Develop Reference

Toast and Broadcast receiver doesn't work

Hello i tried many times when i click the button it doesn't show the toast and broadcast receiver
the code attached down there kindly correct my miss takes its run successfully but when click the button nothing happend at all , I tried to edit in activity_main.xml but nothing happend
MainActivity.java
package com.example.myapplication;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
// broadcast a custom intent.
public void broadcastIntent(View view){
Intent intent = new Intent();
intent.setAction("com.myapplication.BOOT_COMPLETED"); sendBroadcast(intent);
}
}
MyReceiver.java
package com.example.myapplication;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;
public class MyReceiver extends BroadcastReceiver{
#Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "Intent Detected.", Toast.LENGTH_LONG).show();
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myapplication">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true">
<activity android:name=".MainActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver android:name="MyReceiver"
android:exported="false">
<intent-filter>
<action android:name="com.myapplication.BOOT_COMPLETED">
</action>
</intent-filter>
</receiver>
</application>
</manifest>
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<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"
tools:context=".MainActivity">
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Example of Broadcast"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:textSize="30dp" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tutorials point "
android:textColor="#ff87ff09"
android:textSize="30dp"
android:layout_above="#+id/imageButton"
android:layout_centerHorizontal="true"
android:layout_marginBottom="40dp" />
<ImageButton
android:id="#+id/imageButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:minWidth="48dp"
android:minHeight="48dp"
tools:ignore="SpeakableTextPresentCheck" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/imageButton"
android:layout_centerHorizontal="true"
android:onClick="broadcastIntent"
android:text="broadcast_intent" />
</RelativeLayout>

I hope this could help
import androidx.appcompat.app.AppCompatActivity;
import android.content.BroadcastReceiver;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends AppCompatActivity {
BroadcastReceiver br;
IntentFilter filter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
br = new MyReceiver();
filter= new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
filter.addAction(Intent.ACTION_AIRPLANE_MODE_CHANGED);
}
public void broadcastIntent(View view){
Intent intent = new Intent();
intent.setAction("com.myapplication.BOOT_COMPLETED");
sendBroadcast(intent);
this.registerReceiver(br, filter);
}
}
also see this link
https://developer.android.com/guide/components/broadcasts

You are using a Manifest-declared receiver. This receiver would get invoked outside from other app or with some system events.
The receiver then becomes a separate entry point into your app which means that the system can start the app and deliver the broadcast if the app is not currently running.
If you want to trigger this receiver within the app you should register this receiver. In your case inside the MainActivity within onCreate or onResume as follows
broadcastReceiver = new MyReceiver ()
Intent filter = new IntentFilter("com.myapplication.BOOT")
registerReceiver(broadcastReceiver, filter)
Also you need to unregister it within onDestroy or onPause
unregisterReceiver(broadcastReceiver)
I guess you should use Context-registered receiver for your use case where you want to send a broadcast within the app. Its almost the same except that you don't need to define it inside the manifest.
More information here

My Activity don't catch a search intent

I'm learning Android to do some projects for the college. I'm doing an app to look data on a web service. But my activity don't catch the search intent (or I thought it). I was following the Android Developer Guide: https://developer.android.com/guide/topics/search/search-dialog. I followed it, but my app doesn't work. I let here my code:
SearchActivity.java
package com.example.javierortiz.pprog2_ac4;
import android.app.SearchManager;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
public class SearchActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search);
Intent intent = getIntent();
if (Intent.ACTION_SEARCH.equals(intent.getAction())){
String asdf = intent.getStringExtra(SearchManager.QUERY);
Log.d("asdfasdfasdf", asdf);
}
}
}
searchable.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
android:label= "#string/app_name"
android:hint = "#string/search_hint">
</PreferenceScreen>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.javierortiz.pprog2_ac4">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".SearchActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<action android:name="android.intent.action.SEARCH" />
<category android:name="android.intent.category.DEFAULT"/>
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<meta-data android:name="android.app.searchable"
android:resource="#xml/searchable" />
</activity>
</application>
</manifest>
activity_search.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".SearchActivity">
<SearchView
android:id="#+id/search"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
Thank you in advance

If you want to implement a search view listener try:
SearchView search = findViewById(R.id.search);
search.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
#Override
public boolean onQueryTextChange(String newText) {
return false;
}
#Override
public boolean onQueryTextSubmit(String query) {
Log.d("onQueryTextChange", "query" + query);
// Do your task here
return false;
}
});

Cant start new activity. It keeps crashing

When pressing the button, new activity should open but app instantly crashes. I have searched for answer and making a few adjustments to my code and only thing i dont know how to do is Manifest, can u help me with that?
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="Starting.Programm"
android:versionCode="1"
android:versionName="1.0">
<application android:label="#string/app_name"
android:icon="#drawable/ic_launcher">
<activity android:name="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="InformationActivity"
android:label="#string/app_name"
>
</activity>
</application>
MainActivity:
package Starting.Programm;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends InformationActivity
{
/** Called when the activity is first created. */
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void startJourney(View view) {
Intent intent = new Intent(this, InformationActivity.class);
startActivity(intent);
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<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"
tools:context=".MainActivity"
>
<Button android:id="#+id/button_StartApp"
android:layout_width="100dp"
android:layout_height="60dp"
android:text="#string/button_StartApp"
android:layout_gravity="center"
android:layout_marginTop="70dp"
android:layout_marginLeft="115dp"
android:onClick="startJourney"
/>
</LinearLayout>
And next activity which should be opening
package Starting.Programm;
import android.app.Activity;
import android.os.Bundle;
class InformationActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.information);
}
}

<activity> android:name=".InformationActivity" </activity>
Remove android:label="#string/app_name" too. I don't think it is needed.

Add dot to end of pacakager name
package="Starting.Programm."

How do I get a selection of activities for a single activity using intent?

I've started learning programming for Android and the tutorial I'm following says that if I add 2 activities to the manifest xml with the same intent I should get a dialog that makes me select one of them, but it doesn't. My Android version is 2.3.
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.frisodenijs.usingintent" >
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".main"
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=".SecondActivity"
android:label="#string/title_activity_second" >
<intent-filter>
<action android:name="com.frisodenijs.SecondActivity" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<activity
android:name=".ThirdActivity"
android:label="Third Activity">
<intent-filter>
<action android:name="com.frisodenijs.SecondActivity" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>
</manifest>
Main activity:
package com.frisodenijs.usingintent;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.content.Intent;
public class main extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void onClick(View view) {
startActivity(new Intent(main.this, SecondActivity.class));
}
}
Second activity:
package com.frisodenijs.usingintent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
public class SecondActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
}
}
Main 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:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context=".main">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="To second button"
android:onClick="onClick"/>
</RelativeLayout>
Second Activity 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:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.frisodenijs.usingintent.SecondActivity">
<TextView
android:text="This is the second activity"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>

Replace your onClick with this…
public void onClick(View view) {
startActivity(new Intent("com.frisodenijs.SecondActivity"));
}

Android application crases when switching activity

I have a problem with an Android aplication. When I try to swich from main activity (PretvornikValut) to another one (Pretvornik) via buttun I get the "Unfortunately aplication stopped working" error. Can anyone help?
PretvornikValut.java
package pretvornik.valut;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
public class PretvornikValut extends Activity implements OnClickListener
{
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
View gumbPretvori = findViewById(R.id.gumb_pretvornik);
gumbPretvori.setOnClickListener(this);
View gumbTecaji = findViewById(R.id.gumb_tecaji);
gumbTecaji.setOnClickListener(this);
}
public void sendMessage(View view) {
Intent intent = new Intent(this, Pretvornik.class);
startActivity(intent);
}
public void onClick(View v) {
switch (v.getId()) {
case R.id.gumb_pretvornik:
Intent i = new Intent(this, Pretvornik.class);
//i.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(i);
break;
case R.id.gumb_tecaji:
Intent tecaj = new Intent(this, Tecaji.class);
tecaj.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(tecaj);
break;
}
}
}
Pretvornik java
package pretvornik.valut;
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.view.WindowManager;
/**
*
* #author FAKS
*/
public class Pretvornik extends Activity {
/**
* Called when the activity is first created.
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.pretvornik);
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#99CCCC"
>
<Button
android:id="#+id/gumb_pretvornik"
android:layout_width="100dp"
android:layout_height="50dp"
android:layout_alignParentLeft="true"
android:layout_alignParentBottom="true"
android:text="Pretvornik"
/>
<Button
android:id="#+id/gumb_tecaji"
android:layout_width="100dp"
android:layout_height="50dp"
android:layout_toRightOf="#+id/OK"
android:layout_alignParentBottom="true"
android:text="Izpis tecajev"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Izberi zeljeno opcijo"
/>
</LinearLayout>
pretvornik.xml
<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#99CCCC"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="glavni program"
/>
</LinearLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="pretvornik.valut"
android:versionCode="1"
android:versionName="1.0">
<application android:label="#string/app_name" android:icon="#drawable/ic_launcher">
<activity android:name="PretvornikValut"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<activity
android:name="Pretvornik"
android:label="#string/Pretvornik_valut" >
<meta-data
android:name="PretvornikValut"
/>
</activity>
<activity
android:name="Tecaji"
android:label="#string/Izpis_tecajev" >
<meta-data
android:name="PretvornikValut"
/>
</activity>
</activity>
</application>
</manifest>

Change your manifest xml,
add action for your activities
action android:name="android.intent.action.ACTIVITY"
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="pretvornik.valut"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="15" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="PretvornikValut"
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="Pretvornik"
android:label="#string/hello_world" >
<action android:name="android.intent.action.ACTIVITY" />
</activity>
<activity
android:name="Tecaji"
android:label="#string/hello_world" >
<action android:name="android.intent.action.ACTIVITY" />
</activity>
</application>
</manifest>