Android里的多媒体

一、通知：即显示在手机下滑框的消息。

       NotificationManager:通知管理器， 用来发送通知

                 有以下方法：

     (NotificationManager)getSystemService(NOTIFICATION_SERVICE):获得NotificationManager
     notify(int,Notification):发送通知，传入通知的id（每个通知都不能相同）和要发送的通知

       Notification.Builder:通知构建器，用来构建通知和设置通知各种参数

                 有以下方法：

		new Notification.Builder(Context):构建一个Notification.Builder
		builder.setSmallIcon(R.drawable.ic_launcher); //设置图标
		builder.setTicker("小红给你发来了一条信息");	  //显示最先在顶部收到的通知 
		builder.setContentTitle("通知"); 	//设置标题
		builder.setContentText("点击查看详细内容"); //消息内容
		builder.setWhen(System.currentTimeMillis()); //发送时间
		builder.setDefaults(Notification.DEFAULT_ALL); //设置默认的提示音，振动方式，光
		builder.setAutoCancel(true);//打开程序后图标消失
                builder.setSmallIcon(R.mipmap.ic_launcher)//设置小图标
                builder.setWhen(System.currentTimeMillis())//设置通知的时间

		//设置通知播放音频，指定路径下的音频
		builder.setSound(Uri.fromFile(new File("音频路径")));
		//设置通知振动：下标为偶数表示静止时长，奇数为振动时长，单位为毫秒
		//需在注册地方声明权限:
                //<uses-permission android:name="android.permission.VIBRATE" />
		long[] vibrates= {0,1000,1000,1000};//此时立即振动，然后静止一秒，再振动一次
		builder.setVibrate(vibrates);
		
		//设置通知响应的事件Activity,PendingIntent可以理解为延迟的Intent
		Intent intent =new Intent (this,NotificationLayout.class);
		PendingIntent pendingIntent =PendingIntent.getActivity(this, 0, intent,0);
		builder.setContentIntent(pendingIntent);
		
		//构建一条通知Notification
		Notification notification=builder.build();

        Notification:通知类,通过Notification.Builder的build()方法获得

           builder.build():构建一个Notification

完整例子：

public void onClick(View v) {
		switch(v.getId()) {
		case R.id.sendNotice:
			NotificationManager manager=            
                  (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
			Notification.Builder builder=new Notification.Builder(this);
			builder.setSmallIcon(R.drawable.ic_launcher); //设置图标
			builder.setTicker("小红给你发来了一条信息");	  //显示最先在顶部收到的通知 
			builder.setContentTitle("通知"); 	//设置标题
			builder.setContentText("点击查看详细内容"); //消息内容
			builder.setWhen(System.currentTimeMillis()); //发送时间
			builder.setDefaults(Notification.DEFAULT_ALL); //设置默认的提示音振动方式灯光
			builder.setAutoCancel(true);//打开程序后图标消失
			//设置通知播放音频，指定路径下的音频
			builder.setSound(Uri.fromFile(new 
                              File("/system/media/audio/ringtones/Basic_tone.ogg")));
			//设置通知振动：下标为偶数表示静止时长，奇数为振动时长，单位为毫秒
			//(需在注册地方声明权限:
                        //<uses-permission android:name="android.permission.VIBRATE" />)
			long[] vibrates= {0,1000,1000,1000};//此时立即振动，然后静止一秒，再振动一次
			builder.setVibrate(vibrates);
			
			//设置通知响应的事件Activity,PendingIntent可以理解为延迟的Intent
			Intent intent =new Intent (this,NotificationLayout.class);
			PendingIntent pendingIntent =PendingIntent.getActivity(this, 0, intent,0);
			builder.setContentIntent(pendingIntent);
			
			Notification notification=builder.build();
			manager.notify(1,notification);
			
		}
	}

二、短信

发送短信和接收短信涉及权限：

    <uses-permission android:name="android.permission.RECEIVE_SMS" />
    <uses-permission android:name="android.permission.SEND_SMS" />

       接收短信：当系统收到短信时会自动发送广播"android.provider.Telephony.SMS_RECEIVED"

       1、自定义广播接收器类

	class MessageReceiver extends BroadcastReceiver{
		//接收到系统短信广播进行的操作
		@Override
		public void onReceive(Context context, Intent intent) {
			Bundle bundle=intent.getExtras();
			Object[] pdus=(Object[])bundle.get("pdus");	//提取短信消息
			SmsMessage[] message=new SmsMessage[pdus.length];
	                String format = intent.getStringExtra("format");
			for(int i=0;i<message.length;i++) {
				message[i]=SmsMessage.createFromPdu((byte[])pdus[i],format);
			}
			String address=message[0].getOriginatingAddress();//获取发送方号码
			String fullMessage="";
			for(SmsMessage body:message) {
				fullMessage+=body.getMessageBody();//获取短信内容
			}
			sender.setText(address);
			content.setText(fullMessage);
		}
	}

      2、主活动onCreate()里注册广播接收器和onDestroy()取消注册广播接收器

protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		//接收短信部分
		sender=(TextView)findViewById(R.id.sender);
		content=(TextView)findViewById(R.id.content);
		messageReceiver=new MessageReceiver();
		intentfilter=new IntentFilter();
		intentfilter.addAction("android.provider.Telephony.SMS_RECEIVED");
		registerReceiver(messageReceiver, intentfilter);
    }
public void onDestroy() {
		super.onDestroy();
		//取消注册接收信息的广播接收器
		unregisterReceiver(messageReceiver);
    }

       发送短信：在onCreate()里利用SmsManager发送短信，增加了一个广播接收器判断短信是否发出
 

class sendStatusReceiver extends BroadcastReceiver{
		//接收发送广播状态的广播，进行判断
		@Override
		public void onReceive(Context context, Intent intent) {
			if(this.getResultCode()==RESULT_OK) {
				Toast.makeText(context, "Send succeed", Toast.LENGTH_SHORT).show();
			}else {
				Toast.makeText(context, "Send failed", Toast.LENGTH_SHORT).show();
			}
		}
}

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //发送短信部分
        to=(EditText)findViewById(R.id.to);
        msgInput=(EditText)findViewById(R.id.input);
        send=(Button)findViewById(R.id.send);
        intentfilter=new IntentFilter();
        intentfilter.addAction("SENT_SMS_ACTION");
        sendStatusReceiver=new sendStatusReceiver();
        registerReceiver(sendStatusReceiver,intentfilter);
        send.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                SmsManager smsManager=SmsManager.getDefault();
                Intent sendIntent=new Intent("SENT_SMS_ACTION");
                PendingIntent pi=PendingIntent.getBroadcast(MainActivity.this, 0,     
                 sendIntent, 0);
                smsManager.sendTextMessage(to.getText().toString(), null, 
                   msgInput.getText().toString(),pi, null);
            }
            
        });
}

public void onDestroy() {
	super.onDestroy();
	//取消注册接收发送信息状态变化的广播
	unregisterReceiver(sendStatusReceiver);
}

三、打开相机和打开相册：代码都有注释直接看代码

需要读权限
   

        <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

不需要写权限

        <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.mediatest.MainActivity" >

    <Button
        android:id="@+id/choose_photo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Choose photo" />

    <Button
        android:id="@+id/take_photo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Take photo" />

    <ImageView
        android:id="@+id/picture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal" />

</LinearLayout>

对应活动代码:

public class MainActivity extends Activity {
	private Button takePhoto;
	private Button choosePhoto;
	private ImageView picture;
	private Uri imageUri;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		takePhoto=(Button) findViewById(R.id.take_photo);
		picture = (ImageView) findViewById(R.id.picture);
		takePhoto.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				File outputPicture = new File(getExternalCacheDir(), "why.jpg");
		        if (outputPicture.exists()) {//如果照片文件存在则删除
		            outputPicture.delete();
		        }
		        try {
		            outputPicture.createNewFile();//创建一个新照片文件
		        } catch (IOException e) {
		            e.printStackTrace();
		        }
		        //"android.media.action.IMAGE_CAPTURE"用来隐式启动活动来启动相机
		        imageUri = Uri.fromFile(outputPicture);//将文件解析成Uri
		        Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
		        intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
		        startActivityForResult(intent, 1);//启动相机程序，并返回onActivityResult()方法
			}
		});
		choosePhoto=(Button)findViewById(R.id.choose_photo);
		choosePhoto.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				//将活
				Intent intent=new Intent("android.intent.action.GET_CONTENT");
				intent.setType("image/*");	//设置启动类型为照片，此时结果为3对应活动打开相册
				startActivityForResult(intent,3);
			}
			
		});
	}
	@Override
    protected void onActivityResult(int requestCode, int result, Intent data) {
        switch (requestCode) {
    		//裁剪照片
            case 1:
                if(result==RESULT_OK) {
                	Intent intent=new Intent("com.android.camera.action.CROP");
                	//Data是指储存的数据（即当前照片的Uri）
                	//Type是启动的类型：目前为照片（一般在需要裁剪照片和启动相机时使用）
                	intent.setDataAndType(imageUri, "image/*");
                	intent.putExtra("scale", true);
                	intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                	startActivityForResult(intent,2);
                }
            //压缩照片并显示
            case 2:
            	if (result == RESULT_OK) {
                    try {
                    	//获取图片
                        Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));
                        //压缩图片在手机存储空间的内存  
                        ByteArrayOutputStream out = new ByteArrayOutputStream();
                        bitmap.compress(Bitmap.CompressFormat.JPEG, 80, out);//80指保留80品质，压缩20品质
                        
                        //显示照片
                        picture.setImageBitmap(bitmap);

                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                }
                break;
            //打开相册
            case 3:
            	if (result == RESULT_OK) {
            		//必须重写handleImageOnKitKat(Intent)和handleImageBeforeKitKat(Intent)方法
	            	if(Build.VERSION.SDK_INT>=19) {
	                    //4.4（API 19）以上版本实现打开相册
	                    handleImageOnKitKat(data);
	            	}
	            	else {
	            		//4.4以下版本实现打开相册
	            		handleImageBeforeKitKat(data);
	            	}
            	}
                break;
        }
    }

    private void handleImageBeforeKitKat(Intent data) {
		Uri uri=data.getData();
		String imagePath=getImagePath(uri,null);
		showImage(imagePath);
	}
	@TargetApi(Build.VERSION_CODES.KITKAT)
	@SuppressLint("NewApi")
	private void handleImageOnKitKat(Intent data) {
        //获取资源定位符
        Uri uri = data.getData();
        String imagePath=getImagePath(uri);
        showImage(imagePath);
    }
	//解析Uri返回图片路径
    @SuppressLint("NewApi")
	private String getImagePath(Uri uri) {
    	//选择图片路径
        String imagePath = null;
        if (DocumentsContract.isDocumentUri(this, uri)) {
            String docId = DocumentsContract.getDocumentId(uri);
            if ("com.android.providers.media.documents".equals(uri.getAuthority())) {
                String id = docId.split(":")[1];
                String selection = MediaStore.Images.Media._ID + "=" + id;
                imagePath = getImagePath(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection);
            } else if ("com.android.providers.downloads.documents".equals(uri.getAuthority())) {
                Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(docId));
                imagePath = getImagePath(contentUri, null);
            }

        } else if ("content".equalsIgnoreCase(uri.getScheme())) {
            imagePath = getImagePath(uri, null);
        } else if ("file".equalsIgnoreCase(uri.getScheme())) {
            imagePath = uri.getPath();
        }
		return imagePath;
    }
    //子方法：根据Uri和selection返回图片路径
    private String getImagePath(Uri externalContentUri, String selection) {
        String path = null;
        Cursor cursor = getContentResolver().query(externalContentUri, null, selection, null, null);
        if (cursor != null) {
            if (cursor.moveToFirst()) {
                path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
            }
            cursor.close();
        }
        return path;
    }
    //根据图片路径显示图片
    private void showImage(String imagePath) {
        if (imagePath != null) {
            Bitmap bitmap = BitmapFactory.decodeFile(imagePath);
            /*
               setlmageBitmap(Bitmap bm)：使用 Bitmap 位图设置该 ImageView 显示的图片。

			   setlmageDrawable(Drawable drawable)：使用 Drawable 对象设置该 ImageView 显示的图片。

			   setlmageResource(int resld)：使用图片资源ID设置该ImageView显示的图片。

			   setlmageURI(Uri uri)：使用图片的URI设置该ImageView显示的图片。
             */
            picture.setImageBitmap(bitmap);
        } else {
            Toast.makeText(this, "没有找到对应图片", Toast.LENGTH_SHORT).show();
        }
    }
}

四、播放音频和视频

补充知识：

1、需要读取权限

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

2、获取系统内存根目录位置方法和SD卡根目录位置方法

//内存根目录获取方法：Environment.getExternalStorageDirectory()

//获取SD卡根路径方法：
public static String getSDPath(Context context) {  

      StorageManager mStorageManager = (StorageManager)
                context.getSystemService(Context.STORAGE_SERVICE);
        Class<?> storageVolumeClazz = null;
        try {
            storageVolumeClazz = Class.forName("android.os.storage.StorageVolume");
            Method getVolumeList = mStorageManager.getClass().getMethod("getVolumeList");
            Method getPath = storageVolumeClazz.getMethod("getPath");
            Method isRemovable = storageVolumeClazz.getMethod("isRemovable");
            Object result = getVolumeList.invoke(mStorageManager);
            final int length = Array.getLength(result);
            for (int i = 0; i < length; i++) {
                Object storageVolumeElement = Array.get(result, i);
                String path = (String) getPath.invoke(storageVolumeElement);
                boolean removable = (Boolean) isRemovable.invoke(storageVolumeElement);
                if (removable) {
                    return path;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
}

1、播放音频：使用MediaPlayer类

           MediaPlayer类有以下方法：

           setDataSource():设置播放音频文件位置

           prepare():在开始播放前调用此方法完成准备工作

           start():开始或继续播放音频

           pause():暂停播放音频

           reset():将MediaPlayer对象重置到刚刚创建状态

           seekTo():从指定位置开始播放音频

           stop():停止播放音频

           release():释放掉与MediaPlayer对象相关资源

           isPlaying():判断是否正在播放音频

           getDuration():获取载入的音频文件时长

2、播放视频：使用VideoView类

           VideoView类有以下方法：

           setVideoPath():设置视频文件位置

           start():开始或继续播放视频

           pause():暂停播放视频

           resume():将视频从头开始播放

           seekTo():从指定位置开始播放视频

           isPlaying():判断是否正在播放视频

           getDuration():获取载入的视频文件时长

播放音频完整代码演示

public class MusicActivity extends Activity implements OnClickListener{
	private Button play;
	private Button pause;
	private Button stop;
	private MediaPlayer mediaPlayer=new MediaPlayer();
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.music);
		play=(Button)findViewById(R.id.play);
		pause=(Button)findViewById(R.id.pause);
		stop=(Button)findViewById(R.id.stop);
		play.setOnClickListener(this);
		pause.setOnClickListener(this);
		stop.setOnClickListener(this);
		initMediaPlayer();
	}




//获取SD卡根路径方法：
public static String getSDPath(Context context) {  

      StorageManager mStorageManager = (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);
        Class<?> storageVolumeClazz = null;
        try {
            storageVolumeClazz = Class.forName("android.os.storage.StorageVolume");
            Method getVolumeList = mStorageManager.getClass().getMethod("getVolumeList");
            Method getPath = storageVolumeClazz.getMethod("getPath");
            Method isRemovable = storageVolumeClazz.getMethod("isRemovable");
            Object result = getVolumeList.invoke(mStorageManager);
            final int length = Array.getLength(result);
            for (int i = 0; i < length; i++) {
                Object storageVolumeElement = Array.get(result, i);
                String path = (String) getPath.invoke(storageVolumeElement);
                boolean removable = (Boolean) isRemovable.invoke(storageVolumeElement);
                if (removable) {
                    return path;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
}
	@Override
	public void onClick(View v) {
		switch(v.getId()) {
		case R.id.play:
			if(!mediaPlayer.isPlaying()) {
				mediaPlayer.start();
			}break;
		case R.id.pause:
			if(mediaPlayer.isPlaying()) {
				mediaPlayer.pause();
			}break;
		case R.id.stop:
			if(mediaPlayer.isPlaying()) {
				mediaPlayer.reset();
				initMediaPlayer();
			}break;
		default:break;
		}
	}
	public void onDestroy() {
		super.onDestroy();
		if(mediaPlayer!=null) {
			mediaPlayer.stop();
			mediaPlayer.release();
		}
	}
	//初始化音频文件方法：设置音频位置，完成准备工作
	private void initMediaPlayer() {
		try {
			File file=new File(getSDPath(this),"aiying.mp3");
			mediaPlayer.setDataSource(file.getPath());
			mediaPlayer.prepare();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

播放视频完整代码演示

public class VedioActivity extends Activity implements OnClickListener{
	private VideoView videoView;
	private Button play;
	private Button pause;
	private Button replay;
	
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.vedio);
		videoView=(VideoView)findViewById(R.id.videoView1);
		play=(Button)findViewById(R.id.play_vieo);
		pause=(Button)findViewById(R.id.pause_vieo);
		replay=(Button)findViewById(R.id.replay);
		play.setOnClickListener(this);
		pause.setOnClickListener(this);
		replay.setOnClickListener(this);
		initVideoPath();
	}
	private void initVideoPath() {
		File file=new File(Environment.getExternalStorageDirectory(),"tiao.mp4");
		videoView.setVideoPath(file.getPath());
	}
	@Override
	public void onClick(View v) {
		switch(v.getId()) {
		case R.id.play_vieo:
			if(!videoView.isPlaying()) {
				videoView.start();
			}
			break;
		case R.id.pause_vieo:
			if(videoView.isPlaying()) {
				videoView.pause();
			}
			break;
		case R.id.replay:
			if(videoView.isPlaying()) {
				videoView.resume();
			}
			break;
		}
	}
	public void onDestroy() {
		super.onDestroy();
		if(videoView!=null) {
			videoView.suspend();
		}
	}
}