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
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Další témata ....(Topics)
Problem: erroneous entry of id
Solution: @+id/
<RadioButton android:id="idRadio"
android:text="My radio button"/>
Solution: @+id/
<RadioButton android:id="@+id/idRadio"
android:text="My radio button"/>
do while Java example
public class MainClass {
public static void main(String[] arg) {
String[] arrayOfString = { "Hello", "people", "hello", "world!" };
int i = 0;
// first cycle is always executed
do {
System.out.println("Loop: " + i);
System.out.println(arrayOfString[i]);
i++;
}while ( i == -1 );
}
}
/*
Loop: 0
Hello
*/
public class MainClass {
public static void main(String[] arg) {
String[] arrayOfString = { "Hello", "people", "hello", "world!" };
int i = 0;
do {
System.out.println("Loop: " + i);
System.out.println(arrayOfString[i]);
i++;
}while ( i < arrayOfString.length );
}
}
/*
Loop: 0
Hello
Loop: 1
people
Loop: 2
hello
Loop: 3
world!
*/
Sensor, getSystemService(), getSensorList(), getDefaultDisplay(), WindowManager,
Surface.ROTATION_0, onAccuracyChanged() Android sample.
Surface.ROTATION_0, onAccuracyChanged() Android sample.
public class _MotionActivity extends Activity implements SensorEventListener {
private float mSensorX;
private float mSensorY;
private Display mDisplay;
private SensorManager sm;
private PowerManager mPowerManager;
private WindowManager mWindowManager;
TextView textview;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get an instance of the SensorManager
sm = (SensorManager) getSystemService(SENSOR_SERVICE);
if(sm.getSensorList(Sensor.TYPE_ACCELEROMETER).size()!=0){
Sensor s = sm.getSensorList(Sensor.TYPE_ACCELEROMETER).get(0);
sm.registerListener(this,s, SensorManager.SENSOR_DELAY_NORMAL);
}
// Get an instance of the PowerManager
mPowerManager = (PowerManager) getSystemService(POWER_SERVICE);
// Get an instance of the WindowManager
mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
mDisplay = mWindowManager.getDefaultDisplay();
setContentView(R.layout.main);
textview = (TextView)findViewById(R.id.textView1);
}
@Override
public void onSensorChanged(SensorEvent event) {
if (event.sensor.getType() != Sensor.TYPE_ACCELEROMETER)
return;
switch (mDisplay.getRotation()) {
case Surface.ROTATION_0:
mSensorX = event.values[0];
mSensorY = event.values[1];
textview.setText(String.valueOf( mSensorX));
break;
case Surface.ROTATION_90:
mSensorX = -event.values[1];
mSensorY = event.values[0];
textview.setText(String.valueOf( mSensorX));
break;
case Surface.ROTATION_180:
mSensorX = -event.values[0];
mSensorY = -event.values[1];
textview.setText(String.valueOf( mSensorX));
break;
case Surface.ROTATION_270:
mSensorX = event.values[1];
mSensorY = -event.values[0];
textview.setText(String.valueOf( mSensorX));
break;
}
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// TODO Auto-generated method stub
}
@Override
protected void onResume() {
super.onResume();
if(sm.getSensorList(Sensor.TYPE_ACCELEROMETER).size()!=0){
Sensor s = sm.getSensorList(Sensor.TYPE_ACCELEROMETER).get(0);
sm.registerListener(this,s, SensorManager.SENSOR_DELAY_NORMAL);
}
}
@Override
protected void onPause() {
sm.unregisterListener(this);
super.onStop();
}
}
Try reboot device.
Start device with start button on side of phone.
Screen will go to light black color.
Long press Start button for menu:
Power off
Reboot
Airplane mode
Reboot item is in same level like Start button.
Click on the screen - (Hear a click)
Now find OK button , it is under Reboot item on right side of screen.
Press OK (Hear a click)
Wait a moment.
If device to do nothing , try short press Start button (sreen will black)
and again to press Start button. If screen go to light black color,
try again find Reboot item as written above.
Start device with start button on side of phone.
Screen will go to light black color.
Long press Start button for menu:
Power off
Reboot
Airplane mode
Reboot item is in same level like Start button.
Click on the screen - (Hear a click)
Now find OK button , it is under Reboot item on right side of screen.
Press OK (Hear a click)
Wait a moment.
If device to do nothing , try short press Start button (sreen will black)
and again to press Start button. If screen go to light black color,
try again find Reboot item as written above.
ImputStream is = this.getResources().openRawResource(R.drawable.colors);
Bitmap mBitmap2 = BitmapFactory.decodeStream(is);
int w = mBitmap2.getWidth();
int h = mBitmap2.getHeight();
// int x , y have to be smaller as w , h
int _color = mBitmap2.getPixel(x, y);
Editace: 2016-02-21 12:26:17
Počet článků v kategorii: 396
Url:fragment-fragmentbasic-zip-null-pointer-textview-article
