topics/ui/dialogs.jd

page.title=Hp thoi
page.tags=alertdialog,dialogfragment

@jd:body


<div id="qv-wrapper">
  <div id="qv">
    <h2>Trong ti liu ny</h2>
<ol>
  <li><a href="#DialogFragment">To mt Phn on Hp thoi</a></li>
  <li><a href="#AlertDialog">Xy dng mt Hp thoi Cnh bo</a>
    <ol>
      <li><a href="#AddingButtons">Thm nt</a></li>
      <li><a href="#AddingAList">Thm mt danh sch</a></li>
      <li><a href="#CustomLayout">To mt B tr Ty chnh</a></li>
    </ol>
  </li>
  <li><a href="#PassingEvents">Chuyn S kin li My ch ca Hp thoi</a></li>
  <li><a href="#ShowingADialog">Hin th mt Hp thoi</a></li>
  <li><a href="#FullscreenDialog">Hin th mt Hp thoi Ton mn hnh hoc dng mt Phn on Nhng</a>
    <ol>
      <li><a href="#ActivityAsDialog">Hin th mt hot ng di dng mt hp thoi trn mn hnh ln</a></li>
    </ol>
  </li>
  <li><a href="#DismissingADialog">B mt Hp thoi</a></li>
</ol>

    <h2>Lp kha</h2>
    <ol>
      <li>{@link android.app.DialogFragment}</li>
      <li>{@link android.app.AlertDialog}</li>
    </ol>

    <h2>Xem thm</h2>
    <ol>
      <li><a href="{@docRoot}design/building-blocks/dialogs.html">Hng dn thit k hp thoi</a></li>
      <li><a href="{@docRoot}guide/topics/ui/controls/pickers.html">B chn</a> (Hp thoi Ngy/Gi)</li>
    </ol>
  </div>
</div>

<p>Hp thoi l mt ca s nh c chc nng nhc ngi dng
a ra mt quyt nh hoc nhp thng tin b sung. Hp thoi khng lp kn mn hnh v
thng c s dng cho cc s kin m thi yu cu ngi dng phi thc hin mt hnh ng trc khi c th i tip.</p>

<div class="note design">
<p><strong>Thit k Hp thoi</strong></p>
  <p> bit thng tin v cch thit k hp thoi ca bn, bao gm cc  xut
  v ngn ng, hy c hng dn thit k <a href="{@docRoot}design/building-blocks/dialogs.html">Hp thoi</a>.</p>
</div>

<img src="{@docRoot}images/ui/dialogs.png" />

<p>Lp {@link android.app.Dialog} l lp c s cho hp thoi, nhng bn
nn trnh khi to {@link android.app.Dialog} mt cch trc tip.
Thay vo , hy s dng mt trong cc lp con sau:</p>
<dl>
  <dt>{@link android.app.AlertDialog}</dt>
  <dd>Hp thoi c th hin th mt tiu , ti a ba nt, mt danh sch
    cc mc c th chn, hoc mt b tr ty chnh.</dd>
  <dt>{@link android.app.DatePickerDialog} hoc {@link android.app.TimePickerDialog}</dt>
  <dd>Hp thoi vi mt UI c xc nh trc, cho php ngi dng chn ngy hoc gi.</dd>
</dl>

<div class="sidebox">
<h2>Trnh ProgressDialog</h2>
<p>Android c mt lp hp thoi khc gi l
{@link android.app.ProgressDialog}, n hin th mt hp thoi vi mt thanh tin . Tuy nhin, nu bn
cn ch bo tin  ti hoc cha xc nh, thay vo , bn nn tun theo hng dn
thit k dnh cho <a href="{@docRoot}design/building-blocks/progress.html">Tin  &amp;
Hot ng</a> v s dng mt {@link android.widget.ProgressBar} trong b tr ca mnh.</p>
</div>

<p>Nhng lp ny nh ngha kiu v cu trc cho hp thoi ca bn, nhng bn nn
s dng mt {@link android.support.v4.app.DialogFragment} lm b cha cho hp thoi ca mnh.
Lp {@link android.support.v4.app.DialogFragment} s cung cp tt c iu khin m
bn cn  to hp thoi ca mnh v qun l din mo ca hp thoi, thay v gi ra cc phng php
trn i tng {@link android.app.Dialog}.</p>

<p>Vic s dng {@link android.support.v4.app.DialogFragment}  qun l hp thoi
s m bo rng n x l ng cc s kin vng i
chng hn nh khi ngi dng nhn nt <em>Quay li</em> hoc xoay mn hnh. Lp {@link
android.support.v4.app.DialogFragment} cng cho php bn s dng li UI ca hp thoi nh mt
thnh phn c th nhng trong mt UI rng hn, ging nh mt {@link
android.support.v4.app.Fragment} truyn thng (chng hn nh khi bn mun UI hp thoi xut hin khc i
trn cc mn hnh ln v nh).</p>

<p>Cc phn sau trong hng dn ny m t cch s dng {@link
android.support.v4.app.DialogFragment} kt hp vi mt i tng {@link android.app.AlertDialog}
. Nu mun to mt b chn ngy hoc gi, thay vo , bn nn c hng dn
<a href="{@docRoot}guide/topics/ui/controls/pickers.html">B chn</a>.</p>

<p class="note"><strong>Lu :</strong>
V lp {@link android.app.DialogFragment} ban u c b sung cng vi
Android 3.0 (API mc 11), ti liu ny m t cch s dng lp {@link
android.support.v4.app.DialogFragment} c cung cp km <a href="{@docRoot}tools/support-library/index.html">Th vin H tr</a>. Bng cch thm th vin ny
vo ng dng ca mnh, bn c th s dng {@link android.support.v4.app.DialogFragment} v nhiu loi
API khc trn cc thit b chy Android 1.6 hoc cao hn. Nu phin bn ti thiu m ng dng ca bn h tr
l API mc 11 hoc cao hn, khi  bn c th s dng phin bn khun kh ca {@link
android.app.DialogFragment}, nhng hy ch  rng cc lin kt trong ti liu ny dnh cho cc API
th vin h  tr. Khi s dng th vin h tr,
hy nh rng bn nhp lp <code>android.support.v4.app.DialogFragment</code>
ch <em>khng phi</em> <code>android.app.DialogFragment</code>.</p>


<h2 id="DialogFragment">To mt Phn on Hp thoi</h2>

<p>Bn c th hon thnh nhiu loi thit k hp thoi&mdash;bao gm
b tr ty chnh v nhng b tr c m t trong hng dn thit k <a href="{@docRoot}design/building-blocks/dialogs.html">Hp thoi</a>
&mdash;bng cch m rng
{@link android.support.v4.app.DialogFragment} v to mt {@link android.app.AlertDialog}
trong phng php gi li {@link android.support.v4.app.DialogFragment#onCreateDialog
onCreateDialog()}.</p>

<p>V d, sau y l mt {@link android.app.AlertDialog} c bn c qun l bn trong
mt {@link android.support.v4.app.DialogFragment}:</p>

<pre>
public class FireMissilesDialogFragment extends DialogFragment {
    &#64;Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the Builder class for convenient dialog construction
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setMessage(R.string.dialog_fire_missiles)
               .setPositiveButton(R.string.fire, new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       // FIRE ZE MISSILES!
                   }
               })
               .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       // User cancelled the dialog
                   }
               });
        // Create the AlertDialog object and return it
        return builder.create();
    }
}
</pre>

<div class="figure" style="width:290px;margin:0 0 0 20px">
<img src="{@docRoot}images/ui/dialog_buttons.png" alt="" />
<p class="img-caption"><strong>Hnh 1.</strong>
Hp thoi vi mt thng bo v hai nt hnh ng.</p>
</div>

<p>Lc ny, khi bn to mt thc th thuc lp ny v gi {@link
android.support.v4.app.DialogFragment#show show()} trn i tng , hp thoi s xut hin
nh minh ha trong hnh 1.</p>

<p>Phn tip theo m t thm v vic s dng cc API {@link android.app.AlertDialog.Builder}
 to hp thoi.</p>

<p>Ty vo  phc tp ca hp thoi ca bn, bn c th trin khai nhiu loi phng php gi li khc
trong {@link android.support.v4.app.DialogFragment}, bao gm tt c
<a href="{@docRoot}guide/components/fragments.html#Lifecycle">phng php vng i phn on</a> c bn.


<h2 id="AlertDialog">Xy dng mt Hp thoi Cnh bo</h2>


<p>Lp {@link android.app.AlertDialog} cho php bn xy dng nhiu loi thit k hp thoi v
thng l lp hp thoi duy nht m bn s cn.
Nh c minh ha trong hnh 2, c ba vng trn mt hp thoi cnh bo:</p>

<div class="figure" style="width:311px;margin-top:0">
<img src="{@docRoot}images/ui/dialogs_regions.png" alt="" style="margin-bottom:0" />
<p class="img-caption"><strong>Hnh 2.</strong> B tr ca mt hp thoi.</p>
</div>

<ol>
<li><b>Tiu </b>
  <p>Tiu  khng bt buc v ch nn c s dng khi vng ni dung
  b chim bi mt thng bo chi tit, mt danh sch, hay mt b tr ty chnh. Nu bn cn nu
  mt thng bo hoc cu hi n gin (chng hn nh hp thoi trong hnh 1), bn khng cn tiu .</li>
<li><b>Vng ni dung</b>
  <p>Vng ny c th hin th mt thng bo, danh sch, hay b tr ty chnh khc.</p></li>
<li><b>Nt hnh ng</b>
  <p>S khng c qu ba nt hnh ng trong mt hp thoi.</p></li>
</ol>

<p>Lp {@link android.app.AlertDialog.Builder}
cung cp cc API cho php bn to mt {@link android.app.AlertDialog}
vi nhng kiu ni dung ny, bao gm mt b tr ty chnh.</p>

<p> xy dng mt {@link android.app.AlertDialog}:</p>

<pre>
<b>// 1. Instantiate an {@link android.app.AlertDialog.Builder} with its constructor</b>
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

<b>// 2. Chain together various setter methods to set the dialog characteristics</b>
builder.setMessage(R.string.dialog_message)
       .setTitle(R.string.dialog_title);

<b>// 3. Get the {@link android.app.AlertDialog} from {@link android.app.AlertDialog.Builder#create()}</b>
AlertDialog dialog = builder.create();
</pre>

<p>Cc ch  sau cho bit cch nh ngha cc thuc tnh hp thoi khc nhau bng cch
s dng lp {@link android.app.AlertDialog.Builder}.</p>


<h3 id="AddingButtons">Thm nt</h3>

<p> thm cc nt hnh ng nh trong hnh 2,
hy gi cc phng php {@link android.app.AlertDialog.Builder#setPositiveButton setPositiveButton()} v
{@link android.app.AlertDialog.Builder#setNegativeButton setNegativeButton()}:</p>

<pre style="clear:right">
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
// Add the buttons
builder.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int id) {
               // User clicked OK button
           }
       });
builder.setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int id) {
               // User cancelled the dialog
           }
       });
// Set other dialog properties
...

// Create the AlertDialog
AlertDialog dialog = builder.create();
</pre>

<p>Cc phng php <code>set...Button()</code> yu cu mt tiu  cho nt (c cung cp
bi mt <a href="{@docRoot}guide/topics/resources/string-resource.html">ti nguyn xu</a>) v mt
{@link android.content.DialogInterface.OnClickListener} c chc nng nh ngha hnh ng s tin hnh
khi ngi dng nhn nt.</p>

<p>C ba nt hnh ng khc nhau m bn c th thm:</p>
<dl>
  <dt>Tch cc</dt>
  <dd>Bn nn s dng nt ny  chp nhn v tip tc vi hnh ng (hnh ng "OK").</dd>
  <dt>Tiu cc</dt>
  <dd>Bn nn s dng nt ny  hy b hnh ng.</dd>
  <dt>Trung lp</dt>
  <dd>Bn nn s dng nt ny khi ngi dng c th khng mun tip tc vi hnh ng,
  nhng khng hn mun hy b. N nm  gia nt
  tch cc v tiu cc. V d, hnh ng c th l "Nhc ti sau."</dd>
</dl>

<p>Bn ch c th thm mt nt mi loi vo mt {@link
android.app.AlertDialog}. Ngha l, bn khng th c nhiu hn mt nt "tch cc".</p>


<div class="figure" style="width:290px;margin:0 0 0 40px">
<img src="{@docRoot}images/ui/dialog_list.png" alt="" />
<p class="img-caption"><strong>Hnh 3.</strong>
Hp thoi c tiu  v danh sch.</p>
</div>

<h3 id="AddingAList">Thm mt danh sch</h3>

<p>C ba loi danh sch c sn vi cc API {@link android.app.AlertDialog}:</p>
<ul>
<li>Danh sch mt la chn truyn thng</li>
<li>Danh sch mt la chn c nh (nt chn mt)</li>
<li>Danh sch nhiu la chn c nh (hp kim)</li>
</ul>

<p> to danh sch mt la chn nh danh sch trong hnh 3,
hy s dng phng php {@link android.app.AlertDialog.Builder#setItems setItems()}:</p>

<pre style="clear:right">
&#64;Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setTitle(R.string.pick_color)
           .setItems(R.array.colors_array, new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int which) {
               // The 'which' argument contains the index position
               // of the selected item
           }
    });
    return builder.create();
}
</pre>

<p>V danh sch xut hin trong vng ni dung ca hp thoi,
hp thoi khng th hin th c thng bo v danh sch v bn nn t mt tiu  cho hp thoi
bng {@link android.app.AlertDialog.Builder#setTitle setTitle()}.
 ch nh cc mc cho danh sch, hy gi {@link
android.app.AlertDialog.Builder#setItems setItems()}, chuyn mt mng.
Hoc, bn c th ch nh mt danh sch bng cch s dng {@link
android.app.AlertDialog.Builder#setAdapter setAdapter()}. iu ny cho php bn h tr danh sch
bng d liu ng (chng hn nh t mt c s d liu) bng cch s dng {@link android.widget.ListAdapter}.</p>

<p>Nu bn chn h tr danh sch ca mnh bng mt {@link android.widget.ListAdapter},
hy lun s dng {@link android.support.v4.content.Loader} sao cho ni dung ti
khng ng b. iu ny c m t thm trong hng dn
<a href="{@docRoot}guide/topics/ui/declaring-layout.html#AdapterViews">Xy dng B tr
bng mt Trnh iu hp</a> v <a href="{@docRoot}guide/components/loaders.html">Trnh ti</a>
.</p>

<p class="note"><strong>Lu :</strong> Theo mc nh, chm vo mt mc danh sch s b hp thoi,
tr khi bn ang s dng mt trong cc danh sch la chn c nh sau.</p>

<div class="figure" style="width:290px;margin:-30px 0 0 40px">
<img src="{@docRoot}images/ui/dialog_checkboxes.png" />
<p class="img-caption"><strong>Hnh 4.</strong>
Danh sch nhiu mc la chn.</p>
</div>


<h4 id="Checkboxes">Thm mt danh sch nhiu la chn hoc mt la chn c nh</h4>

<p> thm mt danh sch nhiu la chn (hp kim) hoc
mt la chn (nt chn mt), hy s dng cc phng php
{@link android.app.AlertDialog.Builder#setMultiChoiceItems(Cursor,String,String,
DialogInterface.OnMultiChoiceClickListener) setMultiChoiceItems()} hoc
{@link android.app.AlertDialog.Builder#setSingleChoiceItems(int,int,DialogInterface.OnClickListener)
setSingleChoiceItems()} tng ng.</p>

<p>V d, sau y l cch bn c th to mt danh sch nhiu la chn nh
danh sch c minh ha trong hnh 4 gip lu cc mc
c chn trong mt {@link java.util.ArrayList}:</p>

<pre style="clear:right">
&#64;Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    mSelectedItems = new ArrayList();  // Where we track the selected items
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    // Set the dialog title
    builder.setTitle(R.string.pick_toppings)
    // Specify the list array, the items to be selected by default (null for none),
    // and the listener through which to receive callbacks when items are selected
           .setMultiChoiceItems(R.array.toppings, null,
                      new DialogInterface.OnMultiChoiceClickListener() {
               &#64;Override
               public void onClick(DialogInterface dialog, int which,
                       boolean isChecked) {
                   if (isChecked) {
                       // If the user checked the item, add it to the selected items
                       mSelectedItems.add(which);
                   } else if (mSelectedItems.contains(which)) {
                       // Else, if the item is already in the array, remove it
                       mSelectedItems.remove(Integer.valueOf(which));
                   }
               }
           })
    // Set the action buttons
           .setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
               &#64;Override
               public void onClick(DialogInterface dialog, int id) {
                   // User clicked OK, so save the mSelectedItems results somewhere
                   // or return them to the component that opened the dialog
                   ...
               }
           })
           .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
               &#64;Override
               public void onClick(DialogInterface dialog, int id) {
                   ...
               }
           });

    return builder.create();
}
</pre>

<p>Mc d c danh sch truyn thng v danh sch c nt chn mt
u cung cp hnh ng "mt la chn", bn nn s dng {@link
android.app.AlertDialog.Builder#setSingleChoiceItems(int,int,DialogInterface.OnClickListener)
setSingleChoiceItems()} nu bn mun c nh la chn ca ngi dng.
C th, nu vic m hp thoi li sau ny bo hiu la chn hin ti ca ngi dng, khi
bn hy to mt danh sch vi cc nt chn mt.</p>


<h3 id="CustomLayout">To mt B tr Ty chnh</h3>

<div class="figure" style="width:290px;margin:-30px 0 0 40px">
<img src="{@docRoot}images/ui/dialog_custom.png" alt="" />
<p class="img-caption"><strong>Hnh 5.</strong> Mt b tr hp thoi ty chnh.</p>
</div>

<p>Nu bn mun mt b tr ty chnh trong mt hp thoi, hy to mt b tr v thm n vo mt
{@link android.app.AlertDialog} bng cch gi {@link
android.app.AlertDialog.Builder#setView setView()} trn i tng {@link
android.app.AlertDialog.Builder} ca bn.</p>

<p>Theo mc nh, b tr ty chnh s lp y ca s hp thoi, nhng bn vn c th
s dng cc phng php {@link android.app.AlertDialog.Builder}  thm nt v tiu .</p>

<p>V d, sau y l tp b tr cho hp thoi trong Hnh 5:</p>

<p style="clear:right" class="code-caption">res/layout/dialog_signin.xml</p>
<pre>
&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    &lt;ImageView
        android:src="@drawable/header_logo"
        android:layout_width="match_parent"
        android:layout_height="64dp"
        android:scaleType="center"
        android:background="#FFFFBB33"
        android:contentDescription="@string/app_name" />
    &lt;EditText
        android:id="@+id/username"
        android:inputType="textEmailAddress"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:layout_marginLeft="4dp"
        android:layout_marginRight="4dp"
        android:layout_marginBottom="4dp"
        android:hint="@string/username" />
    &lt;EditText
        android:id="@+id/password"
        android:inputType="textPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="4dp"
        android:layout_marginLeft="4dp"
        android:layout_marginRight="4dp"
        android:layout_marginBottom="16dp"
        android:fontFamily="sans-serif"
        android:hint="@string/password"/>
&lt;/LinearLayout>
</pre>

<p class="note"><strong>Mo:</strong> Theo mc nh, khi bn t mt phn t {@link android.widget.EditText}
 s dng kiu u vo {@code "textPassword"}, h phng c t thnh n cch, v th
bn nn i h phng thnh {@code "sans-serif"} sao cho c hai trng vn bn u s dng
mt kiu phng thng nht.</p>

<p> bung b tr ra trong {@link android.support.v4.app.DialogFragment} ca bn,
hy ly mt {@link android.view.LayoutInflater} vi
{@link android.app.Activity#getLayoutInflater()} v gi
{@link android.view.LayoutInflater#inflate inflate()}, trong  tham s u tin
l ID ti nguyn b tr v tham s th hai l mt dng xem m cho b tr.
Khi , bn c th gi {@link android.app.AlertDialog#setView setView()}
 t b tr vo mt hp thoi.</p>

<pre>
&#64;Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    // Get the layout inflater
    LayoutInflater inflater = getActivity().getLayoutInflater();

    // Inflate and set the layout for the dialog
    // Pass null as the parent view because its going in the dialog layout
    builder.setView(inflater.inflate(R.layout.dialog_signin, null))
    // Add action buttons
           .setPositiveButton(R.string.signin, new DialogInterface.OnClickListener() {
               &#64;Override
               public void onClick(DialogInterface dialog, int id) {
                   // sign in the user ...
               }
           })
           .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
               public void onClick(DialogInterface dialog, int id) {
                   LoginDialogFragment.this.getDialog().cancel();
               }
           });
    return builder.create();
}
</pre>

<div class="note">
<p><strong>Mo:</strong> Nu bn mun mt hp thoi ty chnh,
thay vo , bn c th hin th {@link android.app.Activity} nh l mt hp thoi
thay v s dng cc API {@link android.app.Dialog}. Ch cn to mt hot ng v t ch  ca n thnh
{@link android.R.style#Theme_Holo_Dialog Theme.Holo.Dialog}
trong phn t bn k khai <a href="{@docRoot}guide/topics/manifest/activity-element.html">{@code
&lt;activity&gt;}</a>:</p>

<pre>
&lt;activity android:theme="&#64;android:style/Theme.Holo.Dialog" >
</pre>
<p>Vy l xong. Lc ny, hot ng s hin th mt ca s hp thoi thay v ton mn hnh.</p>
</div>


<h2 id="PassingEvents">Chuyn S kin li My ch ca Hp thoi</h2>

<p>Khi ngi dng chm vo mt trong cc nt hnh ng ca hp thoi hoc chn mt mc t danh sch ca hp thoi,
{@link android.support.v4.app.DialogFragment} ca bn c th t thc hin hnh ng
cn thit, nhng thng th bn s mun chuyn s kin ti hot ng hoc phn on
 m hp thoi.  lm iu ny, hy nh ngha mt giao din bng mt phng php cho mi loi s kin nhp.
Sau , trin khai giao din  trong thnh phn ch m s
nhn s kin hnh ng t hp thoi.</p>

<p>V d, sau y l mt {@link android.support.v4.app.DialogFragment} c chc nng nh ngha mt
giao din m thng qua , n s chuyn cc s kin li cho hot ng ch:</p>

<pre>
public class NoticeDialogFragment extends DialogFragment {

    /* The activity that creates an instance of this dialog fragment must
     * implement this interface in order to receive event callbacks.
     * Each method passes the DialogFragment in case the host needs to query it. */
    public interface NoticeDialogListener {
        public void onDialogPositiveClick(DialogFragment dialog);
        public void onDialogNegativeClick(DialogFragment dialog);
    }

    // Use this instance of the interface to deliver action events
    NoticeDialogListener mListener;

    // Override the Fragment.onAttach() method to instantiate the NoticeDialogListener
    &#64;Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        // Verify that the host activity implements the callback interface
        try {
            // Instantiate the NoticeDialogListener so we can send events to the host
            mListener = (NoticeDialogListener) activity;
        } catch (ClassCastException e) {
            // The activity doesn't implement the interface, throw exception
            throw new ClassCastException(activity.toString()
                    + " must implement NoticeDialogListener");
        }
    }
    ...
}
</pre>

<p>Hot ng lu gi hp thoi s to mt thc th ca hp thoi
bng hm dng ca phn on hp thoi v nhn s kin
ca hp thoi thng qua trin khai giao din {@code NoticeDialogListener}:</p>

<pre>
public class MainActivity extends FragmentActivity
                          implements NoticeDialogFragment.NoticeDialogListener{
    ...

    public void showNoticeDialog() {
        // Create an instance of the dialog fragment and show it
        DialogFragment dialog = new NoticeDialogFragment();
        dialog.show(getSupportFragmentManager(), "NoticeDialogFragment");
    }

    // The dialog fragment receives a reference to this Activity through the
    // Fragment.onAttach() callback, which it uses to call the following methods
    // defined by the NoticeDialogFragment.NoticeDialogListener interface
    &#64;Override
    public void onDialogPositiveClick(DialogFragment dialog) {
        // User touched the dialog's positive button
        ...
    }

    &#64;Override
    public void onDialogNegativeClick(DialogFragment dialog) {
        // User touched the dialog's negative button
        ...
    }
}
</pre>

<p>V hot ng ch s trin khai {@code NoticeDialogListener}&mdash;, c
thc thi bi phng php gi li {@link android.support.v4.app.Fragment#onAttach onAttach()}
minh ha bn trn,&mdash;phn on hp thoi c th s dng cc phng php gi li
giao din  chuyn cc s kin nhp cho hot ng:</p>

<pre>
public class NoticeDialogFragment extends DialogFragment {
    ...

    &#64;Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Build the dialog and set up the button click handlers
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setMessage(R.string.dialog_fire_missiles)
               .setPositiveButton(R.string.fire, new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       // Send the positive button event back to the host activity
                       mListener.onDialogPositiveClick(NoticeDialogFragment.this);
                   }
               })
               .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int id) {
                       // Send the negative button event back to the host activity
                       mListener.onDialogNegativeClick(NoticeDialogFragment.this);
                   }
               });
        return builder.create();
    }
}
</pre>


<h2 id="ShowingADialog">Hin th mt Hp thoi</h2>

<p>Khi bn mun hin th hp thoi ca mnh, hy to mt thc th {@link
android.support.v4.app.DialogFragment} ca bn v gi {@link android.support.v4.app.DialogFragment#show
show()}, chuyn {@link android.support.v4.app.FragmentManager} v mt tn tag
cho phn on hp thoi.</p>

<p>Bn c th nhn c {@link android.support.v4.app.FragmentManager} bng cch gi
{@link android.support.v4.app.FragmentActivity#getSupportFragmentManager()} t
{@link android.support.v4.app.FragmentActivity} hoc {@link
android.support.v4.app.Fragment#getFragmentManager()} t mt {@link
android.support.v4.app.Fragment}. V d:</p>

<pre>
public void confirmFireMissiles() {
    DialogFragment newFragment = new FireMissilesDialogFragment();
    newFragment.show(getSupportFragmentManager(), "missiles");
}
</pre>

<p>Tham i th hai, {@code "missiles"}, l mt tn tag duy nht m h thng s dng  lu
v khi phc trng thi ca phn on khi cn thit. Tag cng cho php bn nhn mt iu khin (handle) cho
phn on bng cch gi {@link android.support.v4.app.FragmentManager#findFragmentByTag
findFragmentByTag()}.</p>


<h2 id="FullscreenDialog">Hin th mt Hp thoi Ton mn hnh hoc dng mt Phn on Nhng</h2>

<p>Bn c th c mt thit k UI m trong  bn mun mt phn UI xut hin nh mt hp thoi trong mt s
tnh hung, nhng  di dng ton mn hnh hoc phn on nhng trong trng hp khc (c th ph thuc
vo thit b l mn hnh ln hay nh). Lp {@link android.support.v4.app.DialogFragment}
cung cp cho bn s linh hot ny v n vn c th ng vai tr nh mt {@link
android.support.v4.app.Fragment} nhng c.</p>

<p>Tuy nhin, bn khng th s dng {@link android.app.AlertDialog.Builder AlertDialog.Builder}
hay cc i tng {@link android.app.Dialog} khc  xy dng hp thoi trong trng hp ny. Nu
bn mun {@link android.support.v4.app.DialogFragment} c th
nhng c, bn phi nh ngha UI ca hp thoi trong mt b tr, ri ti b tr  trong lnh gi li
{@link android.support.v4.app.DialogFragment#onCreateView
onCreateView()}.</p>

<p>Sau y l mt v d {@link android.support.v4.app.DialogFragment} c th xut hin nh mt
hp thoi hoc phn on nhng c (s dng mt b tr c tn gi <code>purchase_items.xml</code>):</p>

<pre>
public class CustomDialogFragment extends DialogFragment {
    /** The system calls this to get the DialogFragment's layout, regardless
        of whether it's being displayed as a dialog or an embedded fragment. */
    &#64;Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // Inflate the layout to use as dialog or embedded fragment
        return inflater.inflate(R.layout.purchase_items, container, false);
    }

    /** The system calls this only when creating the layout in a dialog. */
    &#64;Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // The only reason you might override this method when using onCreateView() is
        // to modify any dialog characteristics. For example, the dialog includes a
        // title by default, but your custom layout might not need it. So here you can
        // remove the dialog title, but you must call the superclass to get the Dialog.
        Dialog dialog = super.onCreateDialog(savedInstanceState);
        dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
        return dialog;
    }
}
</pre>

<p>V sau y l mt s m quyt nh xem hin th phn on nh mt hp thoi
hay UI ton mn hnh, da vo kch c mn hnh:</p>

<pre>
public void showDialog() {
    FragmentManager fragmentManager = getSupportFragmentManager();
    CustomDialogFragment newFragment = new CustomDialogFragment();

    if (mIsLargeLayout) {
        // The device is using a large layout, so show the fragment as a dialog
        newFragment.show(fragmentManager, "dialog");
    } else {
        // The device is smaller, so show the fragment fullscreen
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        // For a little polish, specify a transition animation
        transaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
        // To make it fullscreen, use the 'content' root view as the container
        // for the fragment, which is always the root view for the activity
        transaction.add(android.R.id.content, newFragment)
                   .addToBackStack(null).commit();
    }
}
</pre>

<p> bit thm thng tin v vic thc hin cc giao tc phn on, hy xem hng dn
<a href="{@docRoot}guide/components/fragments.html">Phn on</a>.</p>

<p>Trong v d ny, boolean <code>mIsLargeLayout</code> ch nh liu thit b hin ti
c nn s dng thit k b tr ln ca ng dng (v v th, n hin th phn on ny nh mt hp thoi thay v
ton mn hnh) hay khng. Cch tt nht  t loi boolean ny  l khai bo mt
<a href="{@docRoot}guide/topics/resources/more-resources.html#Bool">gi tr ti nguyn bool</a>
bng mt gi tr <a href="{@docRoot}guide/topics/resources/providing-resources.html#AlternativeResources">ti nguyn thay th</a> cho cc kch c mn hnh khc nhau. V d, sau y l hai
phin bn ca ti nguyn bool cho cc kch c mn hnh khc nhau:</p>

<p class="code-caption">res/values/bools.xml</p>
<pre>
&lt;!-- Default boolean values -->
&lt;resources>
    &lt;bool name="large_layout">false&lt;/bool>
&lt;/resources>
</pre>

<p class="code-caption">res/values-large/bools.xml</p>
<pre>
&lt;!-- Large screen boolean values -->
&lt;resources>
    &lt;bool name="large_layout">true&lt;/bool>
&lt;/resources>
</pre>

<p>Khi , bn c th khi to gi tr {@code mIsLargeLayout} trong phng php
{@link android.app.Activity#onCreate onCreate()} ca hot ng:</p>

<pre>
boolean mIsLargeLayout;

&#64;Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mIsLargeLayout = getResources().getBoolean(R.bool.large_layout);
}
</pre>


<h3 id="ActivityAsDialog">Hin th mt hot ng di dng mt hp thoi trn mn hnh ln</h3>

<p>Thay v hin th mt hp thoi thnh UI ton mn hnh trn cc mn hnh nh, bn c th t c
kt qu tng t bng cch hin th mt {@link android.app.Activity} thnh mt hp thoi trn
mn hnh ln. Phng php m bn chn ph thuc vo thit k ng dng ca bn, nhng
vic hin th mt hot ng thnh mt hp thoi thng c ch khi ng dng ca bn  c thit k cho mn hnh
nh v bn mun ci thin tri nghim trn my tnh bng bng cch hin th mt hot ng c vng i ngn
thnh mt hp thoi.</p>

<p> hin th mt hot ng thnh mt hp thoi ch khi trn mn hnh ln,
hy p dng ch  {@link android.R.style#Theme_Holo_DialogWhenLarge Theme.Holo.DialogWhenLarge}
cho phn t bn k khai <a href="{@docRoot}guide/topics/manifest/activity-element.html">{@code
&lt;activity&gt;}</a>:</p>

<pre>
&lt;activity android:theme="&#64;android:style/Theme.Holo.DialogWhenLarge" >
</pre>

<p> bit thm thng tin v vic to kiu cho cc hot ng ca bn bng ch , hy xem hng dn <a href="{@docRoot}guide/topics/ui/themes.html">Kiu v Ch </a>.</p>


<h2 id="DismissingADialog">B mt Hp thoi</h2>

<p>Khi ngi dng chm vo bt k nt hnh ng no c to bng
{@link android.app.AlertDialog.Builder}, h thng s b hp thoi cho bn.</p>

<p>H thng cng b hp thoi khi ngi dng chm vo mt mc trong mt danh sch hp thoi, tr
khi danh sch s dng nt chn mt hoc hp kim. Nu khng, bn c th b th cng hp thoi ca mnh
bng cch gi {@link android.support.v4.app.DialogFragment#dismiss()} trn {@link
android.support.v4.app.DialogFragment} ca bn.</p>

<p>Trong trng hp bn cn thc hin cc
hnh ng nht nh khi hp thoi bin mt, bn c th trin khai phng php {@link
android.support.v4.app.DialogFragment#onDismiss onDismiss()} trong {@link
android.support.v4.app.DialogFragment} ca mnh.</p>

<p>Bn cng c th <em>hy b</em> mt hp thoi. y l mt s kin c bit ch bo ngi dng
ch  ri khi hp thoi m khng hon thnh tc v. iu ny xy ra nu ngi dng nhn nt
<em>Quay li</em>, chm vo mn hnh ngoi vng hp thoi,
hoc nu bn cng khai gi {@link android.app.Dialog#cancel()} trn {@link
android.app.Dialog} (chng hn nh khi hi p li mt nt "Hy b" trong hp thoi).</p>

<p>Nh nu trong v d bn trn, bn c th hi p li s kin hy b ny bng cch trin khai
{@link android.support.v4.app.DialogFragment#onCancel onCancel()} trong lp {@link
android.support.v4.app.DialogFragment} ca mnh.</p>

<p class="note"><strong>Lu :</strong> H thng s gi
{@link android.support.v4.app.DialogFragment#onDismiss onDismiss()} trn mi s kin m
gi ra lnh gi li {@link android.support.v4.app.DialogFragment#onCancel onCancel()}. Tuy nhin,
nu bn gi {@link android.app.Dialog#dismiss Dialog.dismiss()} hoc {@link
android.support.v4.app.DialogFragment#dismiss DialogFragment.dismiss()},
h thng s gi {@link android.support.v4.app.DialogFragment#onDismiss onDismiss()} <em>ch
khng phi</em> {@link android.support.v4.app.DialogFragment#onCancel onCancel()}. V th, nhn chung bn nn
gi {@link android.support.v4.app.DialogFragment#dismiss dismiss()} khi ngi dng nhn nt
<em>tch cc</em> trong hp thoi ca bn  xa hp thoi khi dng xem.</p>