Develop Reference

java.lang.IllegalStateException: Could not execute method of the activity - starting new Activity

I am trying to start a New Activity using Intent but I keep getting java.lang.IllegalStateException: Could not execute method of the activity
What am I doing wrong?
Main Activity
package com.example.wrw;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void clicked(View v)
{
Intent intent = new Intent(this, newact.class);
startActivity(intent);
}
}
newact.java
package com.example.wrw;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
public class newact extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.newlayout);
}
}
act_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:text="#string/hello_world" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Start Act"
android:onClick="clicked"
/>
</LinearLayout>
newlayout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
</LinearLayout>
Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.wrw"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<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>
</application>
</manifest>

In android app, all Activity must be configured in the Manifest.xml file firstly, so you should add newact Activity to your manifest
<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="com.example.wrw.newact"></activity>

Add this to your manifest file
<activity
android:name=".newact"
android:label="#string/title_activity_login">

Replace this to your MainActivity, this may resolve your problem.
Intent intent = new Intent(MainActivity.this, newact.class);
startActivity(intent);
After this, do not forget to add this in your android menifest file,
<activity
android:name=".newact"
android:label="#string/app_name">
</activity>

try this
Intent intent = new Intent(MainActivity.this, newact.class)
and also register newact in manifest file like this
<activity
android:name=".newact"
android:label="#string/app_name">
</activity>

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 app one page to another page not working

Here I done code for 5 buttons like Aboutus,development,carriers,services,contactus.
Here I clicked about us button that shows errors as unfortunately app closed.
Here is my code :
MainActivity.java
public class MainActivity extends Activity {
Button aboutus,development,service,carriers,contactus;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button aboutus=(Button) findViewById(R.id.aboutus);
aboutus.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(),aboutus.class);
startActivity(i);
}
});
}
#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_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: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=".MainActivity" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button
android:id="#+id/aboutus"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="About us"
/>
<Button
android:id="#+id/services"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Services"
/>
<Button
android:id="#+id/development"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Development"
/>
<Button
android:id="#+id/carriers"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Carriers"
/>
<Button
android:id="#+id/contactus"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Contact Us"
/>
</LinearLayout>
</RelativeLayout>
aboutus.java
public class aboutus extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.aboutus);
}
}
aboutus.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="Aboutus Page"/>
</LinearLayout>
AndroidManifest.xml is this correct ?
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.globalinfosoft"
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.globalinfosoft.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= "aboutus"/>
</application>
</manifest>

MainActivity.java
package com.example.a;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.View;
import android.widget.Button;
public class MainActivity extends Activity {
Button aboutus, development, service, carriers, contactus;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button aboutus = (Button) findViewById(R.id.aboutus);
aboutus.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
//Starting a new Intent
Intent nextScreen = new Intent(getApplicationContext(),aboutus.class);
startActivity(nextScreen);
}
});
}
}
Here is Androidmanifest.xml :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.a"
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.a.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.a.aboutus"></activity>
</application>
</manifest>

Instead of v.getContext() use 'getApplicationContext()'.
Intent i = new Intent(getApplicationContext(),aboutus.class);
startActivity(i);

Try this ..
Button aboutus=(Button) findViewById(R.id.aboutus);
aboutus.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(),aboutus.class);
startActivity(i);
}
});

First, you should make sure that you have declared the aboutus acitivity in your AndroidManifest.xml file.
<Activity android:name= "aboutus"/>
Second, you can use
Intent i = new Intent(getApplicationContext(),aboutus.class);
or
Intent i = new Intent(MainActivity.this,aboutus.class);
instead of
Intent i = new Intent(v.getContext(),aboutus.class);

Intent i = new Intent(v.getContext(),aboutus.class);
startActivity(i);
instead of code use following code and instruction:
Intent i = new Intent(MainActivity.this,aboutus.class);
startActivity(i);
you have to declare the About us activity on AndroidManifest.xml like this
<Activity android:name= ".aboutus"/>

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>

android button click not working in program

Hello everybody i have a problem that when i click a button it remains as it is instead of starting new activity. I searched he problem in this site and found some solutions but none of them worked for me so i am writing my problem here.
the xml layout is
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/profile_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/profile" />
<Button
android:id="#+id/create_profile"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:text="#string/create_profile" />
<Button
android:id="#+id/edit_profile"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_toRightOf="#id/create_profile"
android:text="#string/edit_profile" />
<Button
android:id="#+id/delete_profile"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_toRightOf="#id/edit_profile"
android:text="#string/delete_profile" />
<Button
android:id="#+id/activate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_toRightOf="#id/delete_profile"
android:text="#string/activate" />
<ListView
android:id="#id/android:list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_above="#id/create_profile"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_below="#id/profile_title" />
<TextView
android:id="#id/android:empty"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_above="#id/create_profile"
android:layout_below="#id/profile_title"
android:gravity="center_vertical|center_horizontal"
android:text="#string/no_profiles" />
</RelativeLayout>
and the activity is
package com.android.SmartSwitch;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class Profile_Manager extends Activity {
private Button createButton;
private Button editButton;
private Button deleteButton;
private Button activateButton;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.profile);
setUpViews();
}
private void setUpViews() {
createButton = (Button)findViewById(R.id.create_profile);
editButton = (Button)findViewById(R.id.edit_profile);
deleteButton = (Button)findViewById(R.id.delete_profile);
activateButton = (Button)findViewById(R.id.activate);
createButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent intent = new Intent(Profile_Manager.this, Add_Profile.class);
startActivity(intent);
}
});
editButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
}
});
deleteButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
}
});
activateButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
}
});
}
}
androidmanifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.android.SmartSwitch"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:label="#string/app_name"
android:name=".SmartSwitchActivity" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".Location_Manager" android:label="#string/app_name"/>
<activity android:name=".Profile_Manager" android:label="#string/app_name"/>
<activity android:name=".Schedule_Manager" android:label="#string/app_name"/>
<activity android:name=".Location_In_Map" android:label="#string/app_name"/>
<activity android:name=".Add_Profile" android:label="#string/app_name"/>
<uses-library android:name="com.google.android.maps" />
</application>
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
</manifest>
When i click createButton, it doesn't respond

As your Main Activity i.e., Profile_Manager consists of the following Code:
<activity
android:label="#string/app_name"
android:name=".SmartSwitchActivity" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
You have to note if the Profile Manager class is the class which will be launched i.e., if Profile_Manager Class is the First Screen then, you should create the above code in AndroidManifest.xml with the only change as android:name=".Profile_Manager" instead of "SmartSwitchActivity" with the code additionally added for Add_Profile class as follows
<activity
android:label="#string/app_name"
android:name=".Add_Profile" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
I suppose by doing this changes,things will work fine.
If you are not able to understand the above working then,Here is the Link with Perfect Working Example and with available Source Code-Correct Working of Button Click