我在java中创建了一个BarChart使用。jfreechart该条是根据一个月中的天数绘制的。例如这个月 March 包含 31 天，因此将有 31 个 bar 。问题是当我单击下一个按钮时，月份变为包含 30 天的 4 月，即 30 个柱。我们如何BarChart在按钮单击时根据一个月中的天数来更改。
谁能告诉我该怎么做。
user2040500
问问题
2083 次
1 回答
3
您需要更新您dataset的每次更改。我添加了一个updateDataset()方法并在几个关键位置调用它。
private void updateDataset() {
dataset.clear();
for (int i = 1; i <= finalday; i++) {
dataset.setValue(i, "Marks", "" + i);
}
笔记：
不要使用绝对布局；让布局发挥作用。
不要自己做日期算术；使用
Calendar，例如。不要在构造函数中调用可覆盖的方法。
请重构您的代码以限制变量的数量和范围。
请务必使用有意义的名称，尤其是实例变量。
SSCCE，未完全修订：
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ItemEvent;
import java.util.Calendar;
import java.util.GregorianCalendar;
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartFrame;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.BarRenderer;
import org.jfree.data.category.DefaultCategoryDataset;
public class BarGraph {
public int count = 0, count1 = 0, count2 = 0, count3 = 0, count4 = 0;
public int contstatus = 2;
public int date, year, mon, fn, show = 0, finalday, leapcn = 0, task = 0;
String startdte, enddte, monthweek, leavedates = "", nneed = "", year4enab, month4enab, days;
ChartFrame frame;
public static int st = 0;
JButton left = new JButton("<");
JButton right = new JButton(">");
JComboBox month = new JComboBox();
JSpinner yearspin = new javax.swing.JSpinner();
JLabel monthLabel = new javax.swing.JLabel();
JLabel yearLabel = new javax.swing.JLabel();
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
BarGraph() {
task = 1;
Calendar cal;
left.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
left.setRequestFocusEnabled(false);
left.addActionListener(new java.awt.event.ActionListener() {
@Override
public void actionPerformed(java.awt.event.ActionEvent evt) {
leftActionPerformed(evt);
}
});
right.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
right.setRequestFocusEnabled(false);
right.addActionListener(new java.awt.event.ActionListener() {
@Override
public void actionPerformed(java.awt.event.ActionEvent evt) {
rightActionPerformed(evt);
}
});
month.setMaximumRowCount(12);
month.setModel(new javax.swing.DefaultComboBoxModel(new String[]{"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"}));
month.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
month.addItemListener(new java.awt.event.ItemListener() {
@Override
public void itemStateChanged(java.awt.event.ItemEvent evt) {
monthItemStateChanged(evt);
}
});
yearspin.setCursor(new java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
yearspin.setValue(year);
yearspin.addChangeListener(new javax.swing.event.ChangeListener() {
@Override
public void stateChanged(javax.swing.event.ChangeEvent evt) {
yearspinStateChanged(evt);
}
});
monthLabel.setBackground(new java.awt.Color(255, 255, 255));
monthLabel.setFont(new java.awt.Font("Tahoma", 1, 13)); // NOI18N
monthLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
monthLabel.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, null, java.awt.Color.black, null, null));
monthLabel.setOpaque(true);
monthLabel.setText("SEPTEMBER");
yearLabel.setBackground(new java.awt.Color(255, 255, 255));
yearLabel.setFont(new java.awt.Font("Tahoma", 1, 13)); // NOI18N
yearLabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
yearLabel.setBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, null, java.awt.Color.black, null, null));
yearLabel.setOpaque(true);
yearLabel.setText("2013");
cal = new GregorianCalendar();
year = cal.get(Calendar.YEAR);
mon = cal.get(Calendar.MONTH);
date = cal.get(Calendar.DATE);
yearspin.setValue(year);
month.setSelectedIndex(mon);
calendar(year, mon);
month4enab = getMonth(monthLabel.getText());
year4enab = yearLabel.getText();
startdte = year4enab + "-" + month4enab + "-01";
enddte = year4enab + "-" + month4enab + "-" + finalday;
}
public static void main(String[] args) {
new BarGraph().showBar();
}
private void leftActionPerformed(ActionEvent evt) {
show = 0;
if (mon == 0) {
year--;
mon = 11;
} else {
mon--;
}
yearspin.setValue(year);
month.setSelectedIndex(mon);
display();
calendar(year, mon);
displayCalendar();
updateDataset();
}
private void rightActionPerformed(ActionEvent evt) {
show = 0;
if (mon == 11) {
year++;
mon = 0;
} else {
mon++;
}
yearspin.setValue(year);
month.setSelectedIndex(mon);
display();
calendar(year, mon);
displayCalendar();
updateDataset();
}
private void displayCalendar() {
month4enab = getMonth(monthLabel.getText());
year4enab = yearLabel.getText();
startdte = year4enab + "-" + month4enab + "-01";
enddte = year4enab + "-" + month4enab + "-" + finalday;
}
private void monthItemStateChanged(ItemEvent evt) {
show = 0;
String s = (String) month.getSelectedItem();
if ("January".equals(s)) {
mon = 0;
}
if ("February".equals(s)) {
mon = 1;
}
if ("March".equals(s)) {
mon = 2;
}
if ("April".equals(s)) {
mon = 3;
}
if ("May".equals(s)) {
mon = 4;
}
if ("June".equals(s)) {
mon = 5;
}
if ("July".equals(s)) {
mon = 6;
}
if ("August".equals(s)) {
mon = 7;
}
if ("September".equals(s)) {
mon = 8;
}
if ("October".equals(s)) {
mon = 9;
}
if ("November".equals(s)) {
mon = 10;
}
if ("December".equals(s)) {
mon = 11;
}
display();
calendar(year, mon);
updateDataset();
}
private void yearspinStateChanged(ChangeEvent evt) {
show = 0;
year = (Integer) yearspin.getValue();
display();
calendar(year, mon);
updateDataset();
}
public void display() {
String month = "", day = "";
if (mon < 9) {
month = "0" + (mon + 1);
} else {
month = "" + (mon + 1);
}
if (nneed.length() < 2) {
day = "0" + nneed;
} else {
day = "" + nneed;
}
String datss = year + "-" + (month) + "-" + day;
switch (mon) {
case 0:
monthLabel.setText("JANUARY");
break;
case 1:
monthLabel.setText("FEBRUARY");
break;
case 2:
monthLabel.setText("MARCH");
break;
case 3:
monthLabel.setText("APRIL");
break;
case 4:
monthLabel.setText("MAY");
break;
case 5:
monthLabel.setText("JUNE");
break;
case 6:
monthLabel.setText("JULY");
break;
case 7:
monthLabel.setText("AUGUST");
break;
case 8:
monthLabel.setText("SEPTEMBER");
break;
case 9:
monthLabel.setText("OCTOBER");
break;
case 10:
monthLabel.setText("NOVEMBER");
break;
case 11:
monthLabel.setText("DECEMBER");
break;
}
yearLabel.setText(String.valueOf(year));
}
public void calendar(int year, int mon) {
int year1 = year;
int count1 = 1, fun = 0, day, day1 = 0, key = 0, k = -1, s = 1, ck = 2, cheak, y = 0;
day1 = year % 100;
fun = 1 + (day1 / 4);
switch (mon) {
case 0:
key = 1;
k = -1;
break;
case 1:
key = 4;
k = 0;
break;
case 2:
key = 4;
k = 0;
break;
case 3:
key = 0;
k = 0;
break;
case 4:
key = 2;
k = 0;
break;
case 5:
key = 5;
k = 0;
break;
case 6:
key = 0;
k = 0;
break;
case 7:
key = 3;
k = 0;
break;
case 8:
key = 6;
k = 0;
break;
case 9:
key = 1;
k = 0;
break;
case 10:
key = 4;
k = 0;
break;
case 11:
key = 6;
k = 0;
break;
}
if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
k = -1;
day = 29;
leapcn = 0;
if (mon == 0 || mon == 1) {
leapcn = 1;
}
} else {
k = 0;
day = 28;
leapcn = 1;
}
if (year >= 2000) {
y = 6;
}
if (year <= 1900 && year > 2000) {
y = 0;
}
fun = fun + key + k + y;
fun = (fun + day1) % 7;
if (fun == 0) {
fun = 7;
}
if (mon == 0 || mon == 2 || mon == 4 || mon == 6 || mon == 7 || mon == 9 || mon == 11) {
day = 31;
}
if (mon == 3 || mon == 5 || mon == 8 || mon == 10) {
day = 30;
}
finalday = day;
System.out.println("DAYS IN THIS MONTHS:" + finalday);
cheak = fun + 1;
s++;
}
public static String getMonth(String s) {
String mont = "56";
if ("January".equalsIgnoreCase(s)) {
mont = "01";
} else if ("February".equalsIgnoreCase(s)) {
mont = "02";
} else if ("March".equalsIgnoreCase(s)) {
mont = "03";
} else if ("April".equalsIgnoreCase(s)) {
mont = "04";
} else if ("May".equalsIgnoreCase(s)) {
mont = "05";
} else if ("June".equalsIgnoreCase(s)) {
mont = "06";
} else if ("July".equalsIgnoreCase(s)) {
mont = "07";
} else if ("August".equalsIgnoreCase(s)) {
mont = "08";
} else if ("September".equalsIgnoreCase(s)) {
mont = "09";
} else if ("October".equalsIgnoreCase(s)) {
mont = "10";
} else if ("November".equalsIgnoreCase(s)) {
mont = "11";
} else if ("December".equalsIgnoreCase(s)) {
mont = "12";
}
return mont;
}
private void showBar() {
for (int i = 1; i <= finalday; i++) {
dataset.setValue(i, "Marks", "" + i);
}
JFreeChart chart = ChartFactory.createBarChart(" ", "Student", "Marks",
dataset, PlotOrientation.VERTICAL, false, true, false);
chart.setBackgroundPaint(Color.WHITE);
CategoryPlot plot = (CategoryPlot) chart.getPlot();
plot.setBackgroundPaint(new Color(221, 223, 238));
plot.setRangeGridlinePaint(Color.white);
BarRenderer renderer = (BarRenderer) plot.getRenderer();
renderer.setSeriesPaint(0, new Color(231, 175, 61));
renderer.setSeriesPaint(1, Color.green);
renderer.setDrawBarOutline(false);
renderer.setShadowVisible(false);
chart.setBackgroundPaint(Color.WHITE);
chart.getTitle().setPaint(Color.blue);
CategoryPlot p = chart.getCategoryPlot();
p.setRangeGridlinePaint(Color.BLUE);
frame = new ChartFrame("Bar Chart", chart);
frame.add(month);
frame.add(left);
frame.add(right);
frame.add(yearspin);
frame.add(monthLabel);
frame.add(yearLabel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private void updateDataset() {
dataset.clear();
for (int i = 1; i <= finalday; i++) {
dataset.setValue(i, "Marks", "" + i);
}
}
}
于 2013-03-09T13:05:19.533 回答