Dynamically adding views into a specific fragment layout
36,793
Solved:
public class PageFragment extends Fragment {
private int fragmentNR;
public PageFragment(int nr) {
this.fragmentNR = nr;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = new View(getActivity());
if (fragmentNR == 0)
v = inflater.inflate(R.layout.page1, container, false);
else if (fragmentNR == 1){
v = inflater.inflate(R.layout.page2, container, false);
View tv = v.findViewById(R.id.Ausgabe);
((TextView)tv).setText("TestText");
View pl = v.findViewById(R.id.PageLayout);
TextView Paper = new TextView(pl.getContext());
Paper.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
Paper.setText("Inserted TestText");
((LinearLayout)pl).addView(Paper);
}
else if (fragmentNR == 2)
v = inflater.inflate(R.layout.page3, container, false);
return v;
}
}
Author by
Drilon Berisha
Updated on September 10, 2020Comments
-
Drilon Berisha over 3 years
I am trying to add a TextView dynamically into a layout which is part of a Fragment, but it is not working. As soon as the application starts it shuts down immediately. I think it has to do something with the
TextView Paper = new TextView(this);
part. I dont know how to get the right Context since I'm working with Fragments. Maybe my assumption is wrong but I really dont know where the error might be.public class PageFragment extends Fragment { private int fragmentNR; public PageFragment(int nr) { this.fragmentNR = nr; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View v = new View(getActivity()); if (fragmentNR == 0) v = inflater.inflate(R.layout.page1, container, false); else if (fragmentNR == 1) v = inflater.inflate(R.layout.page2, container, false); else if (fragmentNR == 2) v = inflater.inflate(R.layout.page3, container, false); return v; } }
public class MainActivity extends FragmentActivity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); PageAdapter mPageAdapter = new PageAdapter(getSupportFragmentManager()); ViewPager mViewPager = (ViewPager) findViewById(R.id.viewpager); mViewPager.setAdapter(mPageAdapter); //This is where i try to add my TextView into my Layout LinearLayout PaperLayout = (LinearLayout) findViewById(R.id.PaperLayout);//PaperLayout is a LinearLayout within the Page2-Fragment(R.layout.page2) TextView Paper = new TextView(this); Paper.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); Paper.setText("Paper2"); PaperLayout.addView(Paper); } }
logcat
07-18 16:32:58.330: E/AndroidRuntime(614): FATAL EXCEPTION: main 07-18 16:32:58.330: E/AndroidRuntime(614): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.loni.math_prime/com.loni.math_prime.MainActivity}: java.lang.NullPointerException 07-18 16:32:58.330: E/AndroidRuntime(614): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059) 07-18 16:32:58.330: E/AndroidRuntime(614): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 07-18 16:32:58.330: E/AndroidRuntime(614): at android.app.ActivityThread.access$600(ActivityThread.java:130) 07-18 16:32:58.330: E/AndroidRuntime(614): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 07-18 16:32:58.330: E/AndroidRuntime(614): at android.os.Handler.dispatchMessage(Handler.java:99) 07-18 16:32:58.330: E/AndroidRuntime(614): at android.os.Looper.loop(Looper.java:137) 07-18 16:32:58.330: E/AndroidRuntime(614): at android.app.ActivityThread.main(ActivityThread.java:4745) 07-18 16:32:58.330: E/AndroidRuntime(614): at java.lang.reflect.Method.invokeNative(Native Method) 07-18 16:32:58.330: E/AndroidRuntime(614): at java.lang.reflect.Method.invoke(Method.java:511) 07-18 16:32:58.330: E/AndroidRuntime(614): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 07-18 16:32:58.330: E/AndroidRuntime(614): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 07-18 16:32:58.330: E/AndroidRuntime(614): at dalvik.system.NativeStart.main(Native Method) 07-18 16:32:58.330: E/AndroidRuntime(614): Caused by: java.lang.NullPointerException 07-18 16:32:58.330: E/AndroidRuntime(614): at com.loni.math_prime.MainActivity.onCreate(MainActivity.java:30) 07-18 16:32:58.330: E/AndroidRuntime(614): at android.app.Activity.performCreate(Activity.java:5008) 07-18 16:32:58.330: E/AndroidRuntime(614): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079) 07-18 16:32:58.330: E/AndroidRuntime(614): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023) 07-18 16:32:58.330: E/AndroidRuntime(614): ... 11 more
XML
<?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" > <android.support.v4.view.ViewPager android:id="@+id/viewpager" android:layout_width="fill_parent" android:layout_height="fill_parent" > <android.support.v4.view.PagerTitleStrip android:layout_width="fill_parent" android:layout_height="wrap_content" android:textSize="32dp" android:textStyle="bold" android:textColor="#fff5ee" android:layout_gravity="top" /> </android.support.v4.view.ViewPager> </LinearLayout>