Fragment FragmentBasic.zip null pointer TextView article
AD MOB
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);
}
}
397LW NO topic_id
AD
Další témata ....(Topics)
Java double is 64 bit double precision type used when fractional
precision calculation is required.
Java double je datový typ (reálné číslo) o velikosti 64 bitů. Používá se například pro přesný výsledek po dělení za desetinnou tečkou. Pokud nepotřebuje tak veliké číslo použijte raději typ float, šetříte tím paměť mobilního telefonu.
precision calculation is required.
Java double je datový typ (reálné číslo) o velikosti 64 bitů. Používá se například pro přesný výsledek po dělení za desetinnou tečkou. Pokud nepotřebuje tak veliké číslo použijte raději typ float, šetříte tím paměť mobilního telefonu.
// declaration and assignment of value type double
double x = 18.41785;
//print formated value
System.out.printf("The value of x is %.3f%n", x); // 18.418
// declaring more variables in single statement
double d1 = 12.4, d2 = 564.5, d3 = 14.589;
// double range of value
System.out.println(Double.MIN_VALUE); // 4.9E-324
System.out.println(Double.MAX_VALUE); // 1.7976931348623157E308
// is NaN Not-a-Number
double f = (double) Math.sqrt(-15);
boolean bNaN = Double.isNaN(f);
System.out.print(bNaN); // true
// check if a string is a valid number in Java example
// convert string to double Java example
String sD = "12.8";
double dParse = Double.parseDouble(sD);
// convert strings to numbers
String sDl = "15.48";
double dFromString = (Double.valueOf(sDl)).doubleValue();
// format double, float or long value to string
DecimalFormat formatter = new DecimalFormat(".##");
String s = formatter.format(-.5678); // -0.57
// .### -0.568
// .#### -0.5678
// .000000 -.567800
// -123.456
// .## -123.46
// #.## -123.46
// #E0 -.1E3
// ##E0 -1.2E2
//###E0 -123E0
// double to string in Java example code
Double dObj = new Double(68.5);
String str = dObj.toString();
// else
Double dS = 11.6;
String sdouble = dS.toString();
// compare two double variables
Double dComp1 = 4.3;
if(dComp1.equals(4.3))
System.out.print("true");
// compares the two specified double values in Java example
// int i = compare(double d1, double d2);
int i = Double.compare(11.5, 11.7); // -1 first < second
// 0 first == second
// 1 first > second
System.out.print(i);
Drawable dr = getResources().getDrawable(R.drawable.algebra);
int h = dr.getIntrinsicHeight();
int w = dr.getIntrinsicWidth();
Bitmap ball = BitmapFactory.decodeResource(getResources(), R.drawable.algebra);
int _nWidth = ball.getWidth();
int _nHeight = ball.getHeight();
(Our software)
| 1 | Samsung Galaxy S2 | 13.8% (1,232) |
| 2 | Samsung Galaxy S | 8.5% (762) |
| 3 | Samsung Galaxy Tab | 7.4% (659) |
| 4 | Samsung Galaxy Mini | 5.4% (483) |
| 5 | Samsung Galaxy S | 4.0% (356) |
| 6 | HTC Desire HD | 3.8% (341) |
| 7 | Samsung Galaxy Ace | 3.8% (339) |
| 8 | HTC Wildfire | 3.2% (286) |
| 9 | Samsung Galaxy Fit | 3.1% (274) |
| 10 | SEMC Xperia X10 | 2.1% (190) |
StringBuilder, res/raw folder, try catch finaly throws, BufferedReader, InputStream, openRawResource, getResources Android example
MainActivity.java
MainActivity.java
public class MainActivity 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;
try {
StringBuilder strBuilder = myFunction(cntx);
txtV.setText(strBuilder);
} catch (IOException e) {
e.printStackTrace();
}
}
private StringBuilder myFunction(Context context) throws IOException {
final Resources resources = context.getResources();
InputStream inputStream = resources.openRawResource(R.raw.my_file);
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder strBuild = new StringBuilder();
try {
String line;
while ((line = reader.readLine()) != null) {
strBuild.append(line);
}
} finally {
reader.close();
}
return strBuild;
}
}
Call requires permission which may be rejected by user: code should explicitly check to see if permission is available (with `checkPermission`) or explicitly handle a potential `SecurityException`
try {
// your code for example:
// LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
// Criteria criteria = new Criteria();
// provider = locationManager.getBestProvider(criteria, false);
// locationManager.requestLocationUpdates(provider, 400, 1, this);
} catch (SecurityException e) {
e.printStackTrace();
}
Editace: 2016-02-21 12:26:17
Počet článků v kategorii: 397
Url:fragment-fragmentbasic-zip-null-pointer-textview-article
AD
