Android 开发(七)
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2022-09-14 17:33:15
音乐播放器开发MediaPlayer 是Android 控制音频和视频文件播放类1.创建MediaPlayer 对象 的Create方法2.无can构造方法 -> setDataSorce -> prepare()加载创造文件注意访问SDK需要授予权限当Mediaplay.stop() 资源后需要重新加载资源,使用Mediaplay.setDataSource() 方法进行加载 ,最后还需要释放资源,防止内存泄漏缺点: 1.延迟低长,占有资源多 2. 不支持同时播放多个音频p...
音乐播放器开发
MediaPlayer 是Android 控制音频和视频文件播放类
1.创建MediaPlayer 对象 的Create方法
2.无can构造方法 -> setDataSorce -> prepare()加载创造文件注意访问SDK需要授予权限
当Mediaplay.stop() 资源后需要重新加载资源,使用Mediaplay.setDataSource() 方法进行加载 ,最后还需要释放资源,防止内存泄漏
- 缺点: 1.延迟低长,占有资源多 2. 不支持同时播放多个音频
package com.example.myapplication;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageButton;
import android.widget.Toast;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import java.io.File;
import java.io.IOException;
/**
* MediaPlay 实现简易的播放器
*/
public class MainActivity extends AppCompatActivity {
private MediaPlayer mediaPlayer; //定义MediaPlayer对象
private boolean isPause = false; //定义是否暂停
private File file;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ImageButton btn_play = (ImageButton) findViewById(R.id.btn_play); //获取“播放/暂停”按钮
final ImageButton btn_stop = (ImageButton) findViewById(R.id.btn_stop); //获取“停止”按钮
;
file = new File("/res/raw/bird.ogg");
if (file.exists()) {
mediaPlayer = MediaPlayer.create(this, Uri.parse(file.getAbsolutePath()));
} else {
Toast.makeText(MainActivity.this, "要播放的音频文件不存在!", Toast.LENGTH_SHORT).show();
return;
}
// 为MediaPlayer 添加监听事件 完成事件监听器,当media.play.stop 后在重新play
mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mediaPlayer) {
play();
}
});
btn_play.setOnClickListener(new View.OnClickListener(){
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
@Override
public void onClick(View view) {
if(mediaPlayer.isPlaying() && !isPause){
mediaPlayer.pause();
isPause = true; // 暂停播放
// 更好播放图标
((ImageButton) view).setImageDrawable(getResources().getDrawable(R.drawable.play, null));
}else{
mediaPlayer.start(); //继续播放
// 更换为暂停图标
((ImageButton) view).setImageDrawable(getResources().getDrawable(R.drawable.pause, null));
isPause = false; //设置为播放状态
}
}
});
btn_stop.setOnClickListener(new View.OnClickListener() { //单击停止按钮,实现停止播放音频
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
@Override
public void onClick(View v) {
mediaPlayer.stop(); //停止播放
//更换为播放图标
btn_play.setImageDrawable(getResources().getDrawable(R.drawable.play, null));
}
});
}
private void play(){
// 重置MediaPlay
mediaPlayer.reset();
try {
mediaPlayer.setDataSource(file.getAbsolutePath());
mediaPlayer.prepare(); // 预加载
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
protected void onDestroy() {
if(mediaPlayer.isPlaying()){
mediaPlayer.stop();
}
mediaPlayer.release();
super.onDestroy();
}
}
SoundPool 播放多个音频
优点: 1. 延迟低 2.占有资源少 3. 支持多个音频播放
缺点: 不能播放大文件音频
应用场景: 小型游戏中多个飞机被击破声音
创建SoundPool 对象,load , play
package com.example.myapplication;
import android.media.AudioAttributes;
import android.media.SoundPool;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import androidx.appcompat.app.AppCompatActivity;
import java.util.HashMap;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = findViewById(R.id.listView);
// 创建SoundPool 对象设置音频相关特性
//1.音频对象
AudioAttributes attr = new AudioAttributes.Builder() //设置音效相关属性
.setUsage(AudioAttributes.USAGE_GAME) // 设置音效使用场景
.setContentType(AudioAttributes.CONTENT_TYPE_MUSIC) // 设置音效的类型
.build();
final SoundPool soundpool = new SoundPool.Builder() // 创建SoundPool对象
.setAudioAttributes(attr) // 设置音效池的属性
.setMaxStreams(10) // 设置最多可容纳10个音频流,
.build();
// 要播放音频保存到HashMap中
final HashMap<Integer, Integer> soundmap = new HashMap<Integer, Integer>();
soundmap.put(0, soundpool.load(this, R.raw.cuckoo, 1));
soundmap.put(1, soundpool.load(this, R.raw.chimes, 1));
soundmap.put(2, soundpool.load(this, R.raw.notify, 1));
soundmap.put(3, soundpool.load(this, R.raw.ringout, 1));
soundmap.put(4, soundpool.load(this, R.raw.bird, 1));
soundmap.put(5, soundpool.load(this, R.raw.water, 1));
soundmap.put(6, soundpool.load(this, R.raw.cock, 1));
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
soundpool.play(soundmap.get(i),1,1,0,0,1);
}
});
}
}
video View 播放视频
- 在XML中添加Videoview 组件:
<?xml version="1.0" encoding="utf-8"?>
<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="match_parent"
tools:context=".MainActivity">
<VideoView
android:id="@+id/video"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
读取SDK上数据 设置Mainifest.xml 设置访问权限,同时在Android 机器上设置权限打开
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
-----------------------------------------------------------
<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.mingrisoft"
xmlns:android="http://schemas.android.com/apk/res/android">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity" android:screenOrientation="landscape">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
</manifest>
package com.example.myapplication;
import android.media.MediaPlayer;
import android.os.Bundle;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import android.os.Environment;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.MediaController;
import android.widget.Toast;
import android.widget.VideoView;
import java.io.File;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
VideoView videoView = findViewById(R.id.video);
File file = new File(Environment.getExternalStorageDirectory()+"/video.mp4");
if(file.exists()){
videoView.setVideoPath(file.getAbsolutePath());
}else{
return ;
}
// 控制视频播放
MediaController mc = new MediaController(MainActivity.this);
videoView.setMediaController(mc);
// videoiew 获取焦点
videoView.requestFocus();
videoView.start();
// 完成监听器
videoView.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mediaPlayer) {
Toast.makeText(MainActivity.this,"视频播放完成",Toast.LENGTH_SHORT).show();
}
});
}
}
控制摄像头摄像
<!-- 授予程序可以向SD卡中保存文件的权限 -->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<!-- 授予程序使用摄像头的权限 -->
<uses-permission android:name="android.permission.CAMERA"/>
<uses-feature android:name="android.hardware.camera.autofocus"/>
<uses-feature android:name="android.hardware.camera"/>
package com.example.myapplication;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.WindowManager;
import android.widget.ImageButton;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
private Camera camera;
private boolean isPreview = false; // 设置是否是预览状态
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//设置全屏显示
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
if (!android.os.Environment.getExternalStorageState().equals( //判断手机是否安装SD卡
android.os.Environment.MEDIA_MOUNTED)) {
Toast.makeText(this, "请安装SD卡!", Toast.LENGTH_SHORT).show(); // 提示安装SD卡
}
// 设置预览
final SurfaceView surfaceView = findViewById(R.id.surfaceView);
final SurfaceHolder surfaceHolder = surfaceView.getHolder();
// 设置自己维护缓存
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
ImageButton preview = (ImageButton) findViewById(R.id.preview); //获取“预览”按钮
ImageButton takePicture = (ImageButton) findViewById(R.id.takephoto); //获取“拍照”按钮
preview.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (!isPreview) {
camera = Camera.open();
isPreview = true;
}
try {
camera.setPreviewDisplay(surfaceHolder); // 设置用于显示预览的SurfaceView
Camera.Parameters parameters = camera.getParameters(); //获取相机参数
parameters.setPictureFormat(PixelFormat.JPEG); //指定图片为JPEG图片
parameters.set("jpeg-quality", 80); //设置图片的质量
camera.setParameters(parameters); //重新设置相机参数
camera.startPreview(); //开始预览
camera.autoFocus(null); //设置自动对焦
} catch (IOException e) { //输出异常信息
e.printStackTrace();
}
}
});
// 保存拍照
//实现相机拍照功能
takePicture.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (camera != null) { //相机不为空
camera.takePicture(null, null, jpeg); //进行拍照
}
}
});
}
final Camera.PictureCallback jpeg = new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
// 根据拍照所得的数据创建位图
final Bitmap bm = BitmapFactory.decodeByteArray(data, 0,
data.length);
camera.stopPreview(); //停止预览
isPreview = false; //设置为非预览状态
//获取sd卡根目录
File appDir = new File(Environment.getExternalStorageDirectory(), "/DCIM/Camera/");
if (!appDir.exists()) { //如果该目录不存在
appDir.mkdir(); //就创建该目录
}
String fileName = System.currentTimeMillis() + ".jpg"; //将获取当前系统时间设置为照片名称
File file = new File(appDir, fileName); //创建文件对象
try { //保存拍到的图片
FileOutputStream fos = new FileOutputStream(file); //创建一个文件输出流对象
bm.compress(Bitmap.CompressFormat.JPEG, 100, fos); //将图片内容压缩为JPEG格式输出到输出流对象中
fos.flush(); //将缓冲区中的数据全部写出到输出流中
fos.close(); //关闭文件输出流对象
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// 将照片插入到图库当中
try {
MediaStore.Images.Media.insertImage(MainActivity.this.getContentResolver(),
file.getAbsolutePath(),fileName,null);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
// 更新通知图库
MainActivity.this.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.parse("file://" + "")));
restCamera();
}
};
private void restCamera(){
if(!isPreview){
camera.startPreview();
isPreview = true;
}
}
@Override
protected void onPause() { //当暂停Activity时,停止预览并释放资源
if (camera != null) { //如果相机不为空
camera.stopPreview(); //停止预览
camera.release(); //释放资源
}
super.onPause();
}
}
本文地址:https://blog.csdn.net/qq_27217017/article/details/107282553