这是我想在属性编辑器中看到的一个示例，而不是所有大写字母，我只想看到第一个。
package Components;
import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.beans.SimpleBeanInfo;
public class ChartBean2BeanInfo extends SimpleBeanInfo {
public ChartBean2BeanInfo() {
try {
PropertyDescriptor titlePositionDescriptor = new PropertyDescriptor("titlePosition", ChartBean2.class);
titlePositionDescriptor.setPropertyEditorClass(TitlePositionEditor.class);
propertyDescriptors = new PropertyDescriptor[]{new PropertyDescriptor("title", ChartBean2.class),
titlePositionDescriptor, new PropertyDescriptor("graphColor", ChartBean2.class)};
} catch (IntrospectionException e) {
e.printStackTrace();
}
}
public PropertyDescriptor[] getPropertyDescriptors() {
System.out.println(propertyDescriptors);
return propertyDescriptors;
}
PropertyDescriptor[] propertyDescriptors;
}
它执行第 10 行但忽略 11 并连接其标准属性编辑器，如果根本没有，则不显示该属性。
package Components;
import javax.swing.*;
import java.beans.PropertyEditorSupport;
import java.util.Arrays;
public class TitlePositionEditor extends PropertyEditorSupport {
public String[] getTags() {
return tags;
}
public TitlePositionEditor() {
super();
new JFrame().setVisible(true);
}
public String getJavaInitializationString() {
return ChartBean2.Position.class.getName().replace('$', '.') + "." + getValue();
}
public String getAsText() {
int index = ((ChartBean2.Position) getValue()).ordinal();
return tags[index];
}
public void setAsText(String s) {
int index = Arrays.asList(tags).indexOf(s);
if (index >= 0) setValue(ChartBean2.Position.values()[index]);
}
private String[] tags = {"L", "C", "R"};
}
package Components;
import java.awt.*;
import java.awt.font.*;
import java.awt.geom.*;
import javax.swing.*;
/**
* A bean to draw a bar chart.
* @version 1.31 2007-10-03
* @author Cay Horstmann
*/
public class ChartBean2 extends JComponent
{
public ChartBean2()
{
setPreferredSize(new Dimension(XPREFSIZE, YPREFSIZE));
}
public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D) g;
if (values == null || values.length == 0) return;
double minValue = 0;
double maxValue = 0;
for (int i = 0; i < values.length; i++)
{
if (minValue > getValues(i)) minValue = getValues(i);
if (maxValue < getValues(i)) maxValue = getValues(i);
}
if (maxValue == minValue) return;
Rectangle2D bounds = getBounds();
double clientWidth = bounds.getWidth();
double clientHeight = bounds.getHeight();
double barWidth = (clientWidth - 2 * INSETS) / values.length;
g2.setPaint(inverse ? color : Color.white);
g2.fill(new Rectangle2D.Double(0, 0, clientWidth, clientHeight));
g2.setPaint(Color.black);
Font titleFont = new Font("SansSerif", Font.BOLD, 20);
FontRenderContext context = g2.getFontRenderContext();
Rectangle2D titleBounds = titleFont.getStringBounds(title, context);
double titleWidth = titleBounds.getWidth();
double y = -titleBounds.getY();
double x = 0;
if (titlePosition == Position.CENTER) x += (clientWidth - titleWidth) / 2;
else if (titlePosition == Position.RIGHT) x += clientWidth - titleWidth;
g2.setFont(titleFont);
g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
g2.drawString(title, (float) x, (float) y);
double top = titleBounds.getHeight();
double scale = (clientHeight - top - 2 * INSETS) / (maxValue - minValue);
y = clientHeight;
for (int i = 0; i < values.length; i++)
{
double x1 = INSETS + i * barWidth + 1;
double y1 = INSETS + top;
double value = getValues(i);
double height = value * scale;
if (value >= 0) y1 += (maxValue - value) * scale;
else
{
y1 += (int) (maxValue * scale);
height = -height;
}
g2.setPaint(inverse ? Color.white : color);
Rectangle2D bar = new Rectangle2D.Double(x1, y1, barWidth - 2, height);
g2.fill(bar);
g2.setPaint(Color.black);
g2.draw(bar);
}
}
/**
* Sets the title property.
* @param t the new chart title.
*/
public void setTitle(String t)
{
title = t;
}
/**
* Gets the title property.
* @return the chart title.
*/
public String getTitle()
{
return title;
}
/**
* Sets the indexed values property.
* @param v the values to display in the chart.
*/
public void setValues(double[] v)
{
values = v;
}
/**
* Gets the indexed values property.
* @return the values to display in the chart.
*/
public double[] getValues()
{
return values;
}
/**
* Sets the indexed values property.
* @param i the index of the value to set
* @param value the new value for that index
*/
public void setValues(int i, double value)
{
if (0 <= i && i < values.length) values[i] = value;
}
/**
* Gets the indexed values property.
* @param i the index of the value to get
* @return the value for that index
*/
public double getValues(int i)
{
if (0 <= i && i < values.length) return values[i];
return 0;
}
/**
* Sets the inverse property.
* @param b true if the display is inverted (white bars on colored background)
*/
public void setInverse(boolean b)
{
inverse = b;
}
/**
* Gets the inverse property.
* @return true if the display is inverted
*/
public boolean isInverse()
{
return inverse;
}
/**
* Sets the titlePosition property.
* @param p LEFT, CENTER, or RIGHT
*/
public void setTitlePosition(Position p)
{
titlePosition = p;
}
/**
* Gets the titlePosition property.
* @return LEFT, CENTER, or RIGHT
*/
public Position getTitlePosition()
{
return titlePosition;
}
/**
* Sets the graphColor property.
* @param c the color to use for the graph
*/
public void setGraphColor(Color c)
{
color = c;
}
public Color getGraphColor()
{
return color;
}
public enum Position { LEFT, CENTER, RIGHT };
private static final int XPREFSIZE = 300;
private static final int YPREFSIZE = 300;
private static final int INSETS = 10;
private double[] values = { 1, 2, 3 };
private String title = "Title";
private Position titlePosition = Position.CENTER;
private boolean inverse;
private Color color = Color.red;
}