ios - Swift:向 WKWebView 注入(inject) JS 和 CSS 不起作用

Question

我想尝试将 js 脚本注入(inject) WKWebView，但它不起作用。所以它是一个网页，但是当它加载到 App 上时，我们应该隐藏页眉和页脚。我从配置中获取 CSS URL 并加载它，然后尝试将它与代码中编写的 JS 一起注入(inject)。但是，网络已加载，但预期的事情不起作用。怎么了？

这是代码(我省略了许多与问题无关的代码)

import UIKit
import WebKit

class CustomPageWebViewController: UIViewController, WKNavigationDelegate {

    private var webView: WKWebView = WKWebView()


    override func viewDidLoad() {
        super.viewDidLoad()

        webView.navigationDelegate = self
        view.addSubview(webView)

        // Request web page
        requestWebPage()

    }


    // MARK: - Request Web Page

    func requestWebPage() {
        if let urlString = URL(string: determineURLBasedOnPaymentName()) {
            webView.load(URLRequest(url: urlString))
        }
    }


    //

    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        removeHeaderAndFooter(webView: webView)
    }

    func removeHeaderAndFooter(webView: WKWebView) {
        let cssURLString = ConfigManager.sharedInstance.cssURL
        if cssURLString != "" {
            let cssURL = URL(string: cssURLString)
            if let cssURL = cssURL {
                let sessionConfig = URLSessionConfiguration.default
                let session = URLSession(configuration: sessionConfig, delegate: nil, delegateQueue: nil)
                var request = URLRequest(url: cssURL)
                request.httpMethod = "GET"

                let task = session.dataTask(with: request, completionHandler: { (data: Data!, response: URLResponse!, error: Error!) -> Void in
                    if (error == nil) {
                        let result = String(data: data, encoding: String.Encoding.utf8)!

                        var js = "!function(){var e=document.createElement(\"style\");e.type=\"text/css\",e.innerHTML=window.atob(%@),document.getElementsByTagName(\"head\")[0].appendChild(e);var t=document.createElement(\"style\");t.type=\"text/css\",t.innerHTML=\"#tab-hotel,#tabs-2,.rail-order__flex{display:none;} .search__label--input{height:45px;} #tabs-2{display:block;}\",document.body.appendChild(t)}();"
                        // So after I get the CSS file from the link, I will inject it to the JS file here
                        js = String(format: js, result)

                        // And then inject the whole script to the webview
                        self.webView.evaluateJavaScript(js, completionHandler: { (any, error) in

                        })
                    }
                })
                task.resume()
            }
        }
    }
}

Answer 1

WKWebview 中的 js 消息处理程序执行是使用 WKUserScript 处理的

你可以按照我在链接 WKUserScript not working 中的回答执行 JS

这是我们在WKWebview中执行JS的方式

[objectofWKWebView evaluateJavaScript:yourScript completionHandler:^(id result, NSError *error) {}];

您可以创建 WKWebView 的类别并添加类似的功能

- (NSString *)stringByEvaluatingJavaScriptFromString:(NSString *)script {
__block NSString *resultString = nil;
__block BOOL finished = NO;

[self evaluateJavaScript:script completionHandler:^(id result, NSError *error) {
    if (error == nil) {
        if (result != nil) {
            resultString = [NSString stringWithFormat:@"%@", result];
        }
    } else {
        NSLog(@"evaluateJavaScript error : %@", error.localizedDescription);
    }
    finished = YES;
}];

while (!finished)
{
    [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
}

return resultString;
}