Android實現線上播放音樂
阿新 • • 發佈:2018-12-19
package com.wwj.download;import java.io.File;import java.io.UnsupportedEncodingException;import java.net.URLEncoder;import android.app.Activity;import android.os.Bundle;import android.os.Environment;import android.os.Handler;import android.os.Message;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.ProgressBar;import android.widget.SeekBar;import android.widget.SeekBar.OnSeekBarChangeListener;import android.widget.TextView;import android.widget.Toast;import com.wwj.download.util.Player;import com.wwj.net.download.DownloadProgressListener;import com.wwj.net.download.FileDownloader;public class MainActivity extends Activity { private static final int PROCESSING = 1; private static final int FAILURE = -1; private EditText pathText; // url地址 private TextView resultView; private Button downloadButton; private Button stopButton; private ProgressBar progressBar; private Button playBtn; private Player player; // 播放器 private SeekBar musicProgress; // 音樂進度 private Handler handler = new UIHandler(); private final class UIHandler extends Handler { public void handleMessage(Message msg) { switch (msg.what) { case PROCESSING: // 更新進度 progressBar.setProgress(msg.getData().getInt("size")); float num = (float) progressBar.getProgress() / (float) progressBar.getMax(); int result = (int) (num * 100); // 計算進度 resultView.setText(result + "%"); if (progressBar.getProgress() == progressBar.getMax()) { // 下載完成 Toast.makeText(getApplicationContext(), R.string.success, Toast.LENGTH_LONG).show(); } break; case FAILURE: // 下載失敗 Toast.makeText(getApplicationContext(), R.string.error, Toast.LENGTH_LONG).show(); break; } } } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); pathText = (EditText) findViewById(R.id.path); resultView = (TextView) findViewById(R.id.resultView); downloadButton = (Button) findViewById(R.id.downloadbutton); stopButton = (Button) findViewById(R.id.stopbutton); progressBar = (ProgressBar) findViewById(R.id.progressBar); ButtonClickListener listener = new ButtonClickListener(); downloadButton.setOnClickListener(listener); stopButton.setOnClickListener(listener); playBtn = (Button) findViewById(R.id.btn_online_play); playBtn.setOnClickListener(listener); musicProgress = (SeekBar) findViewById(R.id.music_progress); player = new Player(musicProgress); musicProgress.setOnSeekBarChangeListener(new SeekBarChangeEvent()); } private final class ButtonClickListener implements View.OnClickListener { @Override public void onClick(View v) { switch (v.getId()) { case R.id.downloadbutton: // 開始下載 // http://abv.cn/music/光輝歲月.mp3,可以換成其他檔案下載的連結 String path = pathText.getText().toString(); String filename = path.substring(path.lastIndexOf('/') + 1); try { // URL編碼(這裡是為了將中文進行URL編碼) filename = URLEncoder.encode(filename, "UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } path = path.substring(0, path.lastIndexOf("/") + 1) + filename; if (Environment.getExternalStorageState().equals( Environment.MEDIA_MOUNTED)) { // File savDir = // Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES); // 儲存路徑 File savDir = Environment.getExternalStorageDirectory(); download(path, savDir); } else { Toast.makeText(getApplicationContext(), R.string.sdcarderror, Toast.LENGTH_LONG).show(); } downloadButton.setEnabled(false); stopButton.setEnabled(true); break; case R.id.stopbutton: // 暫停下載 exit(); Toast.makeText(getApplicationContext(), "Now thread is Stopping!!", Toast.LENGTH_LONG).show(); downloadButton.setEnabled(true); stopButton.setEnabled(false); break; case R.id.btn_online_play: new Thread(new Runnable() { @Override public void run() { player.playUrl(pathText.getText().toString()); } }).start(); break; } } /* * 由於使用者的輸入事件(點選button, 觸控式螢幕幕....)是由主執行緒負責處理的,如果主執行緒處於工作狀態, * 此時使用者產生的輸入事件如果沒能在5秒內得到處理,系統就會報“應用無響應”錯誤。 * 所以在主執行緒裡不能執行一件比較耗時的工作,否則會因主執行緒阻塞而無法處理使用者的輸入事件, * 導致“應用無響應”錯誤的出現。耗時的工作應該在子執行緒裡執行。 */ private DownloadTask task; private void exit() { if (task != null) task.exit(); } private void download(String path, File savDir) { task = new DownloadTask(path, savDir); new Thread(task).start(); } /** * * UI控制元件畫面的重繪(更新)是由主執行緒負責處理的,如果在子執行緒中更新UI控制元件的值,更新後的值不會重繪到螢幕上 * 一定要在主執行緒裡更新UI控制元件的值,這樣才能在螢幕上顯示出來,不能在子執行緒中更新UI控制元件的值 * */ private final class DownloadTask implements Runnable { private String path; private File saveDir; private FileDownloader loader; public DownloadTask(String path, File saveDir) { this.path = path; this.saveDir = saveDir; } /** * 退出下載 */ public void exit() { if (loader != null) loader.exit(); } DownloadProgressListener downloadProgressListener = new DownloadProgressListener() { @Override public void onDownloadSize(int size) { Message msg = new Message(); msg.what = PROCESSING; msg.getData().putInt("size", size); handler.sendMessage(msg); } }; public void run() { try { // 例項化一個檔案下載器 loader = new FileDownloader(getApplicationContext(), path, saveDir, 3); // 設定進度條最大值 progressBar.setMax(loader.getFileSize()); loader.download(downloadProgressListener); } catch (Exception e) { e.printStackTrace(); handler.sendMessage(handler.obtainMessage(FAILURE)); // 傳送一條空訊息物件 } } } } // 進度改變 class SeekBarChangeEvent implements OnSeekBarChangeListener { int progress; @Override public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { // 原本是(progress/seekBar.getMax())*player.mediaPlayer.getDuration() this.progress = progress * player.mediaPlayer.getDuration() / seekBar.getMax(); } @Override public void onStartTrackingTouch(SeekBar seekBar) { } @Override public void onStopTrackingTouch(SeekBar seekBar) { // seekTo()的引數是相對與影片時間的數字,而不是與seekBar.getMax()相對的數字 player.mediaPlayer.seekTo(progress); } } @Override protected void onDestroy() { super.onDestroy(); if (player != null) { player.stop(); player = null; } }}