效果圖：

MainActivity程式碼

public class MainActivity extends Activity {
private Button bt;


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bt = (Button)findViewById(R.id.button1);
bt.setOnClickListener(new OnClickListener(){


@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Intent intent = new Intent();
intent.setClass(MainActivity.this, DialogActivity.class);
startActivity(intent);
}

});

}


@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;
}


}

DialogActivity程式碼

public class DialogActivity extends Activity {


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dialog);
getWindow().setLayout(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.dialog, menu);
return true;
}


}

佈局檔案：

MainActivity的佈局檔案簡單就不貼了

activity_dialog.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=".DialogActivity" 
    android:background="@drawable/passion_half_bg">


    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:text="我偽裝成彈出框了！" />


</RelativeLayout>

dialog.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android" >


    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="@string/action_settings"/>


</menu>

main.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android" >


    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        android:showAsAction="never"
        android:title="@string/action_settings"/>


</menu>

dimens.xml

<resources>


    <!-- Default screen margins, per the Android Design guidelines. -->
    <dimen name="activity_horizontal_margin">16dp</dimen>
    <dimen name="activity_vertical_margin">16dp</dimen>


</resources>

styles.xml

<resources>


    <!--
        Base application theme, dependent on API level. This theme is replaced
        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
    -->
    <style name="AppBaseTheme" parent="android:Theme.Light">
        <!--
            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        -->
    </style>


    <!-- Application theme. -->
    <style name="AppTheme" parent="AppBaseTheme">
        <!-- All customizations that are NOT specific to a particular API-level can go here. -->
    </style>
   <!-- Test demo  -->
      <style name="DialogStyle" parent="@android:style/Theme.Dialog">
        <item name="android:windowIsFloating">true</item>
        <item name="android:windowIsTranslucent">true</item>
        <item name="android:windowNoTitle">true</item>
        <item name="android:windowBackground">@android:color/transparent</item>
        <item name="android:backgroundDimAmount">0.3</item>
       <item name="android:windowAnimationStyle">@null</item>
    </style>
</resources>

MainFest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.fullscreendialogdemo"
    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.fullscreendialogdemo.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.fullscreendialogdemo.DialogActivity"
            android:label="@string/title_activity_dialog" 
            android:theme="@style/DialogStyle" >
        </activity>
    </application>


</manifest>