Android activity crashes on button click

Question

When I click the button to go to the next activity, my app crashes. I don't know if it's an issue with my Game class, Menu class, the game layout or the Manifest. I assume it's the manifest though.

I've tried tons of different ways to solve the problem. I changed the name of the intent in the manifest, I changed the way I call the activity in the java class...but nothing worked.

Can someone please help?

I think there's an issue with the way I'm declaring the activities in the manifest but I am not sure.

Here is the code:

Menu.java:

package com.example.hello_world;

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 Menu extends Activity implements OnClickListener {

Button clickToStart;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.menu_activity);
    clickToStart = (Button) findViewById(R.id.click);
    clickToStart.setOnClickListener(this);

}


@Override
public void onClick(View v) {
    Intent openGame = new Intent(getApplicationContext(), Game.class);
    startActivity(openGame);

}

}

Game.java:

package com.example.hello_world;
import android.app.Activity;
import android.os.Bundle;

public class Game extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.game_activity);
}   
}

Android Manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.hello_world"
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=".Menu"
        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=".Game"
        android:label="@string/app_name" 
        android:screenOrientation="landscape">
        <intent-filter>
            <action android:name="com.example.hello_world.GAME" />

            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </activity>

</application>

game layout:

<?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=".Game" >

<Button
    android:id="@+id/button1"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:layout_marginTop="18dp"
    android:text="a" />

<Button
    android:id="@+id/button2"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button1"
    android:layout_alignBottom="@+id/button1"
    android:layout_toRightOf="@+id/button1"
    android:text="b" />

<Button
    android:id="@+id/button4"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button3"
    android:layout_alignBottom="@+id/button3"
    android:layout_toRightOf="@+id/button3"
    android:text="c" />

<Button
    android:id="@+id/button5"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button4"
    android:layout_alignBottom="@+id/button4"
    android:layout_toRightOf="@+id/button4"
    android:text="d" />

<Button
    android:id="@+id/button6"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignParentLeft="true"
    android:layout_alignRight="@+id/button1"
    android:layout_below="@+id/button1"
    android:text="e" />

<Button
    android:id="@+id/button7"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button6"
    android:layout_alignBottom="@+id/button6"
    android:layout_alignRight="@+id/button2"
    android:layout_toRightOf="@+id/button6"
    android:text="f" />

<Button
    android:id="@+id/button8"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_below="@+id/button2"
    android:layout_toRightOf="@+id/button2"
    android:text="g" />

<Button
    android:id="@+id/button3"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_above="@+id/button7"
    android:layout_toRightOf="@+id/button2"
    android:text="h" />

<Button
    android:id="@+id/button9"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button8"
    android:layout_alignBottom="@+id/button8"
    android:layout_toLeftOf="@+id/button5"
    android:text="i" />

<Button
    android:id="@+id/button10"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_below="@+id/button4"
    android:layout_toRightOf="@+id/button4"
    android:text="j" />

<Button
    android:id="@+id/button11"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignParentLeft="true"
    android:layout_alignRight="@+id/button6"
    android:layout_below="@+id/button6"
    android:text="k" />

<Button
    android:id="@+id/button13"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignLeft="@+id/button8"
    android:layout_below="@+id/button8"
    android:text="l" />

<Button
    android:id="@+id/button14"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button12"
    android:layout_alignBottom="@+id/button12"
    android:layout_toRightOf="@+id/button13"
    android:text="m" />

<Button
    android:id="@+id/button16"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignParentLeft="true"
    android:layout_alignRight="@+id/button21"
    android:layout_below="@+id/button12"
    android:text="n" />

<Button
    android:id="@+id/button17"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_below="@+id/button12"
    android:layout_toLeftOf="@+id/button18"
    android:layout_toRightOf="@+id/button16"
    android:text="o" />

<Button
    android:id="@+id/button19"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button18"
    android:layout_alignBottom="@+id/button18"
    android:layout_toLeftOf="@+id/button15"
    android:text="p" />

<Button
    android:id="@+id/button20"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button17"
    android:layout_alignBottom="@+id/button17"
    android:layout_alignLeft="@+id/button10"
    android:text="q" />

<Button
    android:id="@+id/button18"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_below="@+id/button14"
    android:layout_toLeftOf="@+id/button14"
    android:text="r" />

<Button
    android:id="@+id/button15"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignLeft="@+id/button10"
    android:layout_below="@+id/button10"
    android:text="t" />

<Button
    android:id="@+id/button21"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignParentLeft="true"
    android:layout_alignRight="@+id/button6"
    android:layout_below="@+id/button16"
    android:text="u" />

<Button
    android:id="@+id/button22"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button21"
    android:layout_alignBottom="@+id/button21"
    android:layout_alignLeft="@+id/button17"
    android:layout_alignRight="@+id/button17"
    android:text="v" />

<Button
    android:id="@+id/button23"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button22"
    android:layout_alignBottom="@+id/button22"
    android:layout_alignLeft="@+id/button18"
    android:text="w" />

<Button
    android:id="@+id/button24"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button23"
    android:layout_alignBottom="@+id/button23"
    android:layout_toRightOf="@+id/button23"
    android:text="x" />

<Button
    android:id="@+id/button25"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignBaseline="@+id/button24"
    android:layout_alignBottom="@+id/button24"
    android:layout_alignLeft="@+id/button20"
    android:text="y" />

<Button
    android:id="@+id/button12"
    android:layout_width="@string/size"
    android:layout_height="@string/size"
    android:layout_alignRight="@+id/button7"
    android:layout_below="@+id/button6"
    android:layout_toRightOf="@+id/button6"
    android:text="s" />

Error Log:

Answer 1

You currently have all the layout dimensions for your buttons set to String references. Layout dimensions need to be integers - you can store these in dimens.xml like so:

<dimen name="size">16dp</dimen> <!-- change size to what you need -->

Then, use layout_width="@dimen/size" for your views (and layout_height as well).

Answer 2

You should be using the Activity context to launch an Activity instead of Application Context.

Since Activity extends Context, you can use the this keyword to reference context.

@Override
public void onClick(View v) {
    Intent openGame = new Intent(this, Game.class);
    startActivity(openGame);

}

If you really want to use application context (which I do not think you meant to do), then I believe you would have to start the Activity in a different way, in a new task.

Answer 3

Remove the intent filter for Game Activity and make sure the class is located in the right package

    <intent-filter>
        <action android:name="com.example.hello_world.GAME" />
        <category android:name="android.intent.category.DEFAULT" />

And this is not the right way to set the height and width of buttons inside the game layout: Correct them.

<Button
android:id="@+id/button2"
android:layout_width="@string/size"
android:layout_height="@string/size"
android:text="b" />

Regards