server from which the pages originate. I would like to do this by changing the hrefattribute of the <link>stylesheet element programmatically.
我想为桌面设计一个网页样式，以便它可以在 iPhone 上的 UIWebView 上呈现。我无权访问页面来源的 Web 服务器。我想通过以编程方式更改样式表元素的href属性来做到这一点<link>。
I do the following with my IBOutlet UIWebView *webView.
我用我的IBOutlet UIWebView *webView.
NSString *cssPath = [[NSBundle mainBundle] pathForResource:@"MyStyleSheet"
ofType:@"css"];
NSString *js = @"document.getElementsByTagName('link').setAttribute('href','";
NSString *js2 = [js stringByAppendingString:cssPath];
NSString *finalJS = [js2 stringByAppendingString:@"');"];
//check element structure
NSString *res = [webView stringByEvaluatingJavaScriptFromString:finalJS];
This does not work. Using the [webView stringByEvaluatingJavaScriptFromString:]message and making a change to the backgroundColorof the body does indeed work - done as an exercise to see if I was using the call correctly.
这不起作用。使用[webView stringByEvaluatingJavaScriptFromString:]消息并对正文进行更改backgroundColor确实有效 - 作为练习来查看我是否正确使用了调用。
Am I barking up the wrong tree?
我是不是叫错了树？
回答by user275790
You can load CSS from local project directory
您可以从本地项目目录加载 CSS
NSString *path = [[NSBundle mainBundle] bundlePath];
NSURL *baseURL = [NSURL fileURLWithPath:path];
[webView loadHTMLString:htmlString baseURL:baseURL];
detail info check this site : http://iphoneincubator.com/blog/windows-views/uiwebview-revisited
详细信息检查这个网站：http: //iphoneincubator.com/blog/windows-views/uiwebview-revisited
回答by Andrew
Unfortunately UIWebViewdoesn't provide an API for intercepting and modifyingthe requests that it makes while loading a resource. This means that any approach you try will be hack-ish to a certain extent.
不幸的是，UIWebView它没有提供用于拦截和修改加载资源时发出的请求的 API 。这意味着您尝试的任何方法在某种程度上都将是hack-ish。
The first approach I would try is:
我会尝试的第一种方法是：
- Provide your own
UIWebViewDelegatedelegate on the view. - Implement
-webView:shouldStartLoadWithRequest:navigationType:and returnNOwhen you spot the CSS requests being made. - Once the view has finished loading the main resource, use
-stringByEvaluatingJavaScriptFromString:to inject JavaScript into the page that dynamically loads/sets the stylesheet that you want to use.
UIWebViewDelegate在视图上提供您自己的委托。- 当您发现正在发出的 CSS 请求时实施
-webView:shouldStartLoadWithRequest:navigationType:并返回NO。 - 视图加载完主要资源后，使用
-stringByEvaluatingJavaScriptFromString:将 JavaScript 注入到动态加载/设置您要使用的样式表的页面中。
In the JavaScript I would create an entirely new <link>element/node on the document instead of trying to modify the existing one.
在 JavaScript 中，我会<link>在文档上创建一个全新的元素/节点，而不是尝试修改现有的元素/节点。
回答by user469350
Your code should work, if you choose index 0 of the found elements:
如果您选择找到的元素的索引 0，您的代码应该可以工作：
NSString *js = @"document.getElementsByTagName('link')[0].setAttribute('href','";
NSString *js2 = [js stringByAppendingString:cssPath];
NSString *finalJS = [js2 stringByAppendingString:@"');"];
[webview stringByEvaluatingJavaScriptFromString:finalJS];
You missed [0]
你错过了 [0]
回答by Jens
SWIFT 3
斯威夫特 3
If you (like me) only use a html snippet (not a complete web page) you need to add your local css file in the header of the html snippet.
如果您（像我一样）只使用 html 片段（不是完整的网页），则需要在 html 片段的标题中添加本地 css 文件。
I therefore define a html header like this:
因此，我定义了一个这样的 html 标题：
let htmlHeader = "<html> \n <head> \n <link href=\"default.css\" rel=\"stylesheet\" type=\"text/css\" /> \n </head> \n <body> \n"
and a footer like this:
和这样的页脚：
let htmlFooter = "</body> \n </html>"
Then find the baseURL for the css like this:
然后像这样找到 css 的 baseURL：
let baseURLForCss = Bundle.main.url(forResource: "default", withExtension: "css")
And load the html snippet with your own css like this:
并使用您自己的 css 加载 html 片段，如下所示：
webView.loadHTMLString(String.init(format: "%@%@&@", htmlHeader, htmlSnippet, htmlFooter), baseURL: baseURLForCss)
