My WebView does not fill the tabs' screens (but fills the cellphones' screens with no pb)

问题

My app needs to instantiate a WebView that displays the content of a page of a website.

It works perfectly with cellphones (I've tried with various HTC's and with a recent Samsung too) but it doesn't with tablets (Galaxy Tab, or Asus Eee Pad Transformer) : instead of filling the screen the WebView appears very small.

Depending of the tabs, roughly 25% to 50% of the viewport is filled, the rest is blank. It looks a bit as if I was using WRAP_CONTENT instead of FILL_PARENT.

The layout I'm using looks like this:

<?xml version="1.0" encoding="utf-8"?>

<WebView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/webview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
/> 

The onCreate() of the activity that uses this layout looks like this:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.showdoc); // showdoc is the layout above

    // Configuration of the WebView
    final WebView webview = (WebView) findViewById(R.id.webview);
    final WebSettings settings = webview.getSettings();

    settings.setJavaScriptEnabled(true);

    // Callbacks setup 
    final Context ctx = this;

    webview.setWebViewClient(new WebViewClient() {
      public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
        Toast.makeText(ctx, getResources().getString(R.string.error_web) + description, Toast.LENGTH_LONG).show();
      }
    });

    // Display of the page
    webview.loadUrl(getResources().getString(R.string.doc_url) + Locale.getDefault().toString());
}

And the manifest file looks like this:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.example.myapp"
          android:versionCode="1"
          android:versionName="1.0">

    <uses-permission android:name="android.permission.INTERNET" />

    <application android:icon="@drawable/icon" 
                 android:label="@string/app_name" 
                 android:debuggable="true">

    <activity android:name=".MainActivity"
              android:label="@string/app_name"
              android:configChanges="keyboardHidden|orientation">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    </application>

    <uses-sdk android:minSdkVersion="3" />

</manifest> 

When I access to the same URL with the regular browser, the page does properly fill the screen.

The screenshot below were made using a Samsung Galaxy Tab 10 in. emulator, but the result is basically the same on a physical Eee Pad Transformer, the WebView being 50% smaller. On a cellphone, no problem, the WebView takes all the available room.

My app, in landscape mode:

My app, in portrait mode:

Same URL, same hardware, with the default browser, in landscape mode:

Same URL, same hardware, with the default browser, in portrait mode:

So it must be a matter of settings.

WHAT I HAVE UNSUCCESSFULLY TRIED SO FAR:

• Forcing the LayoutParams

I initially thought it was a LayoutParams problem, so I tried adding what follows to my onCreate(), but with no success. It just doesn't change anything:

// Zoom out
final Display display = getWindowManager().getDefaultDisplay(); 

final int width = display.getWidth();
final int height = display.getHeight();

webview.setLayoutParams(new LayoutParams(width, height));

• setScrollBarStyle()

I also looked at this discussion and then tried webview.setScrollBarStyle(WebView.SCROLLBARS_INSIDE_OVERLAY); , but with no success either.

• Using a LinearLayout

I have tried changing the Layout as follows further to your feedback (see below), but it does not change anything:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" 
    android:orientation="vertical">

    <WebView 
        android:id="@+id/webview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
    /> 
</LinearLayout>

Do you have any idea? Thanks in advance!

回答1:

My guess is that it is running in compatibility mode for tablets. Check your manifest file. Could you post a screenshot of what you are seeing?

My suspicion was correct. It is running in compatibility mode.

<supports-screens android:largeScreens="true"
android:normalScreens="true" android:smallScreens="true"
android:anyDensity="true" android:xlargeScreens="false" />

Put this piece of code inside the <manifest> element, just before the <application> tag in your manifest.

回答2:

Try to put your webview in a Linearlayout and make both the height attributes of the Linearlayout and webview has android:layout_height="match_parent"

回答3:

create a new instance of the webView and the KEY is to set the webview to the contentview setContentView(webView); worked for me! hope it helps.

public class DisplayWebPage extends Activity {
WebView webView;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_display_message);

    Intent intent = getIntent(); // Get the message from the intent
    String postString = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

    String url = ("http://api.myDomain.com/sbmRank/app/1/CSS-Slider-Menu.php?action=" + postString);

    webView = new WebView(this);
    setContentView(webView);  //HERE IS THE KEY PART
    WebSettings webSettings = webView.getSettings();
    webSettings.setBuiltInZoomControls(true);

    webView.setWebViewClient(new Callback());
    webView.loadUrl(url);

}

   private class Callback extends WebViewClient{

        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            return (false);
        }

    }

来源：https://stackoverflow.com/questions/6762818/my-webview-does-not-fill-the-tabs-screens-but-fills-the-cellphones-screens-wi