android怎样写一个自己定义的dialog能够在Title的位置弹出来

先上效果图:

Title的Layout为:

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

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="@dimen/title_height"

    android:background="@drawable/bg_top_title"

   >

<TextView

    android:layout_width="wrap_content"

    android:layout_height="wrap_content"

    android:text="Title"

    android:textSize="20sp"

    android:layout_centerInParent="true"/>

    <ImageView

        android:layout_width="@dimen/header_btn_width"

        android:layout_height="wrap_content"

        android:layout_marginTop="14dp"

        android:layout_alignParentTop="true"

        android:paddingLeft="4dp"

        android:id="@+id/right_button"

        android:src="@drawable/arrow_dropdown_pressed"

        android:layout_alignParentRight="true"

        />

</RelativeLayout>

弹出的dialog的Layout为

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

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:id="@+id/dropdownBckgrnd"

    android:background="@drawable/bg_pop_up_dimmer"

    >

    <ImageView

        android:layout_width="@dimen/header_btn_width"

        android:layout_height="wrap_content"

        android:layout_marginTop="14dp"

        android:layout_alignParentTop="true"

        android:paddingLeft="4dp"

        android:id="@+id/right_button"

        android:src="@drawable/arrow_dropdown_pressed"

        android:layout_alignParentRight="true"

        />

    <LinearLayout

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:layout_gravity="center"

        android:layout_marginLeft="12dp"

        android:layout_marginRight="12dp"

        android:layout_marginTop="35dp"

        android:orientation="vertical"

        android:focusable="true"

        android:focusableInTouchMode="true"

        android:background="@drawable/topmenu_popup_down">

        <Button

            android:layout_width="fill_parent"

            android:layout_height="45dp"

            android:background="@drawable/main_menu_button_background"

            android:layout_margin="@dimen/button_margin_top"

            android:text="aaa"

            />

        <Button

            android:layout_width="fill_parent"

            android:layout_height="45dp"

            android:background="@drawable/main_menu_button_background"

            android:layout_margin="@dimen/button_margin_top"

            android:text="bbb"

            />

        <Button

            android:layout_width="fill_parent"

            android:layout_height="45dp"

            android:background="@drawable/main_menu_button_background"

            android:layout_margin="@dimen/button_margin_top"

            android:text="ccc"

            />

    </LinearLayout>

</RelativeLayout>

我们使用

 <span style="white-space:pre">	</span>mDialog = new Dialog(context,R.style.customDialog);

        mDialog.setContentView(R.layout.dialog_layout);

<style name="customDialog" parent="@android:style/Theme.Dialog">

        <item name="android:windowNoTitle">true</item> //设置title

        <item name="android:windowBackground">@android:color/transparent</item>  //dialog应该是透明背景

        <item name="android:windowIsFloating">false</item>  //dialog不是悬浮的

        <item name="android:layoutAnimation">@null</item>  //dialog弹出时没有动画

    </style>

然后我们来设置Dialog的其它属性

        mDialog = new Dialog(context,R.style.customDialog);

        mDialog.setContentView(R.layout.dialog_layout);

        mDialog.setCanceledOnTouchOutside(true);

        WindowManager.LayoutParams params = mDialog.getWindow().getAttributes();

        params.gravity = Gravity.TOP;//这个设置使这个dialog从上方弹出来

        params.windowAnimations = 1;

        WindowManager manager = (WindowManager)context.getSystemService(Context.WINDOW_SERVICE);

        Display display = manager.getDefaultDisplay();

        windowHeight	= display.getHeight();

        windowWidth	= display.getWidth();

        params.width = windowWidth;

        params.height = windowHeight;

        mDialog.findViewById(R.id.right_button).setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                mDialog.dismiss();

            }

        });

        mDialog.findViewById(R.id.dropdownBckgrnd).setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                mDialog.dismiss();

            }

        });