WebViewのページ読み込み中にプログレスを表示するには - 逆引きAndroid入門

サンプルコード

public class MyWebViewActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);

        setContentView(R.layout.main);

        WebView webView = (WebView) findViewById(id.webview);
        
        webView.setWebViewClient(new WebViewClient() {
            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                super.onPageStarted(view, url, favicon);
                setProgressBarIndeterminateVisibility(true);
            }

            @Override
            public void onPageFinished(WebView view, String url) {
                super.onPageFinished(view, url);
                setProgressBarIndeterminateVisibility(false);
            }
        });

        webView.loadUrl(requestToken);
    }
}