اتصال اکتیویتی ها به یکدیگر

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

    <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:label="Second Activity"
            android:name=".SecondActivity">
            <intent-filter>
                <action  android:name="com.PRG.SecondActivity"/>
                <category android:name="android.intent.category.DEFAULT"/>
            </intent-filter>
        </activity>
    </application>

</manifest>

<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: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="com.PRG.intent.MainActivity" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Second Activity" />

</LinearLayout>

package com.PRG.intent;

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

public class SecondActivity extends Activity {
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.secondactivity);
    }

}

<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="com.PRG.intent.MainActivity" >

    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Display Second Activity"
        android:onClick="OnClick" />

</RelativeLayout>

package com.PRG.intent;

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.main);
    }
    public void onClick(View view){
        startActivity(new Intent("com.PRG.SecondActivity"));
    }

}

 <activity
            android:label="Second Activity"
            android:name=".SecondActivity">
            <intent-filter>
                <action  android:name="com.PRG.SecondActivity"/>
                <category android:name="android.intent.category.DEFAULT"/>
            </intent-filter>
        </activity>

public void onClick(View view){
        startActivity(new Intent("com.PRG.SecondActivity"));
    }

startActivity(new Intent(this, SecondActivity.class));