Android Activity as a dialog

To start activity as dialog I defined it like this in AndroidManifest.xml:

<activity android:theme="@android:style/Theme.Dialog" />

Use this property inside your activity tag to avoid that your Dialog appears in the recently used apps list

android:excludeFromRecents="true"

If you want to stop your dialog / activity from being destroyed when the user clicks outside of the dialog:

After setContentView() in your Activity use:

this.setFinishOnTouchOutside(false);

Now when I call startActivity() it displays as a dialog, with the previous activity shown when the user presses the back button.

Note that if you are using ActionBarActivity (or AppCompat theme), you'll need to use @style/Theme.AppCompat.Dialog instead.

Use this code so that the dialog activity won't be closed when the user touches outside the dialog box:

this.setFinishOnTouchOutside(false);

requires API level 11

You can define this style in values/styles.xml to perform a more former Splash :

   <style name="Theme.UserDialog" parent="android:style/Theme.Dialog">
        <item name="android:windowFrame">@null</item>
        <item name="android:windowIsFloating">true</item>
        <item name="android:windowIsTranslucent">true</item>
        <item name="android:windowNoTitle">true</item>
        <item name="android:background">@android:color/transparent</item>
        <item name="android:windowBackground">@drawable/trans</item>
    </style>

And use it AndroidManifest.xml:

   <activity android:name=".SplashActivity"
          android:configChanges="orientation"
          android:screenOrientation="sensor"
          android:theme="@style/Theme.UserDialog">

If you need Appcompat Version

style.xml

    <!-- Base application theme. -->
    <style name="AppDialogTheme" parent="Theme.AppCompat.Light.Dialog">
        <!-- Customize your theme here. -->
        <item name="windowActionBar">false</item>
        <item name="android:windowNoTitle">true</item>
    </style>

yourmanifest.xml

    <activity
          android:name=".MyActivity"
          android:label="@string/title"
          android:theme="@style/AppDialogTheme">
    </activity>