报错部分代码如下:
public class BeatBox {
JPanel mainPanel;
ArrayList checkboxList;
Sequencer sequencer;
Sequence sequence;
Track track;
JFrame theFrame;
String[] instrumentNames = {"Bass Drum", "Closed Hi-Hat", "Open Hi-Hat", "Acoustic Snare",
"Crash Cymbal", "Hand Clap", "High Tom", "Hi Bongo", "Maracas", "Whistle",
"Low Conga", "Cowbell", "Vibraslap", "Low-mid Tom", "High Agogo", "Open Hi Conga"};
//实际的乐器关键字,例如说35是Bass Drum,42是Closed Hi-Hat
int[] instruments = {35, 42, 46, 38, 49, 39, 50, 60, 70, 72, 64, 56, 58, 47, 67, 63};
public static void main(String[] args) {
new BeatBox().buildGUI();
}
public void buildGUI() {
theFrame = new JFrame("Cyber BeatBox");
theFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
BorderLayout layout = new BorderLayout(); //创建布局对象?
JPanel background = new JPanel(layout);
//设定面板上摆设组件时的空白边缘
background.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
checkboxList = new ArrayList();
Box buttonBox = new Box(BoxLayout.Y_AXIS);
JButton start = new JButton("Start");
start.addActionListener(new MyStartListener());
buttonBox.add(start);
JButton stop = new JButton("Stop");
stop.addActionListener(new MyStopListener());
buttonBox.add(stop);
JButton upTempo = new JButton("Tempo Up");
upTempo.addActionListener(new MyUpTempoListener());
buttonBox.add(upTempo); |