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.

If your activity is being rendered as a dialog, simply add a button to your activity's xml,

<Button
    android:id="@+id/close_button"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Dismiss" />

Then attach a click listener in your Activity's Java code. In the listener, simply call finish()

Button close_button = (Button) findViewById(R.id.close_button);
close_button.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        finish();
    }
});

That should dismiss your dialog, returning you to the calling activity.

Create activity as dialog, Here is Full Example

1. AndroidManife.xml

   <activity android:name=".appview.settings.view.DialogActivity" android:excludeFromRecents="true" android:theme="@style/Theme.AppCompat.Dialog"/>

2. DialogActivity.kt

   class DialogActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
       super.onCreate(savedInstanceState)
       setContentView(R.layout.activity_dialog)
       this.setFinishOnTouchOutside(true)
   
       btnOk.setOnClickListener {
         finish()
       }
     }
   }
   

3. activity_dialog.xml

   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:app="http://schemas.android.com/apk/res-auto"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"
   android:background="#0072ff"
   android:gravity="center"
   android:orientation="vertical">
   
   <LinearLayout
       android:layout_width="@dimen/_300sdp"
       android:layout_height="wrap_content"
       android:gravity="center"
       android:orientation="vertical">
   
       <TextView
           android:id="@+id/txtTitle"
           style="@style/normal16Style"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:gravity="center"
           android:paddingTop="20dp"
           android:paddingBottom="20dp"
           android:text="Download"
           android:textColorHint="#FFF" />
   
       <View
           android:id="@+id/viewDivider"
           android:layout_width="match_parent"
           android:layout_height="2dp"
           android:background="#fff"
           android:backgroundTint="@color/white_90"
           app:layout_constraintBottom_toBottomOf="@id/txtTitle" />
   
       <TextView
           style="@style/normal14Style"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:gravity="center"
           android:paddingTop="20dp"
           android:paddingBottom="20dp"
           android:text="Your file is download"
           android:textColorHint="#FFF" />
   
   
       <Button
           android:id="@+id/btnOk"
           style="@style/normal12Style"
           android:layout_width="100dp"
           android:layout_height="40dp"
           android:layout_marginBottom="20dp"
           android:background="@drawable/circle_corner_layout"
           android:text="Ok"
           android:textAllCaps="false" />
       </LinearLayout>
   
     </LinearLayout>
   

Set the theme in your android manifest file.

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

And set the dialog state on touch to finish.

this.setFinishOnTouchOutside(false);

Some times you can get the Exception which is given below

Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.

So for resolving you can use simple solution

add theme of you activity in manifest as dialog for appCompact.

android:theme="@style/Theme.AppCompat.Dialog"

It can be helpful for somebody.