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Android

Posted by Neil Quinn
Neil Quinn
768 Points

Fragments help!

I'm not quite sure whats wrong here as my app runs. I get no errors but when I switch from one tab to the one containing "MarketplaceFragment" below, the application quits. This is my logcat error:

03-20 23:24:24.996: E/AndroidRuntime(1977): FATAL EXCEPTION: main

03-20 23:24:24.996: E/AndroidRuntime(1977): java.lang.NullPointerException

03-20 23:24:24.996: E/AndroidRuntime(1977): at com.teamtreehouse.ribbit.MarketplaceFragment.onCreate(MarketplaceFragment.java:20)

here is MarketplaceFragment:

package com.teamtreehouse.ribbit;

import android.os.Bundle; import android.support.v4.app.Fragment; import android.webkit.WebView;

public class MarketplaceFragment extends Fragment {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.fragment_marketplace);

    WebView webView = (WebView) findViewById(R.id.fragment_marketplace_webview);
    webView.loadUrl("http://beta.html5test.com/");
}

private WebView findViewById(int fragmentMarketplaceWebview) {
    return null;
}

private void setContentView(int fragmentMarketplace) {

}

}

2 Answers

Cristian Rivera
Cristian Rivera
2,192 Points

Hola Nell .

Estas creando mal tu "Fragment" , no puedes inicializar un "WebView" o cualquier otra "view" por el método onCreate();

Esta es la manera correcta de crear un "Fragment"

public class MarketplaceFragment extends Fragment {

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

View mView = inflater.inflate(R.layout.fragment_marketplace,container,false);

//Busca  tu WebView en "mView"
WebView webView = (WebView) mView.findViewById(R.id.fragment_marketplace_webview);
webView.loadUrl("http://beta.html5test.com/");
}
Neil Quinn
Neil Quinn
768 Points
Neil Quinn
Neil Quinn
768 Points

Yeah I made the changes, and still the application is quitting. Although I now have more errors in the logcat! I think it has something to do with the use of the fragment and the support library it's using maybe? because I have a lot of erros with "support.v4.app"

03-24 00:05:04.659: E/AndroidRuntime(1370): FATAL EXCEPTION: main

03-24 00:05:04.659: E/AndroidRuntime(1370): java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.

03-24 00:05:04.659: E/AndroidRuntime(1370): at android.view.ViewGroup.addViewInner(ViewGroup.java:3509) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.view.ViewGroup.addView(ViewGroup.java:3380) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.view.ViewGroup.addView(ViewGroup.java:3325) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.view.ViewGroup.addView(ViewGroup.java:3301) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.app.NoSaveStateFrameLayout.wrap(NoSaveStateFrameLayout.java:40) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:931) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1467)

03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:472)

03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.view.ViewPager.populate(ViewPager.java:1068) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:550) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:509) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.support.v4.view.ViewPager.setCurrentItem(ViewPager.java:490) 03-24 00:05:04.659: E/AndroidRuntime(1370): at com.teamtreehouse.ribbit.MainActivity.onTabSelected(MainActivity.java:127) 03-24 00:05:04.659: E/AndroidRuntime(1370): at com.android.internal.app.ActionBarImpl.selectTab(ActionBarImpl.java:572) 03-24 00:05:04.659: E/AndroidRuntime(1370): at com.android.internal.app.ActionBarImpl$TabImpl.select(ActionBarImpl.java:1098)

03-24 00:05:04.659: E/AndroidRuntime(1370): at com.android.internal.widget.ScrollingTabContainerView$TabClickListener.onClick(ScrollingTabContainerView.java:547)

03-24 00:05:04.659: E/AndroidRuntime(1370): at android.view.View.performClick(View.java:4240) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.view.View$PerformClick.run(View.java:17721) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.os.Handler.handleCallback(Handler.java:730) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.os.Handler.dispatchMessage(Handler.java:92) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.os.Looper.loop(Looper.java:137) 03-24 00:05:04.659: E/AndroidRuntime(1370): at android.app.ActivityThread.main(ActivityThread.java:5103) 03-24 00:05:04.659: E/AndroidRuntime(1370): at java.lang.reflect.Method.invokeNative(Native Method) 03-24 00:05:04.659: E/AndroidRuntime(1370): at java.lang.reflect.Method.invoke(Method.java:525) 03-24 00:05:04.659: E/AndroidRuntime(1370): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 03-24 00:05:04.659: E/AndroidRuntime(1370): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 03-24 00:05:04.659: E/AndroidRuntime(1370): at dalvik.system.NativeStart.main(Native Method)