请尝试从这里，我认为它会帮助你。

public class WebViewActivity extends Activity {

private WebView webview;

private static final String TAG = "Main";

private ProgressDialog progressBar;

private TextView header_maintext;

private TextView headeroptiontext;

private RelativeLayout back;

private String url_string="http://www.google.com";

private String header_maintext_string="tittle";

/** Called when the activity is first created. */

@SuppressLint("SetJavaScriptEnabled") @Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

requestWindowFeature(Window.FEATURE_NO_TITLE);

setContentView(R.layout.webview_layout);

url_string = getIntent().getStringExtra("url");

header_maintext_string = getIntent().getStringExtra("header_text");

webview = (WebView)findViewById(R.id.webview01);

header_maintext= (TextView)findViewById(R.id.header_maintext);

header_maintext.setText(header_maintext_string);

headeroptiontext = (TextView)findViewById(R.id.headeroptiontext);

headeroptiontext.setVisibility(View.GONE);

WebSettings settings = webview.getSettings();

settings.setJavaScriptEnabled(true);

webview.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);

webview.getSettings().setLoadWithOverviewMode(true);

webview.getSettings().setUseWideViewPort(true);

back = (RelativeLayout) findViewById(R.id.back_layout);

back.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View arg0)

{

// TODO Auto-generated method stub

if(webview.canGoBack() == true)

{

webview.goBack();

}

else

{

finish();

}

}

});

final AlertDialog alertDialog = new AlertDialog.Builder(this).create();

progressBar = ProgressDialog.show(WebViewActivity.this, "tittle", "Loading...");

webview.setWebViewClient(new WebViewClient() {

public boolean shouldOverrideUrlLoading(WebView view, String url) {

view.loadUrl(url);

return true;

}

public void onPageFinished(WebView view, String url) {

Log.i(TAG, "Finished loading URL: " +url);

if (progressBar.isShowing()) {

progressBar.dismiss();

}

}

public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {

Toast.makeText(WebViewActivity.this, "Oh no! " + description, Toast.LENGTH_SHORT).show();

alertDialog.setTitle("Error");

alertDialog.setMessage(description);

alertDialog.setButton("OK", new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int which) {

return;

}

});

alertDialog.show();

}

});

webview.loadUrl(url_string);

}

@Override

public boolean onKeyDown(int keyCode, KeyEvent event) {

if(event.getAction() == KeyEvent.ACTION_DOWN){

switch(keyCode)

{

case KeyEvent.KEYCODE_BACK:

if(webview.canGoBack() == true){

webview.goBack();

}else{

finish();

}

return true;

}

}

return super.onKeyDown(keyCode, event);

}

}