Fragment FragmentBasic.zip null pointer TextView article
Example have error code:
//developer.android.com/training/basics/fragments/creating.html
Try to change ArticleFragment.java
//developer.android.com/training/basics/fragments/creating.html
Try to change ArticleFragment.java
/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* //www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.fragments;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class ArticleFragment extends Fragment {
final static String ARG_POSITION = "position";
int mCurrentPosition = -1;
TextView articleText;
@Override
// public View onCreateView(LayoutInflater inflater, ViewGroup container,
// Bundle savedInstanceState) {
//
// // If activity recreated (such as from screen rotate), restore
// // the previous article selection set by onSaveInstanceState().
// // This is primarily necessary when in the two-pane layout.
// if (savedInstanceState != null) {
// mCurrentPosition = savedInstanceState.getInt(ARG_POSITION);
// }
//
// // Inflate the layout for this fragment
// return inflater.inflate(R.layout.article_view, container, false);
// }
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// If activity recreated (such as from screen rotate), restore
// the previous article selection set by onSaveInstanceState().
// This is primarily necessary when in the two-pane layout.
if (savedInstanceState != null) {
mCurrentPosition = savedInstanceState.getInt(ARG_POSITION);
}
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.article_view, container, false);
articleText = (TextView) rootView.findViewById(R.id.article);
return rootView;
}
@Override
public void onStart() {
super.onStart();
// During startup, check if there are arguments passed to the fragment.
// onStart is a good place to do this because the layout has already been
// applied to the fragment at this point so we can safely call the method
// below that sets the article text.
Bundle args = getArguments();
if (args != null) {
// Set article based on argument passed in
updateArticleView(args.getInt(ARG_POSITION));
} else if (mCurrentPosition != -1) {
// Set article based on saved instance state defined during onCreateView
updateArticleView(mCurrentPosition);
}
}
public void updateArticleView(int position) {
//TextView article = (TextView) getActivity().findViewById(R.id.article); //Error: article=null.
if (articleText != null)
articleText.setText(Ipsum.Articles[position]);
mCurrentPosition = position;
}
/* ERROR public void updateArticleView(int position) {
TextView article = (TextView) getActivity().findViewById(R.id.article);
article.setText(Ipsum.Articles[position]);
mCurrentPosition = position;
}*/
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// Save the current article selection in case we need to recreate the fragment
outState.putInt(ARG_POSITION, mCurrentPosition);
}
}
396LW NO topic_id
AD
Další témata ....(Topics)
I You use offline work for better building speed of project or for other purpose
https://gradle.org/releases
Offline work:
File - Settings - Gradle
- select Use local gradle distribution
- select path Gradle home:
- check Offline work
https://gradle.org/releases
Offline work:
File - Settings - Gradle
- select Use local gradle distribution
- select path Gradle home:
- check Offline work
main.xml
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
android:orientation="vertical"
android:gravity="top"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<ScrollView
android:id="@+id/scrollView1"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<HorizontalScrollView
android:id="@+id/horizontalScrollView1"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:gravity="top"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<ImageView
android:id="@+id/imageViewObrazekGeometrie"
android:layout_width="360dp"
android:layout_height="777dp"
android:src="@drawable/geometrie_vzorecky" />
</LinearLayout>
</HorizontalScrollView>
</ScrollView>
</LinearLayout>
You have to add constructor!
public static class YourFragment extends Fragment {
//you have to add constructor!!!!!
public YourFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.activity_main, container, false);
return view;
}
}
Calendar dateOfYourBirth = new GregorianCalendar(1998, Calendar.SEPTEMBER, 17); Calendar today = Calendar.getInstance(); Android example.
public class HoriziontalScrollActivity extends Activity {
TextView txtV;
Context cntx;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
txtV = (TextView)findViewById(R.id.idLabel);
cntx = this;
StringBuilder strBuild = new StringBuilder();
// enter your date of birth
Calendar dateOfYourBirth = new GregorianCalendar(1998, Calendar.SEPTEMBER, 17);
Calendar today = Calendar.getInstance();
int yourAge = today.get(Calendar.YEAR) - dateOfYourBirth.get(Calendar.YEAR);
dateOfYourBirth.add(Calendar.YEAR, yourAge);
if (today.before(dateOfYourBirth)) {
yourAge--;
}
strBuild.append("You are " + yourAge + " old!");
txtV.setText(strBuild);
}
}
Definition of ListView in layout main.xml file Android example
Code in Main.java ListView example source code Java Android
<ListView android:id="@+id/idListView"
android:background="#7700CC00"
android:layout_height="wrap_content"
android:layout_width="fill_parent" />
Code in Main.java ListView example source code Java Android
public class Main extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ListView mlistView = (ListView) findViewById(R.id.idListView);
mlistView.setAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1,
new String[] {"Game", "Help", "Home site"}));
mlistView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// When clicked, show a toast with the TextView text Game, Help, Home
Toast.makeText(getApplicationContext(), ((TextView) view).getText(),
Toast.LENGTH_SHORT).show();
}
});
}
}
Editace: 2016-02-21 12:26:17
Počet článků v kategorii: 396
Url:fragment-fragmentbasic-zip-null-pointer-textview-article
