Develop Reference

Android Widget freezes after some time

I have made a counter widget. There are two buttons, one to increase and one to decrease the number. The number is displayed on a TextView. At first everything works just fine, but after some time (usually around an hour) the Textview freezes i.e. I click the buttons but the number doesen't change.
When I click the buttons, the "clicking animation" is still played, so the buttons might still work.
When I remove the widget and replace it again, the widget starts to work again but the same problem occurs after around the same time.
The code is here:
WidgetProvider
package com.example.myapplication;
import android.app.PendingIntent;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.widget.RemoteViews;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
public class WidgetProvider1 extends AppWidgetProvider {
String widgettextviewtext;
final String INCREASE= "sdfjkldjldkf";
final String DECREASE = "skdhbcvouweoaior";
#Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget_layout);
MainActivity.zahl = 15;
remoteViews.setTextViewText(R.id.textView, ""+MainActivity.zahl);
remoteViews.setOnClickPendingIntent(R.id.button3,onClickPendingIntent(context,ZAHLGROESSER) );
remoteViews.setOnClickPendingIntent(R.id.button2,onClickPendingIntent(context,ZAHLKLEINER) );
appWidgetManager.updateAppWidget(appWidgetIds, remoteViews);
updateWidgetNow(context,remoteViews);
super.onUpdate(context, appWidgetManager, appWidgetIds);
}
#Override
public void onReceive(Context context, Intent intent) {
RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget_layout);
//if increase button is clicked
if(intent.getAction().equals(INCREASE)){
if(MainActivity.zahl == 15) {
Toast.makeText(context, "STOOOP!!!", Toast.LENGTH_SHORT).show();
}else{
MainActivity.number = MainActivity.number+1;
String text=""+ MainActivity.number;
remoteViews.setTextViewText(R.id.textView, text);
updateWidgetNow(context, remoteViews);
}
}
//if decrease button is clicked
if(intent.getAction().equals(DECREASE)) {
if (MainActivity.number == 0) {
Toast.makeText(context, "Hurray!", Toast.LENGTH_SHORT).show();
}else{
MainActivity.number = MainActivity.number - 1;
String text = "" + MainActivity.number;
remoteViews.setTextViewText(R.id.textView, text);
updateWidgetNow(context, remoteViews);
}
}
super.onReceive(context, intent);
}
public void updateWidgetNow (Context context, RemoteViews remoteViews){
ComponentName widgetComponent = new ComponentName(context, WidgetProvider1.class);
AppWidgetManager.getInstance(context).updateAppWidget(widgetComponent, remoteViews);
}
public PendingIntent onClickPendingIntent (Context context, String stringAction){
Intent onClickIntent = new Intent(context, WidgetProvider1.class);
onClickIntent.setAction(stringAction);
return PendingIntent.getBroadcast(context,0,onClickIntent,PendingIntent.FLAG_UPDATE_CURRENT);
}
}
MainActivity:
package com.example.myapplication;
import android.appwidget.AppWidgetManager;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
public static int number = 15;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.example.myapplication">
<uses-permission android:name="android.permission.VIBRATE"/>
<application
android:allowBackup="true"
android:dataExtractionRules="#xml/data_extraction_rules"
android:fullBackupContent="#xml/backup_rules"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/Theme.MyApplication"
tools:targetApi="31">
<activity
android:name=".MainActivity"
android:exported="true"
android:label="#string/app_name"
android:theme="#style/Theme.MyApplication">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver android:name="com.example.myapplication.WidgetProvider1"
android:label="Tutorial Widget"
android:exported="true"
>
<intent-filter>
<action android:name="android.appwidget.action.APPWIDGET_UPDATE"/>
</intent-filter>
<meta-data
android:name="android.appwidget.provider"
android:resource="#xml/widget_info"
/>
</receiver>
</application>
</manifest>
WidgetInfo:
<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider
xmlns:android="http://schemas.android.com/apk/res/android"
android:minHeight="180dp"
android:minWidth="180dp"
android:initialLayout="#layout/widget_layout"
android:previewImage="#drawable/widget_preview"
android:widgetCategory="home_screen"
android:resizeMode="horizontal|vertical"
>
</appwidget-provider>
WidgeLayout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:theme="#style/Theme.AppCompat.Light"
android:id="#+id/widget_layout"
>
<TextView
android:id="#+id/textView"
android:layout_width="match_parent"
android:layout_height="220dp"
android:layout_centerInParent="true"
android:text="1"
android:textAlignment="center"
android:textSize="150dp"
android:textColor="#color/white"
/>
<Button
android:id="#+id/button3"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="#+id/textView"
android:layout_marginBottom="1dp"
android:text="increase"
android:bottomRightRadius="20dp"
android:bottomLeftRadius="20dp"
android:topLeftRadius="20dp"
android:topRightRadius="20dp"
android:textSize="30dp"
/>
<Button
android:id="#+id/button2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/textView"
android:layout_marginTop="1dp"
android:text="decrease"
android:bottomRightRadius="20dp"
android:bottomLeftRadius="20dp"
android:topLeftRadius="20dp"
android:topRightRadius="20dp"
android:textSize="30dp"
/>
</RelativeLayout>

Android Phone Call Intent

I am trying to make a call with the help of button, compiling time shows no errors but the application stops working as soon as i start the app, both on emulator and my android device. i have also set the permissions in the manifest file. but still :\
please help
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button
android:id="#+id/makeCall"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/make_call" />
</LinearLayout>
MainActivity.java
package com.example.phonecalldemo;
import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public abstract class MainActivity extends Activity implements OnClickListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button startBtn = (Button) findViewById(R.id.makeCall);
startBtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
makeCall();
}
});
}
protected void makeCall() {
Log.i("Make call", "");
Intent phoneIntent = new Intent(Intent.ACTION_CALL);
phoneIntent.setData(Uri.parse("tel:8866158630"));
startActivity(phoneIntent);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.phonecalldemo"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<permission android:name="android.permission.CALL_PHONE"></permission>
<uses-permission android:name="android.permission.CALL_PHONE"></uses-permission>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.phonecalldemo.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

You can't instantiate abstract classes. Remove the 'abstract' from "public abstract class MainActivity", which will give you a different error telling you to implement the onClick method. Once you add that method that your app will launch.

java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.myfirstapp/com.example.myfirstapp.DisplayMessageActivity}

I’m following the android tutorial First App in the link below:
https://developer.android.com/training/basics/firstapp/starting-activity.html
The app can be launched in the emulator but the problem is when I click on the button “send, the application crashed with the message “unfortunately, my fist app has stopped”.
I think I did follow the instructions in the tutorial and can’t figure out where is the problem from.
Logcat send this message:
02-12 16:19:36.031: E/AndroidRuntime(786): java.lang.RuntimeException:
Unable to instantiate activity
ComponentInfo{com.example.myfirstapp/com.example.myfirstapp.DisplayMessageActivity}:
java.lang.NullPointerException
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<EditText android:id="#+id/edit_message"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="#string/edit_message" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_send"
android:onClick="sendMessage" />
</LinearLayout>
MAinActivity.java
package com.example.myfirstapp;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
public class MainActivity extends Activity {
public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
// Do something in response to button
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
activity_display_message.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".DisplayMessageActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>
DisplayMessageActivity.java
package com.example.myfirstapp;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.MenuItem;
import android.widget.TextView;
public class DisplayMessageActivity extends Activity {
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
#SuppressLint("NewApi")
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get the message from the intent
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
// Create the text view
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(message);
// Set the text view as the activity layout
setContentView(textView);
// Make sure we're running on Honeycomb or higher to use ActionBar APIs
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
// Show the Up button in the action bar.
getActionBar().setDisplayHomeAsUpEnabled(true);
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
}
MyFirstApp Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myfirstapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.myfirstapp.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.myfirstapp.DisplayMessageActivity"
android:label="#string/title_activity_display_message"
android:parentActivityName="com.example.myfirstapp.MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.myfirstapp.MainActivity" />
</activity>
</application>
</manifest>
Thank you for your help

I believe the problem is
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
before onCreate(). Intent needs a Context which isn't available until the Activity has been created. Remove those lines since you already have it in onCreate().
Also, when it crashes, post your full logcat because it will tell us, usually, exactly where and what the problem is.

Action listner not working on image in android with draglayout

My xml code :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.my_slide_menu"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.my_slide_menu.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
And java file
package com.example.my_slide_menu;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
import android.support.v4.widget.DrawerLayout;
import android.content.res.Configuration;
import android.graphics.Color;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import com.actionbarsherlock.app.SherlockFragmentActivity;
import com.actionbarsherlock.view.MenuItem;
public class MainActivity extends Activity {
private DrawerLayout drawlayout = null;
ImageView arrow;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
System.out.println("On create");
// drawlayout=(DrawerLayout)findViewById(R.id.drawer_layout);
arrow = (ImageView) findViewById(R.id.arrow);
// getSupportActionBar().setHomeButtonEnabled(true);
// getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// getSupportActionBar().setDisplayShowHomeEnabled(true);
// getSupportActionBar().setDisplayShowTitleEnabled(true);
arrow.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
System.out.println("Touch");
return false;
}
});
}
}
How solve this Proplem.
I want when click on image slider open.But action listner not work on image.
Without drwer click listner working.
I am making a slider menu like face book.
Please help me
My layout file is
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:id="#+id/arrow"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_centerHorizontal="true"
android:src="#drawable/a" />
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<FrameLayout
android:id="#+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<ListView
android:id="#+id/listview_drawer"
android:layout_width="240dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="#111"
android:choiceMode="singleChoice"
android:divider="#android:color/transparent"
android:dividerHeight="0dp" />
</android.support.v4.widget.DrawerLayout>
</RelativeLayout>

Set arrow as ImageButton or add:
android:clickable="true" android:focusable="true"
Hope it helps

Send Data to Wampserver Android

I made a project which must generate a page on entering message, but it is not working for a reason. I am posting the code below.
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="#string/hello_world" />
<EditText
android:id="#+id/edit1"
android:layout_margin="20dp"
android:layout_marginTop="20dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:hint="Write a message"
>
<requestFocus />
</EditText>
<Button
android:id="#+id/button1"
android:layout_gravity="center_horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Enter"
android:onClick="send"
/>
</LinearLayout>
MainActivity.java
package com.example.postapp;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity {
EditText edit1;
Button button1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
edit1 = (EditText) findViewById(R.id.edit1);
button1 = (Button) findViewById(R.id.button1);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void send(View v)
{
String msg = edit1.getText().toString();
if(msg.length()>0)
{ //Toast.makeText(getBaseContext(), "enter length", Toast.LENGTH_SHORT).show();
HttpClient httpc = new DefaultHttpClient();
HttpPost httpost = new HttpPost("http://localhost/demo/server_scripr.php");
//Toast.makeText(getBaseContext(), "enter length0", Toast.LENGTH_SHORT).show();
try
{
List<BasicNameValuePair> vp = new ArrayList<BasicNameValuePair>();
//vp.add(new BasicNameValuePair("id","01"));
vp.add(new BasicNameValuePair("message",msg));
httpost.setEntity(new UrlEncodedFormEntity(vp));
httpc.execute(httpost);
edit1.setText("");
Toast.makeText(getBaseContext(), "Sent", Toast.LENGTH_SHORT).show();
}
catch(Exception e)
{
e.printStackTrace();
}
}
else
{
Toast.makeText(getBaseContext(), "Please enter the field", Toast.LENGTH_SHORT).show();
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.postapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.postapp.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Thanks, help me in finding the solution

The error is most likely within this line of your code:
HttpPost httpost = new HttpPost("http://localhost/demo/server_scripr.php");
Make sure it isn't supposed to be:
/server_script.php