Android 提供了 AlertDialog 类可通过其内部类 Builder 轻松创建对话框窗口，但是没法对这个对话框窗口进行定制，为了修改 AlertDialog 窗口显示的外观，解决的办法就是创建一个指定的 AlertDialog 和 AlertDialog.Builder 类。
定义外观
我们希望将上面默认的对话框外观修改为如下图所示的新对话框风格：
该对话框将支持下面特性：
可从资源或者字符串直接指定对话框标题
可从资源、字符串和自定义布局来设置对话框内容
可设置按钮和相应的事件处理
编写布局、样式和主题
该对话框使用一个定制的布局来输出内容，布局定义的id将用于访问标题 TextView，下面是定义文件：
01 <?xml version="1.0" encoding="utf-8"?>
02 <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
03android:orientation="vertical"
04android:layout_width="fill_parent"
05android:minWidth="280dip"
06android:layout_height="wrap_content">
07
08<LinearLayout
09android:orientation="vertical"
10android:background="@drawable/header"
11android:layout_width="fill_parent"
12android:layout_height="wrap_content">
13
14<TextView
15style="@style/DialogText.Title"
16android:id="@+id/title"
17android:paddingRight="8dip"
18android:paddingLeft="8dip"
19android:background="@drawable/title"
20android:layout_width="wrap_content"
21android:layout_height="wrap_content"/>
22
23</LinearLayout>
24
25<LinearLayout
26android:id="@+id/content"
27android:orientation="vertical"
28android:background="@drawable/center"
29android:layout_width="fill_parent"
30android:layout_height="wrap_content">
31
32<TextView
33style="@style/DialogText"
34android:id="@+id/message"
35android:padding="5dip"
36android:layout_width="fill_parent"
37android:layout_height="wrap_content"/>
38
39</LinearLayout>
40
41<LinearLayout
42android:orientation="horizontal"
43android:background="@drawable/footer"
44android:layout_width="fill_parent"
45android:layout_height="wrap_content">
46
47<Button
48android:id="@+id/positiveButton"
49android:layout_marginTop="3dip"
50android:layout_width="0dip"
51android:layout_weight="1"
52android:layout_height="wrap_content"
53android:singleLine="true"/>
54
55<Button
56android:id="@+id/negativeButton"
57android:layout_marginTop="3dip"
58android:layout_width="0dip"
59android:layout_weight="1"
60android:layout_height="wrap_content"
61android:singleLine="true"/>
62
63</LinearLayout>
64
65 </LinearLayout>
根节点 LinearLayout 的宽度设置为 fill_parent 而最小的宽度是 280dip ，因此对话框的宽度将始终为屏幕宽度的 87.5%
自定义的主题用于声明对话框是浮动的，而且使用自定义的背景和标题视图：
01 <?xml version="1.0" encoding="utf-8"?>
02 <resources>
03
04<style name="Dialog" parent="android:style/Theme.Dialog">
05<item name="android:windowBackground">@null</item>
06<item name="android:windowNoTitle">true</item>
07<item name="android:windowIsFloating">true</item>
08</style>
09
10 </resources>
接下来我们需要定义对话框的标题和消息的显示：
01 <?xml version="1.0" encoding="utf-8"?>
02 <resources>
03
04<style name="DialogText">
05<item name="android:textColor">#FF000000</item>
06<item name="android:textSize">12sp</item>
07</style>
08
09<style name="DialogText.Title">
10<item name="android:textSize">16sp</item>
11<item name="android:textStyle">bold</item>
12</style>
13
14 </resources>
编写对话框和 Builder 类
最好我们要提供跟 AletDialog.Builder 类一样的方法：
001 package net.androgames.blog.sample.customdialog.dialog;
002
003 import net.androgames.blog.sample.customdialog.R;
004 import android.app.Dialog;
005 import android.content.Context;
006 import android.content.DialogInterface;
007 import android.view.LayoutInflater;
008 import android.view.View;
009 import android.view.ViewGroup.LayoutParams;
010 import android.widget.Button;
011 import android.widget.LinearLayout;
012 import android.widget.TextView;
013
014 /**
015*
016* Create custom Dialog windows for your application
017* Custom dialogs rely on custom layouts wich allow you to
018* create and use your own look & feel.
019*
020* Under GPL v3 : http://www.gnu.org/licenses/gpl-3.0.html
021*
022* <a href="http://my.oschina.net/arthor" target="_blank" rel="nofollow">@author</a> antoine vianey
023*
024*/
025 public class CustomDialog extends Dialog {
026
027public CustomDialog(Context context, int theme) {
028super(context, theme);
029}
030
031public CustomDialog(Context context) {
032super(context);
033}
034
035/**
036* Helper class for creating a custom dialog
037*/
038public static class Builder {
039
040private Context context;
041private String title;
042private String message;
043private String positiveButtonText;
044private String negativeButtonText;
045private View contentView;
046
047privateDialogInterface.OnClickListener
048positiveButtonClickListener,
049negativeButtonClickListener;
050
051public Builder(Context context) {
052this.context = context;
053}
054
055/**
056* Set the Dialog message from String
057* @param title
058* @return
059*/
060public Builder setMessage(String message) {
061this.message = message;
062return this;
063}
064
065/**
066* Set the Dialog message from resource
067* @param title
068* @return
069*/
070public Builder setMessage(int message) {
071this.message = (String) context.getText(message);
072return this;
073}
074
075/**
076* Set the Dialog title from resource
077* @param title
078* @return
079*/
080public Builder setTitle(int title) {
081this.title = (String) context.getText(title);
082return this;
083}
084
085/**
086* Set the Dialog title from String
087* @param title
088* @return
089*/
090public Builder setTitle(String title) {
091this.title = title;
092return this;
093}
094
095/**
096* Set a custom content view for the Dialog.
097* If a message is set, the contentView is not
098* added to the Dialog...
099* @param v
100* @return
101*/
102public Builder setContentView(View v) {
103this.contentView = v;
104return this;
105}
106
107/**
108* Set the positive button resource and it's listener
109* @param positiveButtonText
110* @param listener
111* @return
112*/
113public Builder setPositiveButton(int positiveButtonText,
114DialogInterface.OnClickListener listener) {
115this.positiveButtonText = (String) context
116.getText(positiveButtonText);
117this.positiveButtonClickListener = listener;
118return this;
119}
120
121/**
122* Set the positive button text and it's listener
123* @param positiveButtonText
124* @param listener
125* @return
126*/
127public Builder setPositiveButton(String positiveButtonText,
128DialogInterface.OnClickListener listener) {
129this.positiveButtonText = positiveButtonText;
130this.positiveButtonClickListener = listener;
131return this;
132}
133
134/**
135* Set the negative button resource and it's listener
136* @param negativeButtonText
137* @param listener
138* @return
139*/
140public Builder setNegativeButton(int negativeButtonText,
141DialogInterface.OnClickListener listener) {
142this.negativeButtonText = (String) context
143.getText(negativeButtonText);
144this.negativeButtonClickListener = listener;
145return this;
146}
147
148/**
149* Set the negative button text and it's listener
150* @param negativeButtonText
151* @param listener
152* @return
153*/
154public Builder setNegativeButton(String negativeButtonText,
155DialogInterface.OnClickListener listener) {
156this.negativeButtonText = negativeButtonText;
157this.negativeButtonClickListener = listener;
158return this;
159}
160
161/**
162* Create the custom dialog
163*/
164public CustomDialog create() {
165LayoutInflater inflater = (LayoutInflater) context
166.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
167// instantiate the dialog with the custom Theme
168final CustomDialog dialog = newCustomDialog(context,
169R.style.Dialog);
170View layout = inflater.inflate(R.layout.dialog, null);
171dialog.addContentView(layout, new LayoutParams(
172LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
173// set the dialog title
174((TextView) layout.findViewById(R.id.title)).setText(title);
175// set the confirm button
176if (positiveButtonText != null) {
177((Button) layout.findViewById(R.id.positiveButton))
178.setText(positiveButtonText);
179if (positiveButtonClickListener != null) {
180((Button) layout.findViewById(R.id.positiveButton))
181.setOnClickListener(newView.OnClickListener() {
182public void onClick(View v) {
183positiveButtonClickListener.onClick(
184dialog,
185DialogInterface.BUTTON_POSITIVE);
186}
187});
188}
189} else {
190// if no confirm button just set the visibility to GONE
191layout.findViewById(R.id.positiveButton).setVisibility(
192View.GONE);
193}
194// set the cancel button
195if (negativeButtonText != null) {
196((Button) layout.findViewById(R.id.negativeButton))
197.setText(negativeButtonText);
198if (negativeButtonClickListener != null) {
199((Button) layout.findViewById(R.id.negativeButton))
200.setOnClickListener(newView.OnClickListener() {
201public void onClick(View v) {
202positiveButtonClickListener.onClick(
203dialog,
204DialogInterface.BUTTON_NEGATIVE);
205}
206});
207}
208} else {
209// if no confirm button just set the visibility to GONE
210layout.findViewById(R.id.negativeButton).setVisibility(
211View.GONE);
212}
213// set the content message
214if (message != null) {
215((TextView) layout.findViewById(
216R.id.message)).setText(message);
217} else if (contentView != null) {
218// if no message set
219// add the contentView to the dialog body
220((LinearLayout) layout.findViewById(R.id.content))
221.removeAllViews();
222((LinearLayout) layout.findViewById(R.id.content))
223.addView(contentView,
224new LayoutParams(
225LayoutParams.WRAP_CONTENT,
226LayoutParams.WRAP_CONTENT));
227}
228dialog.setContentView(layout);
229return dialog;
230}
231
232}
233
234 }
使用自定义的 Builder
使用方法很简单：
01 /**
02* Build the desired Dialog
03* CUSTOM or DEFAULT
04*/
05 @Override
06 public Dialog onCreateDialog(int dialogId) {
07Dialog dialog = null;
08switch (dialogId) {
09case CUSTOM_DIALOG :
10CustomDialog.Builder customBuilder = new
11CustomDialog.Builder(CustomDialogActivity.this);
12customBuilder.setTitle("Custom title")
13.setMessage("Custom body")
14.setNegativeButton("Cancel",
15new DialogInterface.OnClickListener() {
16public void onClick(DialogInterface dialog, intwhich) {
17CustomDialogActivity.this
18.dismissDialog(CUSTOM_DIALOG);
19}
20})
21.setPositiveButton("Confirm",
22new DialogInterface.OnClickListener() {
23public void onClick(DialogInterface dialog, intwhich) {
24dialog.dismiss();
25}
26});
27dialog = customBuilder.create();
28break;
29case DEFAULT_DIALOG :
30AlertDialog.Builder alertBuilder = new
31AlertDialog.Builder(CustomDialogActivity.this);
32alertBuilder.setTitle("Default title")
33.setMessage("Default body")
34.setNegativeButton("Cancel",
35new DialogInterface.OnClickListener() {
36public void onClick(DialogInterface dialog, intwhich) {
37dialog.dismiss();
38}
39})
40.setPositiveButton("Confirm",
41new DialogInterface.OnClickListener() {
42public void onClick(DialogInterface dialog, intwhich) {
43CustomDialogActivity.this
44.dismissDialog(DEFAULT_DIALOG);
45}
46});
47dialog = alertBuilder.create();
48break;
49}
50return dialog;
51 }
