英文:
Why setProgress method for JProgressbar is not accepting value over 100?
问题
我正在设计一个进度条，它接收持续时间 [long] 并开始倒计时，直到达到零。因此，我附加了一个代码片段 [test unite] 来模拟该操作。我向任务对象传递了一个值 = 500 [假设为 int]，以在包含程序代码的其余部分之前测试进度条的行为，但不幸的是，除了传递值 = 100 外，它不起作用，我不知道为什么？有人能告诉我在这里漏掉了什么吗？
public class ProgressBarDemo extends JPanel implements ActionListener, PropertyChangeListener {
// ...（省略部分声明和构造函数）
class Task extends SwingWorker<Void, Void> {
int progress;
public Task(int progress) {
super();
this.progress = progress;
}
/*
* 主任务。在后台线程中执行。
*/
@Override
public Void doInBackground() {
// 初始化进度属性。
setProgress(progress);
while (progress > 1) {
// 休眠最多一秒。
try {
Thread.sleep(1000);
} catch (InterruptedException ignore) {
}
// 使进度减少 10。
progress -= 10;
setProgress(progress);
// 如果您想停止计时器
if (progress == 20) {
progress = 100;
}
}
return null;
}
/*
* 在事件分派线程中执行
*/
@Override
public void done() {
Toolkit.getDefaultToolkit().beep();
startButton.setEnabled(true);
setCursor(null); // 关闭等待光标
taskOutput.append("完成！\n");
}
}
// ...（省略部分其他方法和GUI创建代码）
/**
* 当用户按下“开始”按钮时调用。
*/
public void actionPerformed(ActionEvent evt) {
startButton.setEnabled(false);
setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
task = new Task(500);
task.addPropertyChangeListener(this);
task.execute();
}
/**
* 当任务的进度属性更改时调用。
*/
public void propertyChange(PropertyChangeEvent evt) {
if ("progress".equals(evt.getPropertyName())) {
int progress = (Integer) evt.getNewValue();
progressBar.setValue(progress);
taskOutput.append(String.format("已完成任务的 %d%%。\n", task.getProgress()));
}
}
// ...（省略部分其他方法和GUI创建代码）
public static void main(String[] args) {
// 安排一个作业给事件分派线程：
// 创建并显示此应用程序的 GUI。
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
英文:
I am designing a progress bar that taking the duration [long] and start a count down until reaches zero. so I attached a snippet code [test unite] to simulate that action. I passed to the task object a value =500 [let's say as int] to test the behavior of the progress bar before including the rest of the program code but unfortunately, it's not working except passing value =100 and I don't know why? can someone tells me what I missed here?
public class ProgressBarDemo extends JPanel implements ActionListener, PropertyChangeListener {
private JProgressBar progressBar;
private JButton startButton;
private JTextArea taskOutput;
private Task task;
class Task extends SwingWorker<Void, Void> {
int progress;
public Task(int progress) {
super();
this.progress = progress;
}
/*
* Main task. Executed in background thread.
*/
@Override
public Void doInBackground() {
// Initialize progress property.
setProgress(progress);
while (progress > 1) {
// Sleep for up to one second.
try {
Thread.sleep(1000);
} catch (InterruptedException ignore) {
}
// Make progress go down by 10.
progress -= 10;
setProgress(progress);
// if you want to stop the timer
if (progress == 20) {
progress = 100;
}
}
return null;
}
/*
* Executed in event dispatching thread
*/
@Override
public void done() {
Toolkit.getDefaultToolkit().beep();
startButton.setEnabled(true);
setCursor(null); // turn off the wait cursor
taskOutput.append("Done!\n");
}
}
public ProgressBarDemo() {
super(new BorderLayout());
// Create the demo's UI.
startButton = new JButton("Start");
startButton.setActionCommand("start");
startButton.addActionListener(this);
progressBar = new JProgressBar(JProgressBar.HORIZONTAL, 0, 100);
progressBar.setValue(0);
progressBar.setStringPainted(true);
taskOutput = new JTextArea(5, 20);
taskOutput.setMargin(new Insets(5, 5, 5, 5));
taskOutput.setEditable(false);
JPanel panel = new JPanel();
panel.add(startButton);
panel.add(progressBar);
add(panel, BorderLayout.PAGE_START);
add(new JScrollPane(taskOutput), BorderLayout.CENTER);
setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
}
/**
* Invoked when the user presses the start button.
*/
public void actionPerformed(ActionEvent evt) {
startButton.setEnabled(false);
setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
task = new Task(500);
task.addPropertyChangeListener(this);
task.execute();
}
/**
* Invoked when task's progress property changes.
*/
public void propertyChange(PropertyChangeEvent evt) {
if ("progress" == evt.getPropertyName()) {
int progress = (Integer) evt.getNewValue();
progressBar.setValue(progress);
taskOutput.append(String.format("Completed %d%% of task.\n", task.getProgress()));
}
}
/**
* Create the GUI and show it. As with all GUI code, this must run on the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
// Create and set up the window.
JFrame frame = new JFrame("ProgressBarDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Create and set up the content pane.
JComponent newContentPane = new ProgressBarDemo();
newContentPane.setOpaque(true); // content panes must be opaque
frame.setContentPane(newContentPane);
// Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
// Schedule a job for the event-dispatching thread:
// creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
答案1
得分: 1
你已经使用以下代码行初始化了 JProgressBar：
progressBar = new JProgressBar(JProgressBar.HORIZONTAL, 0, 100);
因此，你使用了以下构造函数并将最大值设置为 100：
public JProgressBar(int orient, int min, int max)
英文:
You have initialised the JProgressBar with the following line:
progressBar = new JProgressBar(JProgressBar.HORIZONTAL, 0, 100);
Thus you use the following constructor and set the maximum value to 100:
public JProgressBar(int orient, int min, int max)
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