Android应用开发--MP3音乐播放器代码实现（二）
Android应用开发--MP3音乐播放器代码实现（二）
2013年5月25日 简、美音乐播放器开发
小巫在这里罗列这个播放器已经实现的功能：
1. 自动显示音乐列表
2. 点击列表播放音乐
3. 长按列表弹出对话框
4. 暂停音乐
5. 上一首音乐
6. 下一首音乐
7. 自动播放下一首歌曲
8. 单曲循环
9. 全部循环
10. 随机播放
以上所有功能将会分为两篇博文来讲解，首先是主界面的，接着是播放界面的。在这里要说明一点，以上功能是小巫自己一点一点调试才实现的，并不能完全排除考虑不周的地方，原本这个软件实现起来并不太难，但确实要考虑到很多细节的地方，播放状态的切换和控制就是一块，也花了我不少实现，之前还很苦恼实现自己想要的效果，但后来还是经过思考和调试把功能实现。所以说，开发是一个需要很耐心的过程，各位童鞋，如果真正喜欢编程的话，想要做出一些小作品的话，那就好好掂量自己的耐心吧，好了，废话不多说，先贴一大段代码，后面在慢慢把需要注意的地方说一下。
主界面效果图：
以上界面的效果怎么实现的？
很简单的，就是ListView的数据填充，但要填的的东西就要考虑了，怎么把数据从SQLite中获取，小巫封装了一个工具类，用来获取与MP3相关的数据。
==>MediaUtils
package com.wwj.sb.utils;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import android.content.Context;
import android.database.Cursor;
import android.provider.MediaStore;
import com.wwj.sb.domain.Mp3Info;
public class MediaUtil {
/**
* 用于从数据库中查询歌曲的信息，保存在List当中
*
* @return
*/
public static List<Mp3Info> getMp3Infos(Context context) {
Cursor cursor = context.getContentResolver().query(
MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null, null,
MediaStore.Audio.Media.DEFAULT_SORT_ORDER);
List<Mp3Info> mp3Infos = new ArrayList<Mp3Info>();
for (int i = 0; i < cursor.getCount(); i++) {
cursor.moveToNext();
Mp3Info mp3Info = new Mp3Info();
long id = cursor.getLong(cursor
.getColumnIndex(MediaStore.Audio.Media._ID)); //音乐id
String title = cursor.getString((cursor
.getColumnIndex(MediaStore.Audio.Media.TITLE))); //音乐标题
String artist = cursor.getString(cursor
.getColumnIndex(MediaStore.Audio.Media.ARTIST)); //艺术家
long duration = cursor.getLong(cursor
.getColumnIndex(MediaStore.Audio.Media.DURATION)); //时长
long size = cursor.getLong(cursor
.getColumnIndex(MediaStore.Audio.Media.SIZE)); //文件大小
String url = cursor.getString(cursor
.getColumnIndex(MediaStore.Audio.Media.DATA)); //文件路径
int isMusic = cursor.getInt(cursor
.getColumnIndex(MediaStore.Audio.Media.IS_MUSIC)); //是否为音乐
if (isMusic != 0) { //只把音乐添加到集合当中
mp3Info.setId(id);
mp3Info.setTitle(title);
mp3Info.setArtist(artist);
mp3Info.setDuration(duration);
mp3Info.setSize(size);
mp3Info.setUrl(url);
mp3Infos.add(mp3Info);
}
}
return mp3Infos;
}
/**
* 往List集合中添加Map对象数据，每一个Map对象存放一首音乐的所有属性
* @param mp3Infos
* @return
*/
public static List<HashMap<String, String>> getMusicMaps(
List<Mp3Info> mp3Infos) {
List<HashMap<String, String>> mp3list = new ArrayList<HashMap<String, String>>();
for (Iterator iterator = mp3Infos.iterator(); iterator.hasNext();) {
Mp3Info mp3Info = (Mp3Info) iterator.next();
HashMap<String, String> map = new HashMap<String, String>();
map.put("title", mp3Info.getTitle());
map.put("Artist", mp3Info.getArtist());
map.put("duration", formatTime(mp3Info.getDuration()));
map.put("size", String.valueOf(mp3Info.getSize()));
map.put("url", mp3Info.getUrl());
mp3list.add(map);
}
return mp3list;
}
/**
* 格式化时间，将毫秒转换为分:秒格式
* @param time
* @return
*/
public static String formatTime(long time) {
String min = time / (1000 * 60) + "";
String sec = time % (1000 * 60) + "";
if (min.length() < 2) {
min = "0" + time / (1000 * 60) + "";
} else {
min = time / (1000 * 60) + "";
}
if (sec.length() == 4) {
sec = "0" + (time % (1000 * 60)) + "";
} else if (sec.length() == 3) {
sec = "00" + (time % (1000 * 60)) + "";
} else if (sec.length() == 2) {
sec = "000" + (time % (1000 * 60)) + "";
} else if (sec.length() == 1) {
sec = "0000" + (time % (1000 * 60)) + "";
}
return min + ":" + sec.trim().substring(0, 2);
}
}
好吧，来重头戏了，一大段代码来袭。
HomeActivity.Java
package com.wwj.sb.activity;
import java.util.HashMap;
import java.util.List;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Vibrator;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnCreateContextMenuListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;
import com.wwj.sb.domain.AppConstant;
import com.wwj.sb.domain.Mp3Info;
import com.wwj.sb.service.PlayerService;
import com.wwj.sb.utils.ConstantUtil;
import com.wwj.sb.utils.CustomDialog;
import com.wwj.sb.utils.MediaUtil;
/**
* 2013/5/7
* 简、美音乐播放器
* @author wwj
*
*/
public class HomeActivity extends Activity {
private ListView mMusiclist; // 音乐列表
private List<Mp3Info> mp3Infos = null;
private SimpleAdapter mAdapter; // 简单适配器
private Button previousBtn; // 上一首
private Button repeatBtn; // 重复（单曲循环、全部循环）
private Button playBtn; // 播放（播放、暂停）
private Button shuffleBtn; // 随机播放
private Button nextBtn; // 下一首
private TextView musicTitle;//歌曲标题
private TextView musicDuration; //歌曲时间
private Button musicPlaying; //歌曲专辑
private int repeatState; //循环标识
private final int isCurrentRepeat = 1; // 单曲循环
private final int isAllRepeat = 2; // 全部循环
private final int isNoneRepeat = 3; // 无重复播放
private boolean isFirstTime = true;
private boolean isPlaying; // 正在播放
private boolean isPause; // 暂停
private boolean isNoneShuffle = true; // 顺序播放
private boolean isShuffle = false; // 随机播放
private int listPosition = 0; //标识列表位置
private HomeReceiver homeReceiver; //自定义的广播接收器
//一系列动作
public static final String UPDATE_ACTION = "com.wwj.action.UPDATE_ACTION";
public static final String CTL_ACTION = "com.wwj.action.CTL_ACTION";
public static final String MUSIC_CURRENT = "com.wwj.action.MUSIC_CURRENT";
public static final String MUSIC_DURATION = "com.wwj.action.MUSIC_DURATION";
public static final String REPEAT_ACTION = "com.wwj.action.REPEAT_ACTION";
public static final String SHUFFLE_ACTION = "com.wwj.action.SHUFFLE_ACTION";
private int currentTime;
private int duration;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home_activity_layout);
mMusiclist = (ListView) findViewById(R.id.music_list);
mMusiclist.setOnItemClickListener(new MusicListItemClickListener());
mMusiclist.setOnCreateContextMenuListener(new MusicListItemContextMenuListener());
mp3Infos = MediaUtil.getMp3Infos(getApplicationContext()); //获取歌曲对象集合
setListAdpter(MediaUtil.getMusicMaps(mp3Infos)); //显示歌曲列表
findViewById(); //找到界面上的每一个控件
setViewOnclickListener(); //为一些控件设置监听器
repeatState = isNoneRepeat; // 初始状态为无重复播放状态
homeReceiver = new HomeReceiver();
// 创建IntentFilter
IntentFilter filter = new IntentFilter();
// 指定BroadcastReceiver监听的Action
filter.addAction(UPDATE_ACTION);
filter.addAction(MUSIC_CURRENT);
filter.addAction(MUSIC_DURATION);
filter.addAction(REPEAT_ACTION);
filter.addAction(SHUFFLE_ACTION);
// 注册BroadcastReceiver
registerReceiver(homeReceiver, filter);
}
/**
* 从界面上根据id获取按钮
*/
private void findViewById() {
previousBtn = (Button) findViewById(R.id.previous_music);
repeatBtn = (Button) findViewById(R.id.repeat_music);
playBtn = (Button) findViewById(R.id.play_music);
shuffleBtn = (Button) findViewById(R.id.shuffle_music);
nextBtn = (Button) findViewById(R.id.next_music);
musicTitle = (TextView) findViewById(R.id.music_title);
musicDuration = (TextView) findViewById(R.id.music_duration);
musicPlaying = (Button) findViewById(R.id.playing);
}
/**
* 给每一个按钮设置监听器
*/
private void setViewOnclickListener() {
ViewOnClickListener viewOnClickListener = new ViewOnClickListener();
previousBtn.setOnClickListener(viewOnClickListener);
repeatBtn.setOnClickListener(viewOnClickListener);
playBtn.setOnClickListener(viewOnClickListener);
shuffleBtn.setOnClickListener(viewOnClickListener);
nextBtn.setOnClickListener(viewOnClickListener);
musicPlaying.setOnClickListener(viewOnClickListener);
}
private class ViewOnClickListener implements OnClickListener {
Intent intent = new Intent();
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.previous_music: // 上一首
playBtn.setBackgroundResource(R.drawable.play_selector);
isFirstTime = false;
isPlaying = true;
isPause = false;
previous();
break;
case R.id.repeat_music: // 重复播放
if (repeatState == isNoneRepeat) {
repeat_one();
shuffleBtn.setClickable(false);
repeatState = isCurrentRepeat;
} else if (repeatState == isCurrentRepeat) {
repeat_all();
shuffleBtn.setClickable(false);
repeatState = isAllRepeat;
} else if (repeatState == isAllRepeat) {
repeat_none();
shuffleBtn.setClickable(true);
repeatState = isNoneRepeat;
}
switch (repeatState) {
case isCurrentRepeat: // 单曲循环
repeatBtn
.setBackgroundResource(R.drawable.repeat_current_selector);
Toast.makeText(HomeActivity.this, R.string.repeat_current,
Toast.LENGTH_SHORT).show();
break;
case isAllRepeat: // 全部循环
repeatBtn
.setBackgroundResource(R.drawable.repeat_all_selector);
Toast.makeText(HomeActivity.this, R.string.repeat_all,
Toast.LENGTH_SHORT).show();
break;
case isNoneRepeat: // 无重复
repeatBtn
.setBackgroundResource(R.drawable.repeat_none_selector);
Toast.makeText(HomeActivity.this, R.string.repeat_none,
Toast.LENGTH_SHORT).show();
break;
}
break;
case R.id.play_music: // 播放音乐
if(isFirstTime) {
play();
isFirstTime = false;
isPlaying = true;
isPause = false;
} else {
if (isPlaying) {
playBtn.setBackgroundResource(R.drawable.pause_selector);
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("MSG", AppConstant.PlayerMsg.PAUSE_MSG);
startService(intent);
isPlaying = false;
isPause = true;
} else if (isPause) {
playBtn.setBackgroundResource(R.drawable.play_selector);
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("MSG", AppConstant.PlayerMsg.CONTINUE_MSG);
startService(intent);
isPause = false;
isPlaying = true;
}
}
break;
case R.id.shuffle_music: // 随机播放
if (isNoneShuffle) {
shuffleBtn
.setBackgroundResource(R.drawable.shuffle_selector);
Toast.makeText(HomeActivity.this, R.string.shuffle,
Toast.LENGTH_SHORT).show();
isNoneShuffle = false;
isShuffle = true;
shuffleMusic();
repeatBtn.setClickable(false);
} else if (isShuffle) {
shuffleBtn
.setBackgroundResource(R.drawable.shuffle_none_selector);
Toast.makeText(HomeActivity.this, R.string.shuffle_none,
Toast.LENGTH_SHORT).show();
isShuffle = false;
isNoneShuffle = true;
repeatBtn.setClickable(true);
}
break;
case R.id.next_music: // 下一首
playBtn.setBackgroundResource(R.drawable.play_selector);
isFirstTime = false;
isPlaying = true;
isPause = false;
next();
break;
case R.id.playing: //正在播放
Mp3Info mp3Info = mp3Infos.get(listPosition);
Intent intent = new Intent(HomeActivity.this, PlayerActivity.class);
intent.putExtra("title", mp3Info.getTitle());
intent.putExtra("url", mp3Info.getUrl());
intent.putExtra("artist", mp3Info.getArtist());
intent.putExtra("listPosition", listPosition);
intent.putExtra("currentTime", currentTime);
intent.putExtra("duration", duration);
intent.putExtra("MSG", AppConstant.PlayerMsg.PLAYING_MSG);
startActivity(intent);
break;
}
}
}
private class MusicListItemClickListener implements OnItemClickListener {
/**
* 点击列表播放音乐
*/
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
listPosition = position;
playMusic(listPosition);
}
}
public class MusicListItemContextMenuListener implements OnCreateContextMenuListener {
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
Vibrator vibrator = (Vibrator) getSystemService(Service.VIBRATOR_SERVICE);
vibrator.vibrate(50); //长按振动
musicListItemDialog(); //长按后弹出的对话框
}
}
/**
* 填充列表
*
* @param mp3Infos
*/
public void setListAdpter(List<HashMap<String, String>> mp3list) {
mAdapter = new SimpleAdapter(this, mp3list,
R.layout.music_list_item_layout, new String[] { "title",
"Artist", "duration" }, new int[] { R.id.music_title,
R.id.music_Artist, R.id.music_duration });
mMusiclist.setAdapter(mAdapter);
}
/**
* 下一首歌曲
*/
public void next() {
listPosition = listPosition + 1;
if(listPosition <= mp3Infos.size() - 1) {
Mp3Info mp3Info = mp3Infos.get(listPosition);
musicTitle.setText(mp3Info.getTitle());
Intent intent = new Intent();
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("listPosition", listPosition);
intent.putExtra("url", mp3Info.getUrl());
intent.putExtra("MSG", AppConstant.PlayerMsg.NEXT_MSG);
startService(intent);
} else {
Toast.makeText(HomeActivity.this, "没有下一首了", Toast.LENGTH_SHORT).show();
}
}
/**
* 上一首歌曲
*/
public void previous() {
listPosition = listPosition - 1;
if(listPosition >= 0) {
Mp3Info mp3Info = mp3Infos.get(listPosition);
musicTitle.setText(mp3Info.getTitle());
Intent intent = new Intent();
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("listPosition", listPosition);
intent.putExtra("url", mp3Info.getUrl());
intent.putExtra("MSG", AppConstant.PlayerMsg.PRIVIOUS_MSG);
startService(intent);
}else {
Toast.makeText(HomeActivity.this, "没有上一首了", Toast.LENGTH_SHORT).show();
}
}
public void play() {
playBtn.setBackgroundResource(R.drawable.play_selector);
Mp3Info mp3Info = mp3Infos.get(listPosition);
musicTitle.setText(mp3Info.getTitle());
Intent intent = new Intent();
intent.setAction("com.wwj.media.MUSIC_SERVICE");
intent.putExtra("listPosition", 0);
intent.putExtra("url", mp3Info.getUrl());
intent.putExtra("MSG", AppConstant.PlayerMsg.PLAY_MSG);
startService(intent);
}
/**
* 单曲循环
*/
public void repeat_one() {
Intent intent = new Intent(CTL_ACTION);
intent.putExtra("control", 1);
sendBroadcast(intent);
}
/**
* 全部循环
*/
public void repeat_all() {
Intent intent = new Intent(CTL_ACTION);
intent.putExtra("control", 2);
sendBroadcast(intent);
}
/**
* 顺序播放
*/
public void repeat_none() {
Intent intent = new Intent(CTL_ACTION);
intent.putExtra("control", 3);
sendBroadcast(intent);
}
/**
* 随机播放
*/
public void shuffleMusic() {
Intent intent = new Intent(CTL_ACTION);
intent.putExtra("control", 4);
sendBroadcast(intent);
}
public void musicListItemDialog() {
String[] menuItems = new String[]{"播放音乐","设为铃声","查看详情"};
ListView menuList = new ListView(HomeActivity.this);
menuList.setCacheColorHint(Color.TRANSPARENT);
menuList.setDividerHeight(1);
menuList.setAdapter(new ArrayAdapter<String>(HomeActivity.this, R.layout.context_dialog_layout, R.id.dialogText, menuItems));
menuList.setLayoutParams(new LayoutParams(ConstantUtil.getScreen(HomeActivity.this)[0] / 2, LayoutParams.WRAP_CONTENT));
final CustomDialog customDialog = new CustomDialog.Builder(HomeActivity.this).setTitle(R.string.operation).setView(menuList).create();
customDialog.show();
menuList.setOnItemClickListener( new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
customDialog.cancel();
customDialog.dismiss();
}
});
}
public void playMusic(int listPosition) {
if (mp3Infos != null) {
Mp3Info mp3Info = mp3Infos.get(listPosition);
musicTitle.setText(mp3Info.getTitle());
Intent intent = new Intent(HomeActivity.this, PlayerActivity.class);
intent.putExtra("title", mp3Info.getTitle());
intent.putExtra("url", mp3Info.getUrl());
intent.putExtra("artist", mp3Info.getArtist());
intent.putExtra("listPosition", listPosition);
intent.putExtra("currentTime", currentTime);
intent.putExtra("repeatState", repeatState);
intent.putExtra("shuffleState", isShuffle);
intent.putExtra("MSG", AppConstant.PlayerMsg.PLAY_MSG);
startActivity(intent);
}
}
@Override
protected void onStop() {
// TODO Auto-generated method stub
super.onStop();
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
}
/**
* 按返回键弹出对话框确定退出
*/
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK
&& event.getAction() == KeyEvent.ACTION_DOWN) {
new AlertDialog.Builder(this)
.setIcon(R.drawable.ic_launcher)
.setTitle("退出")
.setMessage("您确定要退出？")
.setNegativeButton("取消", null)
.setPositiveButton("确定",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
finish();
Intent intent = new Intent(
HomeActivity.this,
PlayerService.class);
unregisterReceiver(homeReceiver);
stopService(intent); // 停止后台服务
}
}).show();
}
return super.onKeyDown(keyCode, event);
}
//自定义的BroadcastReceiver，负责监听从Service传回来的广播
public class HomeReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if(action.equals(MUSIC_CURRENT)){
//currentTime代表当前播放的时间
currentTime = intent.getIntExtra("currentTime", -1);
musicDuration.setText(MediaUtil.formatTime(currentTime));
} else if (action.equals(MUSIC_DURATION)) {
duration = intent.getIntExtra("duration", -1);
}
else if(action.equals(UPDATE_ACTION)) {
//获取Intent中的current消息，current代表当前正在播放的歌曲
listPosition = intent.getIntExtra("current", -1);
if(listPosition >= 0) {
musicTitle.setText(mp3Infos.get(listPosition).getTitle());
}
}else if(action.equals(REPEAT_ACTION)) {
repeatState = intent.getIntExtra("repeatState", -1);
switch (repeatState) {
case isCurrentRepeat: // 单曲循环
repeatBtn
.setBackgroundResource(R.drawable.repeat_current_selector);
shuffleBtn.setClickable(false);
break;
case isAllRepeat: // 全部循环
repeatBtn
.setBackgroundResource(R.drawable.repeat_all_selector);
shuffleBtn.setClickable(false);
break;
case isNoneRepeat: // 无重复
repeatBtn
.setBackgroundResource(R.drawable.repeat_none_selector);
shuffleBtn.setClickable(true);
break;
}
}
else if(action.equals(SHUFFLE_ACTION)) {
isShuffle = intent.getBooleanExtra("shuffleState", false);
if(isShuffle) {
isNoneShuffle = false;
shuffleBtn.setBackgroundResource(R.drawable.shuffle_selector);
repeatBtn.setClickable(false);
} else {
isNoneShuffle = true;
shuffleBtn.setBackgroundResource(R.drawable.shuffle_none_selector);
repeatBtn.setClickable(true);
}
}
}
}
}
到这里，要开讲啦。
以下是需要注意的几点：
1. 音乐是通过Service来播放的，Activity通过启动服务来实现在后台播放音乐。
2. Activity中自定义了一个广播接收器，需要进行intent过滤器的定义，动作的添加，注册广播接收器：
homeReceiver = new HomeReceiver();
// 创建IntentFilter
IntentFilter filter = new IntentFilter();
// 指定BroadcastReceiver监听的Action
filter.addAction(UPDATE_ACTION);
filter.addAction(MUSIC_CURRENT);
filter.addAction(MUSIC_DURATION);
filter.addAction(REPEAT_ACTION);
filter.addAction(SHUFFLE_ACTION);
// 注册BroadcastReceiver
registerReceiver(homeReceiver, filter);
3. 在广播接收器类当中对动作进行处理，比如实现时间的更新和标题的更新等。
4. 这里还要注意按钮触发，播放状态的改变，比如音乐循环，有三种状态：单曲、全部循环、顺序，每切换一个状态都要向服务发送一条广播，通知它要改变状态。
5. 点击列表的时候，会跳入到播放界面的Activity中，要注意用intent来传递参数，注意每个参数的用途，比如title、url、MSG，就分别代表标题、路径、播放状态。
6. 长按列表会弹出自定义对话框，也会有短暂的震动效果，自定义对话框需要自行实现。这里我也贴一下实现代码吧。
package com.wwj.sb.utils;
import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import com.wwj.sb.activity.R;
/**
* 自定义对话框类
*
* @author wwj
*
*/
public class CustomDialog extends Dialog {
public CustomDialog(Context context) {
super(context);
}
public CustomDialog(Context context, int theme) {
super(context, theme);
}
public static class Builder {
private Context context;
private int mIcon = -1; // 提示图标
private CharSequence mTitle; // 提示标题
private CharSequence mMessage; // 提示内容
private CharSequence mPositiveButtonText; // 确定按钮文本
private CharSequence mNegativeButtonText; // 取消按钮文本
private CharSequence mNeutralButtonText; // 中间按钮文本
private boolean mCancelable = true; // 是否启用取消键
private int mViewSpacingLeft;
private int mViewSpacingTop;
private int mViewSpacingRight;
private int mViewSpacingBottom;
private boolean mViewSpacingSpecified = false;
// 提示内容View
private View mView;
// 各种触发事件
private OnClickListener mPositiveButtonClickListener,
mNegativeButtonClickListener, mNeutralButtonClickListener;
private OnCancelListener mCancelListener; // 取消键事件
private OnKeyListener mKeyListener; // 按键处理
public Builder(Context context) {
this.context = context;
}
public Builder setMessage(CharSequence message) {
this.mMessage = message;
return this;
}
public Builder setMessage(int message) {
this.mMessage = context.getText(message);
return this;
}
public Builder setTitle(int title) {
this.mTitle = context.getText(title);
return this;
}
public Builder setTitle(CharSequence title) {
this.mTitle = title;
return this;
}
public Builder setIcon(int icon) {
this.mIcon = icon;
return this;
}
public Builder setView(View view) {
this.mView = view;
mViewSpacingSpecified = false;
return this;
}
public Builder setView(View view, int left, int top, int right,
int bottom) {
this.mView = view;
this.mViewSpacingLeft = left;
this.mViewSpacingTop = top;
this.mViewSpacingRight = right;
this.mViewSpacingBottom = bottom;
mViewSpacingSpecified = true;
return this;
}
public Builder setPositonButton(int textId,
final OnClickListener listener) {
this.mPositiveButtonText = context.getText(textId);
this.mPositiveButtonClickListener = listener;
return this;
}
public Builder setPostionButton(String text,
final OnClickListener listener) {
this.mPositiveButtonText = text;
this.mPositiveButtonClickListener = listener;
return this;
}
public Builder setNeutralButton(int textId,
final OnClickListener listener) {
this.mNeutralButtonText = context.getText(textId);
this.mNeutralButtonClickListener = listener;
return this;
}
public Builder setNeutralButton(String text, final OnClickListener listener) {
this.mNeutralButtonText = text;
this.mNeutralButtonClickListener = listener;
return this;
}
public Builder setNegativeButton(int textId,
final OnClickListener listener) {
this.mNegativeButtonText = context.getText(textId);
this.mNegativeButtonClickListener = listener;
return this;
}
public Builder setNegativeButton(String text,
final OnClickListener listener) {
this.mNegativeButtonText = text;
this.mNegativeButtonClickListener = listener;
return this;
}
public Builder setCancelable(boolean cancelable) {
this.mCancelable = cancelable;
return this;
}
public Builder setOnCancelListener(OnCancelListener listener) {
this.mCancelListener = listener;
return this;
}
public Builder setOnKeyListener(OnKeyListener listener) {
this.mKeyListener = listener;
return this;
}
public CustomDialog create() {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final CustomDialog dialog = new CustomDialog(context, R.style.CustomDialog);
dialog.setCancelable(mCancelable);
//设置取消键事件
if(mCancelListener != null) {
dialog.setOnCancelListener(mCancelListener);
}
//设置键盘监听事件
if(mKeyListener != null) {
dialog.setOnKeyListener(mKeyListener);
}
//获取对话框布局
View layout = inflater.inflate(R.layout.alert_dialog, (ViewGroup)(((Activity)context).findViewById(R.id.parentPanel)));
layout.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
//设置标题
((TextView) layout.findViewById(R.id.alertTitle)).setText(mTitle);
//设置图标
if(mIcon != -1) {
((ImageView) layout.findViewById(R.id.icon))
.setBackgroundResource(mIcon);
}
int count = 0;
//设置确定按钮
if(setButton(layout, mPositiveButtonText, R.id.button1, dialog, mPositiveButtonClickListener)) count++;
// 设置拒绝按钮
if(setButton(layout, mNegativeButtonText, R.id.button2, dialog, mNegativeButtonClickListener)) count++;
// 设置中间按钮
if(setButton(layout, mNeutralButtonText, R.id.button3, dialog, mNeutralButtonClickListener)) count++;
if(count == 0) {
layout.findViewById(R.id.buttonPanel).setVisibility(View.GONE);
}
//一个按钮时，显示两边空间
if(count == 1) {
layout.findViewById(R.id.leftSpacer)
.setVisibility(View.INVISIBLE);
layout.findViewById(R.id.rightSpacer).setVisibility(View.INVISIBLE);
}
//设置提示消息
if(!TextUtils.isEmpty(mMessage)) {
((TextView)layout.findViewById(R.id.message))
.setText(mMessage);
} else {
((LinearLayout) layout.findViewById(R.id.contentPanel))
.setVisibility(View.GONE);
}
//设置提示内容布局
if(mView != null) {
final FrameLayout customPanel = (FrameLayout) layout
.findViewById(R.id.customPanel);
if(mViewSpacingSpecified) {
customPanel.setPadding(mViewSpacingLeft, mViewSpacingTop, mViewSpacingRight, mViewSpacingBottom);
}
customPanel.addView(mView);
} else {
((FrameLayout) layout.findViewById(R.id.customPanel))
.setVisibility(View.GONE);
}
dialog.setContentView(layout);
return dialog;
}
public CustomDialog show() {
CustomDialog dialog = create();
dialog.show();
return dialog;
}
private boolean setButton(View layout, CharSequence mPositiveButtonText, int id, final Dialog dialog, final OnClickListener listener) {
if(!TextUtils.isEmpty(mPositiveButtonText)) {
final Button button = (Button) layout.findViewById(id);
button.setText(mPositiveButtonText);
if(listener != null) {
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
listener.onClick(dialog, DialogInterface.BUTTON_POSITIVE);
}
});
} else {
//默认事件为关闭对话框
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dialog.cancel();
dialog.dismiss();
}
});
}
return true;
} else {
layout.findViewById(id).setVisibility(View.GONE);
return false;
}
}
}
}
关于主界面的业务逻辑具体实现和需要注意的地方，小巫已经说完了。其实最重要的是要写好服务类，下一篇播放将会给童鞋们介绍服务类的实现。最后感谢大家的关注。