DialogFragment

从Android 3.0 (API level 11)开始引入，如果想在低于该版本的系统上使用，需用android.support.v4.app.DialogFragment来代替android.app.DialogFragment

0.Dialog的布局结构:

1:Title部分，该部分不是必须的（可以显示，也可以隐藏）

2:内容区域，该部分用来显示你定义的message,list，或者你的自定义布局

3:按钮区域，显示确定取消按钮的（其实中间还有个按钮，不过一般不用）。

1.建立一个普通的Dialog

       @NonNull

       @Override

       public Dialog onCreateDialog(Bundle savedInstanceState) {

           AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

           builder.setTitle("这是个title");

           builder.setMessage("如你所见，这是个message");

           builder.setPositiveButton("确定",null);

           builder.setNegativeButton("取消",null);

          return builder.create();

       }

2.显示List样式的Dialog

     @NonNull

    @Override

    public Dialog onCreateDialog(Bundle savedInstanceState) {

        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

        builder.setTitle("这是个title");

        builder.setItems(new String[]{"blue","yellow","green"},null);

        return builder.create();

    }

注意：dialog无法同时显示message跟list

你也可以使用builder的setAdapter方法来使用ListAdapter动态显示list

3.显示多选（checkbox）或单选(radiobutton)list的Dialog

可分别调用AlertDialog.Builder的 setMultiChoiceItems()方法，或setSingleChoiceItems()方法

@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() {

               @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() {

               @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() {

               @Override

               public void onClick(DialogInterface dialog, int id) {

                   ...

               }

           });

    return builder.create();

}

4.使用自定义布局

 使用AlertDialog.Buidler的setView()方法来设置自定义布局。默认情况下，自定义布局会填满Dialog的窗口，当然，也可以继续设置title和button

 先上效果图：

  layout：

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

              android:orientation="vertical"

              android:layout_width="wrap_content"

              android:layout_height="wrap_content">

    <TextView

        android:layout_width="match_parent"

        android:layout_height="64dp"

        android:gravity="center"

        android:textStyle="bold"

        android:textSize="26dp"

        android:background="#FFFFBB33"

        android:text="Android App"

     />

    <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="username" />

    <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="password"/>

</LinearLayout>

    @NonNull

    @Override

    public Dialog onCreateDialog(Bundle savedInstanceState) {

        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());

        builder.setView(R.layout.login_dialog);

        builder.setNegativeButton("cancle",null);

        builder.setPositiveButton("Sign in",null);

        return builder.create();

    }

5.显示dialog

public void confirmFireMissiles() {

    DialogFragment newFragment = new FireMissilesDialogFragment();

    newFragment.show(getSupportFragmentManager(), "missiles");

}