Java 怎么生成midievent

2019年7月29日20:06:47Java 怎么生成midievent已关闭评论 527 3691字阅读12分18秒

1.简介

Java 怎么生成midievent?——请看下文。

2.示例代码

/**
 * 版权所有 编程十万个怎么办(www.tah1986.com)
 */
import javax.swing.*;
import java.awt.*;
import java.util.ArrayList;
import javax.sound.midi.*;
import java.awt.event.*;

class BeatBoxTest {
    JPanel mainPanel;
    JFrame theFrame;
    ArrayList<JCheckBox> checkboxList;
    String[] instrumentNames = { "Bass Drum", "Closed Hi-Hat",
            "Open Hi-Hat", "Acoustic Snare", "Crash Cymbal", "Hand Clap",
            "High Tom", "Hi Bingo", "Maracas", "Whistle", "Low Conga",
            "Cowbell", "Vibraslap", "Low-mid Tom", "High Agogo",
            "Open Hi Conga" };
    int[] instruments = { 35, 42, 46, 38, 49, 39, 50, 60, 70, 71, 64, 56,
            58, 47, 67, 63 };
    Sequencer sequencer;
    Sequence sequence;
    Track track;

    public static void main(String[] args) {
        new BeatBoxTest().buildGui();
    }

    public void buildGui() {
        theFrame = new JFrame("Cyber Beat Box");
        theFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        BorderLayout layout = new BorderLayout();
        JPanel background = new JPanel(layout);
        background.setBorder(BorderFactory
                .createEmptyBorder(10, 10, 10, 10));

        checkboxList = new ArrayList<JCheckBox>();
        Box buttonBox = new Box(BoxLayout.Y_AXIS);

        JButton start = new JButton("Start");
        JButton stop = new JButton("Stop");
        JButton upTempo = new JButton("Tempo Up");
        JButton downTempo = new JButton("Tempo Down");

        start.addActionListener(new MyStartListener());
        stop.addActionListener(new MyStopListener());
        upTempo.addActionListener(new MyUpTempoListener());
        downTempo.addActionListener(new MyDownTempoListener());

        buttonBox.add(start);
        buttonBox.add(stop);
        buttonBox.add(upTempo);
        buttonBox.add(downTempo);

        background.add(BorderLayout.EAST, buttonBox);

        Box nameBox = new Box(BoxLayout.Y_AXIS);
        for (String str : instrumentNames) {
            nameBox.add(new Label(str));
        }

        background.add(BorderLayout.WEST, nameBox);

        background.setBackground(Color.PINK);
        theFrame.getContentPane().add(background);

        GridLayout grid = new GridLayout(16, 16);
        mainPanel = new JPanel(grid);
        background.add(BorderLayout.CENTER, mainPanel);

        for (int i = 0; i < 256; i++) {
            JCheckBox c = new JCheckBox();
            c.setSelected(false);
            checkboxList.add(c);
            mainPanel.add(c);
        }

        setUpMidi();
        theFrame.setBounds(50, 50, 300, 300);
        theFrame.pack();
        theFrame.setVisible(true);
    }

    public void setUpMidi() {
        try {
            sequencer = MidiSystem.getSequencer();
            sequencer.open();
            sequence = new Sequence(Sequence.PPQ, 4);
            track = sequence.createTrack();
            sequencer.setTempoInBPM(120);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void buildTrackAndStart() {
        int[] trackList = null;
        sequence.deleteTrack(track);
        track = sequence.createTrack();

        for (int i = 0; i < 16; i++) {
            trackList = new int[16];

            int key = instruments[i];

            for (int j = 0; j < 16; j++) {
                JCheckBox jc = (JCheckBox) checkboxList.get(j + (16 * i));
                if (jc.isSelected()) {
                    trackList[j] = key;
                } else {
                    trackList[j] = 0;
                }
            }

            makeTracks(trackList);

            try {
                sequencer.setSequence(sequence);
                sequencer.setLoopCount(sequencer.LOOP_CONTINUOUSLY);
                sequencer.start();
                sequencer.setTempoInBPM(120);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    public void makeTracks(int[] list) {
        for (int i = 0; i < 16; i++) {
            int key = list[i];

            if (key != 0) {
                track.add(makeEvent(144, 2, key, 100, i));
                track.add(makeEvent(128, 2, key, 100, i + 1));
            }
        }
    }

    public MidiEvent makeEvent(int comd, int chan, int one, int two,
            int tick) {
        MidiEvent event = null;
        try {
            ShortMessage a = new ShortMessage();
            a.setMessage(comd, chan, one, two);
            event = new MidiEvent(a, tick);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return event;
    }

    public class MyStartListener implements ActionListener {
        public void actionPerformed(ActionEvent a) {
            buildTrackAndStart();
        }
    }

    public class MyStopListener implements ActionListener {
        public void actionPerformed(ActionEvent a) {
            sequencer.stop();
        }
    }

    public class MyUpTempoListener implements ActionListener {
        public void actionPerformed(ActionEvent a) {
            float tempoFactor = sequencer.getTempoFactor();
            sequencer.setTempoFactor((float) (tempoFactor * 1.03));
        }
    }

    public class MyDownTempoListener implements ActionListener {
        public void actionPerformed(ActionEvent a) {
            float tempoFactor = sequencer.getTempoFactor();
            sequencer.setTempoFactor((float) (tempoFactor * .97));
        }
    }
}

 
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