你可以通过webview类中的getProgress方法来跟踪进度状态。

初始化进度状态

private int mProgressStatus = 0;

然后AsyncTask像这样加载:

private class Task_News_ArticleView extends AsyncTask<Void, Void, Void> {
    private final ProgressDialog dialog = new ProgressDialog(
            your_class.this);

    // can use UI thread here
    protected void onPreExecute() {
        this.dialog.setMessage("Loading...");
        this.dialog.setCancelable(false);
        this.dialog.show();
    }

    @Override
    protected Void doInBackground(Void... params) {
        try {
            while (mProgressStatus < 100) {
                mProgressStatus = webview.getProgress();

            }
        } catch (Exception e) {

        }
        return null;

    }

    protected void onPostExecute(Void result) {
        if (this.dialog.isShowing()) {
            this.dialog.dismiss();
        }
    }
}

使用setWebViewClient()并重写onPageFinished()

扩展WebViewClient并调用onPageFinished()如下所示:

mWebView.setWebViewClient(new WebViewClient() {

   public void onPageFinished(WebView view, String url) {
        // do your stuff here
    }
});

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;
    }

}

我发现了一个优雅的解决方案，虽然没有严格测试:

public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);
            if (webView.getProgress() == 100) {
                progressBar.setVisibility(View.GONE);
                webView.setVisibility(View.VISIBLE);
            }
        } 

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。