Android APIs
public class

DialogFragment

extends Fragment
implements DialogInterface.OnCancelListener DialogInterface.OnDismissListener
java.lang.Object
   ↳ android.app.Fragment
     ↳ android.app.DialogFragment
Known Direct Subclasses
Known Indirect Subclasses

Class Overview

A fragment that displays a dialog window, floating on top of its activity's window. This fragment contains a Dialog object, which it displays as appropriate based on the fragment's state. Control of the dialog (deciding when to show, hide, dismiss it) should be done through the API here, not with direct calls on the dialog.

Implementations should override this class and implement onCreateView(LayoutInflater, ViewGroup, Bundle) to supply the content of the dialog. Alternatively, they can override onCreateDialog(Bundle) to create an entirely custom dialog, such as an AlertDialog, with its own content.

Topics covered here:

  1. Lifecycle
  2. Basic Dialog
  3. Alert Dialog
  4. Selecting Between Dialog or Embedding

Lifecycle

DialogFragment does various things to keep the fragment's lifecycle driving it, instead of the Dialog. Note that dialogs are generally autonomous entities -- they are their own window, receiving their own input events, and often deciding on their own when to disappear (by receiving a back key event or the user clicking on a button).

DialogFragment needs to ensure that what is happening with the Fragment and Dialog states remains consistent. To do this, it watches for dismiss events from the dialog and takes care of removing its own state when they happen. This means you should use show(FragmentManager, String) or show(FragmentTransaction, String) to add an instance of DialogFragment to your UI, as these keep track of how DialogFragment should remove itself when the dialog is dismissed.

Basic Dialog

The simplest use of DialogFragment is as a floating container for the fragment's view hierarchy. A simple implementation may look like this:

public static class MyDialogFragment extends DialogFragment {
    int mNum;

    /**
     * Create a new instance of MyDialogFragment, providing "num"
     * as an argument.
     */
    static MyDialogFragment newInstance(int num) {
        MyDialogFragment f = new MyDialogFragment();

        // Supply num input as an argument.
        Bundle args = new Bundle();
        args.putInt("num", num);
        f.setArguments(args);

        return f;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mNum = getArguments().getInt("num");

        // Pick a style based on the num.
        int style = DialogFragment.STYLE_NORMAL, theme = 0;
        switch ((mNum-1)%6) {
            case 1: style = DialogFragment.STYLE_NO_TITLE; break;
            case 2: style = DialogFragment.STYLE_NO_FRAME; break;
            case 3: style = DialogFragment.STYLE_NO_INPUT; break;
            case 4: style = DialogFragment.STYLE_NORMAL; break;
            case 5: style = DialogFragment.STYLE_NORMAL; break;
            case 6: style = DialogFragment.STYLE_NO_TITLE; break;
            case 7: style = DialogFragment.STYLE_NO_FRAME; break;
            case 8: style = DialogFragment.STYLE_NORMAL; break;
        }
        switch ((mNum-1)%6) {
            case 4: theme = android.R.style.Theme_Holo; break;
            case 5: theme = android.R.style.Theme_Holo_Light_Dialog; break;
            case 6: theme = android.R.style.Theme_Holo_Light; break;
            case 7: theme = android.R.style.Theme_Holo_Light_Panel; break;
            case 8: theme = android.R.style.Theme_Holo_Light; break;
        }
        setStyle(style, theme);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_dialog, container, false);
        View tv = v.findViewById(R.id.text);
        ((TextView)tv).setText("Dialog #" + mNum + ": using style "
                + getNameForNum(mNum));

        // Watch for button clicks.
        Button button = (Button)v.findViewById(R.id.show);
        button.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                // When button is clicked, call up to owning activity.
                ((FragmentDialog)getActivity()).showDialog();
            }
        });

        return v;
    }
}

An example showDialog() method on the Activity could be:

void showDialog() {
    mStackLevel++;

    // DialogFragment.show() will take care of adding the fragment
    // in a transaction.  We also want to remove any currently showing
    // dialog, so make our own transaction and take care of that here.
    FragmentTransaction ft = getFragmentManager().beginTransaction();
    Fragment prev = getFragmentManager().findFragmentByTag("dialog");
    if (prev != null) {
        ft.remove(prev);
    }
    ft.addToBackStack(null);

    // Create and show the dialog.
    DialogFragment newFragment = MyDialogFragment.newInstance(mStackLevel);
    newFragment.show(ft, "dialog");
}

This removes any currently shown dialog, creates a new DialogFragment with an argument, and shows it as a new state on the back stack. When the transaction is popped, the current DialogFragment and its Dialog will be destroyed, and the previous one (if any) re-shown. Note that in this case DialogFragment will take care of popping the transaction of the Dialog is dismissed separately from it.

Alert Dialog

Instead of (or in addition to) implementing onCreateView(LayoutInflater, ViewGroup, Bundle) to generate the view hierarchy inside of a dialog, you may implement onCreateDialog(Bundle) to create your own custom Dialog object.

This is most useful for creating an AlertDialog, allowing you to display standard alerts to the user that are managed by a fragment. A simple example implementation of this is:

public static class MyAlertDialogFragment extends DialogFragment {

    public static MyAlertDialogFragment newInstance(int title) {
        MyAlertDialogFragment frag = new MyAlertDialogFragment();
        Bundle args = new Bundle();
        args.putInt("title", title);
        frag.setArguments(args);
        return frag;
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        int title = getArguments().getInt("title");

        return new AlertDialog.Builder(getActivity())
                .setIcon(R.drawable.alert_dialog_icon)
                .setTitle(title)
                .setPositiveButton(R.string.alert_dialog_ok,
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int whichButton) {
                            ((FragmentAlertDialog)getActivity()).doPositiveClick();
                        }
                    }
                )
                .setNegativeButton(R.string.alert_dialog_cancel,
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int whichButton) {
                            ((FragmentAlertDialog)getActivity()).doNegativeClick();
                        }
                    }
                )
                .create();
    }
}

The activity creating this fragment may have the following methods to show the dialog and receive results from it:

void showDialog() {
    DialogFragment newFragment = MyAlertDialogFragment.newInstance(
            R.string.alert_dialog_two_buttons_title);
    newFragment.show(getFragmentManager(), "dialog");
}

public void doPositiveClick() {
    // Do stuff here.
    Log.i("FragmentAlertDialog", "Positive click!");
}

public void doNegativeClick() {
    // Do stuff here.
    Log.i("FragmentAlertDialog", "Negative click!");
}

Note that in this case the fragment is not placed on the back stack, it is just added as an indefinitely running fragment. Because dialogs normally are modal, this will still operate as a back stack, since the dialog will capture user input until it is dismissed. When it is dismissed, DialogFragment will take care of removing itself from its fragment manager.

Selecting Between Dialog or Embedding

A DialogFragment can still optionally be used as a normal fragment, if desired. This is useful if you have a fragment that in some cases should be shown as a dialog and others embedded in a larger UI. This behavior will normally be automatically selected for you based on how you are using the fragment, but can be customized with setShowsDialog(boolean).

For example, here is a simple dialog fragment:

public static class MyDialogFragment extends DialogFragment {
    static MyDialogFragment newInstance() {
        return new MyDialogFragment();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.hello_world, container, false);
        View tv = v.findViewById(R.id.text);
        ((TextView)tv).setText("This is an instance of MyDialogFragment");
        return v;
    }
}

An instance of this fragment can be created and shown as a dialog:

void showDialog() {
    // Create the fragment and show it as a dialog.
    DialogFragment newFragment = MyDialogFragment.newInstance();
    newFragment.show(getFragmentManager(), "dialog");
}

It can also be added as content in a view hierarchy:

FragmentTransaction ft = getFragmentManager().beginTransaction();
DialogFragment newFragment = MyDialogFragment.newInstance();
ft.add(R.id.embedded, newFragment);
ft.commit();

Summary

[Expand]
Inherited XML Attributes
From class android.app.Fragment
Constants
int STYLE_NORMAL Style for setStyle(int, int): a basic, normal dialog.
int STYLE_NO_FRAME Style for setStyle(int, int): don't draw any frame at all; the view hierarchy returned by onCreateView(LayoutInflater, ViewGroup, Bundle) is entirely responsible for drawing the dialog.
int STYLE_NO_INPUT Style for setStyle(int, int): like STYLE_NO_FRAME, but also disables all input to the dialog.
int STYLE_NO_TITLE Style for setStyle(int, int): don't include a title area.
[Expand]
Inherited Constants
From interface android.content.ComponentCallbacks2
Public Constructors
DialogFragment()
Public Methods
void dismiss()
Dismiss the fragment and its dialog.
void dismissAllowingStateLoss()
void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args)
Print the Fragments's state into the given stream.
Dialog getDialog()
boolean getShowsDialog()
Return the current value of setShowsDialog(boolean).
int getTheme()
boolean isCancelable()
Return the current value of setCancelable(boolean).
void onActivityCreated(Bundle savedInstanceState)
Called when the fragment's activity has been created and this fragment's view hierarchy instantiated.
void onAttach(Activity activity)
This method is deprecated. Use onAttach(Context) instead.
void onCancel(DialogInterface dialog)
This method will be invoked when the dialog is canceled.
void onCreate(Bundle savedInstanceState)
Called to do initial creation of a fragment.
Dialog onCreateDialog(Bundle savedInstanceState)
Override to build your own custom Dialog container.
void onDestroyView()
Remove dialog.
void onDetach()
Called when the fragment is no longer attached to its activity.
void onDismiss(DialogInterface dialog)
This method will be invoked when the dialog is dismissed.
void onSaveInstanceState(Bundle outState)
Called to ask the fragment to save its current dynamic state, so it can later be reconstructed in a new instance of its process is restarted.
void onStart()
Called when the Fragment is visible to the user.
void onStop()
Called when the Fragment is no longer started.
void setCancelable(boolean cancelable)
Control whether the shown Dialog is cancelable.
void setShowsDialog(boolean showsDialog)
Controls whether this fragment should be shown in a dialog.
void setStyle(int style, int theme)
Call to customize the basic appearance and behavior of the fragment's dialog.
int show(FragmentTransaction transaction, String tag)
Display the dialog, adding the fragment using an existing transaction and then committing the transaction.
void show(FragmentManager manager, String tag)
Display the dialog, adding the fragment to the given FragmentManager.
[Expand]
Inherited Methods
From class android.app.Fragment
From class java.lang.Object
From interface android.content.ComponentCallbacks2
From interface android.view.View.OnCreateContextMenuListener
From interface android.content.DialogInterface.OnCancelListener
From interface android.content.DialogInterface.OnDismissListener
From interface android.content.ComponentCallbacks

Constants

public static final int STYLE_NORMAL

Added in API level 11

Style for setStyle(int, int): a basic, normal dialog.

Constant Value: 0 (0x00000000)

public static final int STYLE_NO_FRAME

Added in API level 11

Style for setStyle(int, int): don't draw any frame at all; the view hierarchy returned by onCreateView(LayoutInflater, ViewGroup, Bundle) is entirely responsible for drawing the dialog.

Constant Value: 2 (0x00000002)

public static final int STYLE_NO_INPUT

Added in API level 11

Style for setStyle(int, int): like STYLE_NO_FRAME, but also disables all input to the dialog. The user can not touch it, and its window will not receive input focus.

Constant Value: 3 (0x00000003)

public static final int STYLE_NO_TITLE

Added in API level 11

Style for setStyle(int, int): don't include a title area.

Constant Value: 1 (0x00000001)

Public Constructors

public DialogFragment ()

Added in API level 11

Public Methods

public void dismiss ()

Added in API level 11

Dismiss the fragment and its dialog. If the fragment was added to the back stack, all back stack state up to and including this entry will be popped. Otherwise, a new transaction will be committed to remove the fragment.

public void dismissAllowingStateLoss ()

Added in API level 12

Version of dismiss() that uses FragmentTransaction.commitAllowingStateLoss(). See linked documentation for further details.

public void dump (String prefix, FileDescriptor fd, PrintWriter writer, String[] args)

Added in API level 11

Print the Fragments's state into the given stream.

Parameters
prefix Text to print at the front of each line.
fd The raw file descriptor that the dump is being sent to.
writer The PrintWriter to which you should dump your state. This will be closed for you after you return.
args additional arguments to the dump request.

public Dialog getDialog ()

Added in API level 11

Returns
Dialog

public boolean getShowsDialog ()

Added in API level 11

Return the current value of setShowsDialog(boolean).

Returns
boolean

public int getTheme ()

Added in API level 11

Returns
int

public boolean isCancelable ()

Added in API level 11

Return the current value of setCancelable(boolean).

Returns
boolean

public void onActivityCreated (Bundle savedInstanceState)

Added in API level 11

Called when the fragment's activity has been created and this fragment's view hierarchy instantiated. It can be used to do final initialization once these pieces are in place, such as retrieving views or restoring state. It is also useful for fragments that use setRetainInstance(boolean) to retain their instance, as this callback tells the fragment when it is fully associated with the new activity instance. This is called after onCreateView(LayoutInflater, ViewGroup, Bundle) and before onViewStateRestored(Bundle).

Parameters
savedInstanceState If the fragment is being re-created from a previous saved state, this is the state.

public void onAttach (Activity activity)

Added in API level 11

This method is deprecated.
Use onAttach(Context) instead.

Parameters
activity

public void onCancel (DialogInterface dialog)

Added in API level 11

This method will be invoked when the dialog is canceled.

Parameters
dialog The dialog that was canceled will be passed into the method.

public void onCreate (Bundle savedInstanceState)

Added in API level 11

Called to do initial creation of a fragment. This is called after onAttach(Activity) and before onCreateView(LayoutInflater, ViewGroup, Bundle).

Note that this can be called while the fragment's activity is still in the process of being created. As such, you can not rely on things like the activity's content view hierarchy being initialized at this point. If you want to do work once the activity itself is created, see onActivityCreated(Bundle).

Parameters
savedInstanceState If the fragment is being re-created from a previous saved state, this is the state.

public Dialog onCreateDialog (Bundle savedInstanceState)

Added in API level 11

Override to build your own custom Dialog container. This is typically used to show an AlertDialog instead of a generic Dialog; when doing so, onCreateView(LayoutInflater, ViewGroup, Bundle) does not need to be implemented since the AlertDialog takes care of its own content.

This method will be called after onCreate(Bundle) and before onCreateView(LayoutInflater, ViewGroup, Bundle). The default implementation simply instantiates and returns a Dialog class.

Note: DialogFragment own the Dialog.setOnCancelListener and Dialog.setOnDismissListener callbacks. You must not set them yourself. To find out about these events, override onCancel(DialogInterface) and onDismiss(DialogInterface).

Parameters
savedInstanceState The last saved instance state of the Fragment, or null if this is a freshly created Fragment.
Returns
Dialog Return a new Dialog instance to be displayed by the Fragment.

public void onDestroyView ()

Added in API level 11

Remove dialog.

public void onDetach ()

Added in API level 11

Called when the fragment is no longer attached to its activity. This is called after onDestroy().

public void onDismiss (DialogInterface dialog)

Added in API level 11

This method will be invoked when the dialog is dismissed.

Parameters
dialog The dialog that was dismissed will be passed into the method.

public void onSaveInstanceState (Bundle outState)

Added in API level 11

Called to ask the fragment to save its current dynamic state, so it can later be reconstructed in a new instance of its process is restarted. If a new instance of the fragment later needs to be created, the data you place in the Bundle here will be available in the Bundle given to onCreate(Bundle), onCreateView(LayoutInflater, ViewGroup, Bundle), and onActivityCreated(Bundle).

This corresponds to Activity.onSaveInstanceState(Bundle) and most of the discussion there applies here as well. Note however: this method may be called at any time before onDestroy(). There are many situations where a fragment may be mostly torn down (such as when placed on the back stack with no UI showing), but its state will not be saved until its owning activity actually needs to save its state.

Parameters
outState Bundle in which to place your saved state.

public void onStart ()

Added in API level 11

Called when the Fragment is visible to the user. This is generally tied to Activity.onStart of the containing Activity's lifecycle.

public void onStop ()

Added in API level 11

Called when the Fragment is no longer started. This is generally tied to Activity.onStop of the containing Activity's lifecycle.

public void setCancelable (boolean cancelable)

Added in API level 11

Control whether the shown Dialog is cancelable. Use this instead of directly calling Dialog.setCancelable(boolean), because DialogFragment needs to change its behavior based on this.

Parameters
cancelable If true, the dialog is cancelable. The default is true.

public void setShowsDialog (boolean showsDialog)

Added in API level 11

Controls whether this fragment should be shown in a dialog. If not set, no Dialog will be created in onActivityCreated(Bundle), and the fragment's view hierarchy will thus not be added to it. This allows you to instead use it as a normal fragment (embedded inside of its activity).

This is normally set for you based on whether the fragment is associated with a container view ID passed to FragmentTransaction.add(int, Fragment). If the fragment was added with a container, setShowsDialog will be initialized to false; otherwise, it will be true.

Parameters
showsDialog If true, the fragment will be displayed in a Dialog. If false, no Dialog will be created and the fragment's view hierarchly left undisturbed.

public void setStyle (int style, int theme)

Added in API level 11

Call to customize the basic appearance and behavior of the fragment's dialog. This can be used for some common dialog behaviors, taking care of selecting flags, theme, and other options for you. The same effect can be achieve by manually setting Dialog and Window attributes yourself. Calling this after the fragment's Dialog is created will have no effect.

Parameters
style Selects a standard style: may be STYLE_NORMAL, STYLE_NO_TITLE, STYLE_NO_FRAME, or STYLE_NO_INPUT.
theme Optional custom theme. If 0, an appropriate theme (based on the style) will be selected for you.

public int show (FragmentTransaction transaction, String tag)

Added in API level 11

Display the dialog, adding the fragment using an existing transaction and then committing the transaction.

Parameters
transaction An existing transaction in which to add the fragment.
tag The tag for this fragment, as per FragmentTransaction.add.
Returns
int Returns the identifier of the committed transaction, as per FragmentTransaction.commit().

public void show (FragmentManager manager, String tag)

Added in API level 11

Display the dialog, adding the fragment to the given FragmentManager. This is a convenience for explicitly creating a transaction, adding the fragment to it with the given tag, and committing it. This does not add the transaction to the back stack. When the fragment is dismissed, a new transaction will be executed to remove it from the activity.

Parameters
manager The FragmentManager this fragment will be added to.
tag The tag for this fragment, as per FragmentTransaction.add.