Android Using a button to start new activity

Question

How to start a new activity using a button in Android?

This is my code for button "A" in my app :

final TextView parkAvaliableA = (TextView) findViewById(R.id.parkASlot);
    parkAvaliableA.setText("Available Slot : " + SlotA.available_slot);
    Button buttonA = (Button) findViewById(R.id.parkA);
    buttonA.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            if(SlotA.available_slot == 0)
            {
                Toast.makeText(getApplicationContext(), 
                        "Parking slot A is full", 
                        Toast.LENGTH_SHORT).show();
            }
            else
            {
                SlotA.available_slot -= 1;
                db.updateSlot(new ParkingSlot());
            }
            parkAvaliableA.setText("Available Slot : " + SlotA.available_slot);
            Intent myIntent = new Intent(MainMap.this, ParkA.class);

            MainMap.this.startActivity(myIntent);
        }

    });

When I press the button, the app crashed. Is that MainMap.this.startActivity(myIntent); wrong?

Update :

Here's my manifest :

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

<uses-permission android:name="android.permission.NFC" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" />
<uses-permission android:name="android.permission.INTERNET" />

<uses-feature
    android:name="android.hardware.nfc"
    android:required="true" />

<uses-sdk
    android:minSdkVersion="14"
    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>

    <activity
        android:name=".MainMap"
        android:label="@string/app_name" >

        <intent-filter>
            <action android:name="android.nfc.action.NDEF_DISCOVERED" />
            <category android:name="android.intent.category.DEFAULT" />
            <data android:mimeType="application/com.km.parkit" />
        </intent-filter>

        </activity>

    <activity
        android:name="com.km.parkit.parka"
        android:label="@string/app_name" />

    <activity
        android:name="com.km.parkit.parkb"
        android:label="@string/app_name" />

    <activity
        android:name="com.km.parkit.parkc"
        android:label="@string/app_name" />

    <activity
        android:name="com.km.parkit.parkd"
        android:label="@string/app_name" />


    <!-- Google Maps API Key -->
<meta-data
    android:name="com.google.android.maps.v2.API_KEY"
    android:value="AIzaSyBf-0hUDrDTK-NOveZrnT8wec5TTTLqjAw" />

 <meta-data 
     android:name="com.google.android.gms.version"
     android:value="@integer/google_play_services_version" />

</application>



</manifest>

I've declared the other classes in the app, is there something missing?

Answer 1

Change your Activity name in manifiest to

<activity
        android:name="com.km.parkit.ParkA"
        android:label="@string/app_name" />

Instead of com.km.parkit.parka

It is case sensitive.