参考：http://www.cnblogs.com/hubli/p/4835549.html

APP会跳转网页时候，请参考：http://blog.csdn.net/raphael55/article/details/6975918

效果图：

1.wevbview_progressbar.xml

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <!-- 背景 -->
    <item android:id="@android:id/background">
        <shape>
            <solid android:color="@android:color/transparent" />
        </shape>
    </item>
    <!-- 进度条 -->
    <item android:id="@android:id/progress">
        <clip>
            <shape>
                <solid android:color="@android:color/holo_green_light" />
            </shape>
        </clip>
    </item>
</layer-list>

2.ProgressWebView.java

@SuppressWarnings("deprecation")
public class ProgressWebView extends WebView {
    private final static String TAG = ProgressWebView.class.getSimpleName();

    private ProgressBar progressBar;
    private Context context;

    public ProgressWebView(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.context = context;
        progressBar = new ProgressBar(context, null, android.R.attr.progressBarStyleHorizontal);
        progressBar.setLayoutParams(new AbsoluteLayout.LayoutParams(AbsoluteLayout.LayoutParams.MATCH_PARENT, 3, 0, 0));
        progressBar.setProgressDrawable(getResources().getDrawable(R.drawable.wevbview_progressbar));
        addView(progressBar);
        setWebChromeClient(new WebChromeClient());
    }

    public class WebChromeClient extends android.webkit.WebChromeClient {
        @Override
        public void onProgressChanged(WebView view, int newProgress) {
            Log.d(TAG, "newProgress" + newProgress);
            if (newProgress == 100) {
                progressBar.setVisibility(GONE);
            } else {
                if (progressBar.getVisibility() == GONE)
                    progressBar.setVisibility(VISIBLE);
                progressBar.setProgress(newProgress);
            }
            super.onProgressChanged(view, newProgress);
        }

        // 处理javascript中的console.log
        @Override
        public boolean onConsoleMessage(ConsoleMessage cm){
            android.util.Log.d(TAG, "webview console " + cm.lineNumber() + " of " + cm.sourceId() + " : " + cm.message());
            return true;
        }

        // 处理javascript中的alert()
        @Override
        public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
            result.cancel();
            return true;
        }

    }

    @Override
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
        LayoutParams lp = (LayoutParams) progressBar.getLayoutParams();
        lp.x = l;
        lp.y = t;
        progressBar.setLayoutParams(lp);
        super.onScrollChanged(l, t, oldl, oldt);
    }
}

3.MainActivity.java

ProgressWebView webView = (ProgressWebView)findViewById(R.id.them_webview);

webView.getSettings().setJavaScriptEnabled(true);

webView.setDownloadListener(new DownloadListener() {
    @Override
    public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {
        if (url != null && url.startsWith("http://"))
            startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
    }
});
webView.loadUrl("http://www.cnblogs.com/hubli/p/4835549.html");

4.activity_main.xml

<com.etoury.webviewprogress.ProgressWebView
             android:id="@+id/them_webview"
              android:layout_width="match_parent"
              android:layout_height="match_parent" />