CODEWITHSUNDEEP
androidviewandroid-intent
Buksy
Buksy

Reputation: 12228

New intent, how to link to my class?

I'm beginner in Android (and java), and I'm just playing around and want to create new View after clicking a button. Here is my code so far:

Main class

package myTests.homeSpace;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class TestsActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button button1 = (Button) findViewById(R.id.button1);
        button1.setOnClickListener( new OnClickListener()
        {
            public void onClick(View v)
            {
                Intent myIntent = new Intent(TestsActivity.this, screen1.class);
                startActivity(myIntent);
            }
        });
    }
}

Class to run after clicking button

package myTests.homeSpace;

import android.app.Activity;
import android.os.Bundle;

public class screen1 extends Activity {
    @Override
    public void onCreate(Bundle SavedBundleInstance)
    {
        super.onCreate(SavedBundleInstance);
        setContentView(R.layout.screen1);
    }
}

The problem is, after hitting button I got "Unforunately, Tests has stopped" error. ("Tests" is application name). I know (or guess) the problem is in this line Intent myIntent = new Intent(TestsActivity.this, screen1.class); I guess my reference to class screen1 is wrong somehow, but I have no idea why. There are no compilation errors nor warnings, layout .xmls shouldn't be wrong.

Could any of you please advice me any solution?

EDIT

MANIFEST

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="myTests.homeSpace"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".TestsActivity"
            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>

CONSOLE OUTPUT

[2012-06-20 19:56:21 - ddms] null
java.lang.NullPointerException
    at com.android.ddmlib.JdwpPacket.writeAndConsume(JdwpPacket.java:213)
    at com.android.ddmlib.Client.sendAndConsume(Client.java:575)
    at com.android.ddmlib.HandleHello.sendHELO(HandleHello.java:142)
    at com.android.ddmlib.HandleHello.sendHelloCommands(HandleHello.java:65)
    at com.android.ddmlib.Client.getJdwpPacket(Client.java:672)
    at com.android.ddmlib.MonitorThread.processClientActivity(MonitorThread.java:317)
    at com.android.ddmlib.MonitorThread.run(MonitorThread.java:263)

Upvotes: 0

Views: 1166

Answers (3)

Arun George
Arun George

Reputation: 18592

Declare your second activity in the Manifest.xml as:

<activity
        android:name=".screen1">
    </activity>

Just below the declaration of your first activity.

Upvotes: 0

Kgrover
Kgrover

Reputation: 2116

I agree, not declaring the activity in your Manifest file (AndroidManifest.xml) is most likely your problem. See the android developer page on activities for more information. Here is the relevant description:

Declares an activity (an Activity subclass) that implements part of the application's visual user interface. All activities must be represented by elements in the manifest file. Any that are not declared there will not be seen by the system and will never be run.

I just posted this so you would have more space to research on your own.

Upvotes: 2

K-ballo
K-ballo

Reputation: 81349

I bet if you read the crash log somewhere in there says did you forget to declare this activity in the Manifest?

Upvotes: 4

Related Questions