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尝试使用选项卡式布局在 SherlockFragment 中制作 WebView，但出现错误。之前有工作代码但尝试更改为 onKeyDown 现在可以工作得到错误。谢谢大家。任何帮助都是极好的。谢谢

代码Java：

 WebView myWebView;

public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    return inflater.inflate(R.layout.fragment_4, container, false);
}

String mURL = "https://www.facebook.com";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Log.v("DetailFragment", "onCreate()");

}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    Log.v("DetailFragment", "onActivityCreated()");
    if (savedInstanceState != null) {
        mURL = savedInstanceState.getString("currentURL", "");
    }

    if (!mURL.trim().equalsIgnoreCase("")) {
        myWebView = (WebView) getView().findViewById(R.id.webView);
        myWebView.loadUrl(mURL.trim());
        myWebView.setWebViewClient(new WebViewClient());
        myWebView.getSettings().setBuiltInZoomControls(true);
        myWebView.getSettings().setSupportZoom(true);
        myWebView.getSettings().setUseWideViewPort(true);
        myWebView.getSettings().setLoadWithOverviewMode(true);
        getView().setOnKeyListener( new OnKeyListener()
        {
            @Override
            public boolean onKey( View v, int keyCode, KeyEvent event )  {
               return  myOnKeyDown(keyCode);
            }
        } );
    }

}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putString("currentURL", mURL);
}

public void setURLContent(String URL) {
    mURL = URL;
}

public void updateURLContent(String URL) {
    mURL = URL;
    myWebView.getSettings().setJavaScriptEnabled(true);
    myWebView.loadUrl(mURL.trim());
    myWebView.setWebViewClient(new WebViewClient());
    myWebView.getSettings().setBuiltInZoomControls(true);
    myWebView.getSettings().setSupportZoom(true);
    myWebView.getSettings().setUseWideViewPort(true);
    myWebView.getSettings().setLoadWithOverviewMode(true);
}

public class WebAppInterface {
    Context mContext;

    /** Instantiate the interface and set the context */
    WebAppInterface(Context fragment_4) {
        mContext = fragment_4;
    }

    /** Show a toast from the web page */
    @JavascriptInterface
    public void showToast(String toast) {
        Toast.makeText(mContext, toast, Toast.LENGTH_SHORT).show();
    }

    private class MyWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            if (Uri.parse(url).getHost().equals("https://www.facebook.com")) {
                // This is my web site, so do not override; let my WebView
                // load the page
                return false;
            }
            return false;
        }
    }

    public boolean myOnKeyDown(int key_code) {
        if ((key_code == KeyEvent.KEYCODE_BACK)
                && myWebView.canGoBack()) {
            myWebView.goBack();
            return true;
        }
        return false;
    }
}


@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.fragment_4, menu);
    return;
}

 }

XML:

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

错误：

  07-27 11:29:57.299: E/AndroidRuntime(6054): FATAL EXCEPTION: main
  07-27 11:29:57.299: E/AndroidRuntime(6054): java.lang.NullPointerException
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at com.bottlecapp.appstest.Fragment_4.onActivityCreated(Fragment_4.java:46)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:1486)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:947)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1460)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:472)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.support.v4.view.ViewPager.populate(ViewPager.java:1068)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.support.v4.view.ViewPager.populate(ViewPager.java:914)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.support.v4.view.ViewPager$3.run(ViewPager.java:244)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.view.Choreographer.doCallbacks(Choreographer.java:562)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.view.Choreographer.doFrame(Choreographer.java:531)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.os.Handler.handleCallback(Handler.java:725)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.os.Handler.dispatchMessage(Handler.java:92)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.os.Looper.loop(Looper.java:137)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at android.app.ActivityThread.main(ActivityThread.java:5041)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at java.lang.reflect.Method.invokeNative(Native Method)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at java.lang.reflect.Method.invoke(Method.java:511)
  07-27 11:29:57.299: E/AndroidRuntime(6054):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
   07-27 11:29:57.299: E/AndroidRuntime(6054):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
   07-27 11:29:57.299: E/AndroidRuntime(6054):  at dalvik.system.NativeStart.main(Native Method)
4

1 回答 1

1

类 memembermyWebView永远不会被初始化。在 onActivityCreated 里面做：

if (!mURL.trim().equalsIgnoreCase("")) {
    myWebView = (WebView) getView().findViewById(R.id.webviewId);
    myWebView.loadUrl(mURL.trim());
    myWebView.setWebViewClient(new WebViewClient());
    myWebView.getSettings().setBuiltInZoomControls(true);
    myWebView.getSettings().setSupportZoom(true);
    myWebView.getSettings().setUseWideViewPort(true);
    myWebView.getSettings().setLoadWithOverviewMode(true);
}

编辑：

改变

  myWebView = (WebView) getView().findViewById(R.id.fragment_4);

和

 myWebView = (WebView) getView().findViewById(R.id.webView);

Edit2：在 onActivityCreated 里面

getView().setOnKeyListener( new OnKeyListener()
{
    @Override
    public boolean onKey( View v, int keyCode, KeyEvent event )  {
       return  myOnKeyDown(keyCode);
    }
} );


 public boolean myOnKeyDown(int key_code) {
        if ((key_code == KeyEvent.KEYCODE_BACK)
                && myWebView.canGoBack()) {
            myWebView.goBack();
            return false;
        }
        return true;
    }
}
于 2013-07-27T10:25:24.573 回答