这里有一个方法，它允许你注册一个Runnable，一旦一个特定的网页地址完成加载就会被执行。我们将每个可运行对象与Map中对应的URL字符串相关联，并使用WebView的getOriginalUrl()方法来选择适当的回调。

package io.github.cawfree.webviewcallback;

/**
 *  Created by Alex Thomas (@Cawfree), 30/03/2017.
 **/

import android.net.http.SslError;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.webkit.SslErrorHandler;
import android.webkit.WebView;
import android.webkit.WebViewClient;

import java.util.HashMap;
import java.util.Map;

/** An Activity demonstrating how to introduce a callback mechanism into Android's WebView. */
public class MainActivity extends AppCompatActivity {

    /* Member Variables. */
    private WebView               mWebView;
    private Map<String, Runnable> mCallbackMap;

    /** Create the Activity. */
    @Override protected final void onCreate(final Bundle pSavedInstanceState) {
        // Initialize the parent definition.
        super.onCreate(pSavedInstanceState);
        // Set the Content View.
        this.setContentView(R.layout.activity_main);
        // Fetch the WebView.
        this.mWebView     = (WebView)this.findViewById(R.id.webView);
        this.mCallbackMap = new HashMap<>();
        // Define the custom WebClient. (Here I'm just suppressing security errors, since older Android devices struggle with TLS.)
        this.getWebView().setWebViewClient(new WebViewClient() {
            /** Handle when a request has been launched. */
            @Override public final void onPageFinished(final WebView pWebView, final String pUrl) {
                // Determine whether we're allowed to process the Runnable; if the page hadn't been redirected, or if we've finished redirection.
                if(pUrl.equals(pWebView.getOriginalUrl())) {
                    // Fetch the Runnable for the OriginalUrl.
                    final Runnable lRunnable = getCallbackMap().get(pWebView.getOriginalUrl());
                    // Is it valid?
                    if(lRunnable != null) { lRunnable.run(); }
                }
                // Handle as usual.
                super.onPageFinished(pWebView, pUrl);
            }
            /** Ensure we handle SSL state properly. */
            @Override public final void onReceivedSslError(final WebView pWebView, final SslErrorHandler pSslErrorHandler, final SslError pSslError) { pSslErrorHandler.proceed(); }
        });
        // Assert that we wish to visit Zonal's website.
        this.getWebView().loadUrl("http://www.zonal.co.uk/");
        // Align a Callback for Zonal; this will be serviced once the page has loaded.
        this.getCallbackMap().put("http://www.zonal.co.uk/", new Runnable() {     @Override public void run() { /* Do something. */ } });
    }

    /* Getters. */
    public final WebView getWebView() {
        return this.mWebView;
    }

    private final Map<String, Runnable> getCallbackMap() {
        return this.mCallbackMap;
    }

}

对于Kotlin用户:

webView.webViewClient = object : WebViewClient() {
            override fun onPageFinished(view: WebView?, url: String?) {
                // do your logic
            }
        }

有很多方法你可以重写

我把NeTeInStEiN的代码简化成这样:

mWebView.setWebViewClient(new WebViewClient() {
        private int       webViewPreviousState;
        private final int PAGE_STARTED    = 0x1;
        private final int PAGE_REDIRECTED = 0x2;

        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String urlNewString) {
            webViewPreviousState = PAGE_REDIRECTED;
            mWebView.loadUrl(urlNewString);
            return true;
        }

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            super.onPageStarted(view, url, favicon);
            webViewPreviousState = PAGE_STARTED;
            if (dialog == null || !dialog.isShowing())
                dialog = ProgressDialog.show(WebViewActivity.this, "", getString(R.string.loadingMessege), true, true,
                        new OnCancelListener() {

                            @Override
                            public void onCancel(DialogInterface dialog) {
                                // do something
                            }
                        });
        }

        @Override
        public void onPageFinished(WebView view, String url) {

            if (webViewPreviousState == PAGE_STARTED) {
                dialog.dismiss();
                dialog = null;
            }

        }
 });

这很容易理解，OnPageFinished如果之前的回调是onpagstarted，所以页面是完全加载的。

只是为了显示进度条，“onpagstarted”和“onPageFinished”方法就足够了;但如果你想有一个“is_loading”标志(以及页面重定向，…)，这个方法可以执行非排序，如“onpagstarted > onpagstarted > onPageFinished > onPageFinished”队列。

但与我的短测试(自己测试)，“onProgressChanged”方法值队列是“0-100 > 0-100 > 0-100 >…”

private boolean is_loading = false;

webView.setWebChromeClient(new MyWebChromeClient(context));

private final class MyWebChromeClient extends WebChromeClient{
    @Override
    public void onProgressChanged(WebView view, int newProgress) {
        if (newProgress == 0){
            is_loading = true;
        } else if (newProgress == 100){
            is_loading = false;
        }
        super.onProgressChanged(view, newProgress);
    }
}

如果活动关闭是一个静态变量，也要在活动关闭时设置“is_loading = false”，因为活动可以在页面结束之前完成。

用这个应该会有帮助。' var currentUrl = "google.com" var partOfUrl = currentUrl。currentUrl.length-2 substring (0)

webView.setWebViewClient（object： WebViewClient（） {

override fun onLoadResource(WebView view, String url) {
     //call loadUrl() method  here 
     // also check if url contains partOfUrl, if not load it differently.
     if(url.contains(partOfUrl, true)) {
         //it should work if you reach inside this if scope.
     } else if(!(currentUrl.startWith("w", true))) {
         webView.loadurl("www.$currentUrl")

     } else if(!(currentUrl.startWith("h", true))) {
         webView.loadurl("https://$currentUrl")

     } else { ...}


 }

override fun onReceivedSslError(view: WebView?, handler: SslErrorHandler?, error: SslError?) {
   // you can call again loadUrl from here too if there is any error.
}

//你也应该覆盖其他覆盖错误的方法，如onReceiveError，以查看所有这些方法是如何一个接一个地被调用的，以及它们在调试断点时的行为。 ｝ ｀

我非常倾向于@NeTeInStEiN(和@polen)解决方案，但会用一个计数器来实现它，而不是多个布尔值或状态监视器(只是另一种风格，但我认为可能会共享)。它确实有一个JS的细微差别，但我觉得逻辑是更容易理解一点。

private void setupWebViewClient() {
    webView.setWebViewClient(new WebViewClient() {
        private int running = 0; // Could be public if you want a timer to check.

        @Override
        public boolean shouldOverrideUrlLoading(WebView webView, String urlNewString) {
            running++;
            webView.loadUrl(urlNewString);
            return true;
        }

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            running = Math.max(running, 1); // First request move it to 1.
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            if(--running == 0) { // just "running--;" if you add a timer.
                // TODO: finished... if you want to fire a method.
            }
        }
    });
}