webView显示progress indicator

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    getWindow().requestFeature(Window.FEATURE_PROGRESS); 
 
    setContentView(R.layout.browser); 
    currentURL = BrowserActivity.this.getIntent().getExtras().getString("currentURL"); 
 
    try { 
        mWebView = (WebView) findViewById(R.id.webview); 
        mWebView.getSettings().setJavaScriptEnabled(true); 
        mWebView.setWebViewClient(new browserActivityClient()); 
        setProgressBarIndeterminateVisibility(true); 
        mWebView.loadUrl(currentURL); 
        setProgressBarIndeterminateVisibility(false); 
    } catch (Exception e) { 
        Log.e(getClass().getSimpleName(), "Browser: " + e.getMessage()); 
        Toast.makeText(this, e.getMessage(), Toast.LENGTH_LONG).show(); 
    }  
}