我的程序有2个Frames。 1 Frame包含一个简单的Button和JComboBox GUI界面，而另一个Frame应根据界面上选择的选项绘制和操作形状。
我设置了界面，但我无法弄清楚如何实现多边形绘图。我知道如何绘制多边形，但我在网上搜索的所有教程和帮助并没有真正为我提供绘图+多种方法的组合。另外，我的代码可能对我构建程序的所有尝试都非常复杂，所以我想知道是否可能会增加我的问题。
我将在下面发布我的代码并在我需要关注的地方写下“需要帮助1”和“需要帮助2”。这是我的程序粗略看起来的image。
感谢任何提前尝试对我的问题进行抨击的人。
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.Polygon;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Final {
// Declare variables for everything used in the program
private JFrame f;
private JPanel p, p2;
private JButton b1, b2, b3, b4, b5, b6, b7, b8;
private JComboBox combo, combo2, combo3;
private JTextField txt, txt2, txt3;
private Graphics g;
private Shape selectedShape;
public Final() {
gui();
draw();
}
public void gui() {
f = new JFrame("Interface");
f.setVisible(true);
f.setSize(800, 600);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // Closes the program
// when you click
// the X
p = new JPanel(new GridBagLayout()); // create panel and decide the
// details
p.setBackground(Color.WHITE);
GridBagConstraints c = new GridBagConstraints(); // Define way to call
// constraints for
// grid layout
GridBagConstraints c2 = new GridBagConstraints();
GridBagConstraints c3 = new GridBagConstraints();
c.insets = new Insets(0, 0, 0, 0); // add spacing between objects on the
// grid. 10 pixels from bottom top,
// left and right
c2.insets = new Insets(5, 5, 5, 5);
c3.insets = new Insets(0, 0, 0, 0);
// Combo Box stuff below this
String course2[] = { "CHOOSE", "YELLOW", "BLUE", "RED" };
String course3[] = { "CHOOSE", "YELLOW", "BLUE", "RED" };
combo = new JComboBox(Shape.values());
combo.setBackground(Color.white);
combo.setForeground(Color.black);
txt = new JTextField(20);
combo.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent ie) {
if(ie.getStateChange() == ItemEvent.DESELECTED) {
return;
}
Shape selectedShape = (Shape) combo.getSelectedItem();
setSelectedShape(selectedShape);
String str = selectedShape.getLabel();
txt.setText(str);
switch (selectedShape) {
case NONE:
break;
case PARALLELOGRAM:
drawParallelogram();
break;
case QUADRILATERAL:
drawQuadrilateral();
break;
case RECTANGLE:
drawRectangle();
break;
case RHOMBUS:
drawRhombus();
break;
case SQUARE:
drawSquare();
break;
case TRAPEZOID:
drawTrapezoid();
break;
case TRIANGLE:
drawTriangle();
break;
default:
break;
}
}
private Polygon drawTriangle() {
// Need Help Here 1
Polygon triangle = new Polygon();
triangle.addPoint(100,100);
triangle.addPoint(150,150);
triangle.addPoint(50,150);
return triangle;
}
private void drawTrapezoid() {
// TODO Auto-generated method stub
System.out.println("This is the code to draw a trapezoid");
}
private void drawSquare() {
// TODO Auto-generated method stub
g.drawRect(0, 0, 50, 50);
}
private void drawRhombus() {
// TODO Auto-generated method stub
}
private void drawRectangle() {
// TODO Auto-generated method stub
System.out.println("This is the code to draw a rectangle");
}
private void drawQuadrilateral() {
// TODO Auto-generated method stub
System.out.println("This is the code to draw a quadrilateral");
}
private void drawParallelogram() {
// TODO Auto-generated method stub
System.out.println("This is the code to draw a parallelogram");
}
});
combo2 = new JComboBox(course2);
combo2.setBackground(Color.white);
combo2.setForeground(Color.black);
txt2 = new JTextField(20);
combo2.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent ie) {
String str2 = (String) combo2.getSelectedItem();
txt2.setText(str2 + " BORDER");
}
});
combo3 = new JComboBox(course3);
combo3.setBackground(Color.white);
combo3.setForeground(Color.black);
txt3 = new JTextField(20);
combo3.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent ie) {
String str3 = (String) combo3.getSelectedItem();
txt3.setText(str3 + " INSIDE");
}
});
// X and Y movement buttons
b1 = new JButton("X+");
b2 = new JButton("X-");
b3 = new JButton("Y+");
b4 = new JButton("Y-");
b5 = new JButton("Clockwise");
b6 = new JButton(" Counter ");
b7 = new JButton("Enlarge");
b8 = new JButton("Shrink ");
// Object adding to panel and grid layout here
c.gridx = 0;
c.gridy = 0;
p.add(combo, c);
c.gridx = 1;
c.gridy = 0;
p.add(txt, c);
c2.gridx = 0; // x and y for first object
c2.gridy = 1;
p.add(b1, c2);
c2.gridx = 1;
c2.gridy = 1;
p.add(b2, c2);
c2.gridx = 0;
c2.gridy = 2;
p.add(b3, c2);
c2.gridx = 1;
c2.gridy = 2;
p.add(b4, c2);
c3.gridx = 0;
c3.gridy = 4;
p.add(combo2, c3);
c3.gridx = 1;
c3.gridy = 4;
p.add(txt2, c3);
c3.gridx = 0;
c3.gridy = 5;
p.add(combo3, c3);
c3.gridx = 1;
c3.gridy = 5;
p.add(txt3, c3);
c2.gridx = 0;
c2.gridy = 6;
p.add(b5, c2);
c2.gridx = 1;
c2.gridy = 6;
p.add(b6, c2);
c2.gridx = 0;
c2.gridy = 7;
p.add(b7, c2);
c2.gridx = 1;
c2.gridy = 7;
p.add(b8, c2);
f.add(p, BorderLayout.NORTH); // add the entire panel to the frame
f.show();
}
public void draw() {
// Need help here 2
// Create a frame
JFrame frame = new JFrame();
// Add a component with a custom paint method
//frame.getContentPane().add(new MyComponent());
Container contentPane = frame.getContentPane();
contentPane.add(drawTriangle());
// Display the frame
int frameWidth = 600;
int frameHeight = 600;
frame.setSize(frameWidth, frameHeight);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
/* class MyComponent extends JComponent {
// This method is called whenever the contents needs to be painted
public void paint(Graphics g) {
// Retrieve the graphics context; this object is used to paint
// shapes
Graphics2D g2d = (Graphics2D) g;
}
}*/
public static void main(String[] args) {
new Final();
}
public Shape getSelectedShape() {
return selectedShape;
}
public void setSelectedShape(Shape selectedShape) {
this.selectedShape = selectedShape;
}
public enum Shape {
NONE, TRIANGLE, QUADRILATERAL, PARALLELOGRAM, TRAPEZOID, RHOMBUS, RECTANGLE, SQUARE;
static {
NONE.label = "Choose one...";
TRIANGLE.label = "Triangle";
QUADRILATERAL.label = "Quadrillateral";
PARALLELOGRAM.label = "Parallelogram";
TRAPEZOID.label = "Trapezoid";
RHOMBUS.label = "Rhombus";
RECTANGLE.label = "Rectangle";
SQUARE.label = "Square";
}
private String label;
public String getLabel() {
return label;
}
}
}
很抱歉这个烂摊子，JComboBoxes似乎是我存在的祸根，我想知道我是否应该只使用JButtons从头开始重建程序。
答案 0 :(得分：3)
而不是形状的枚举（在你的情况下导致非OO开关的情况），我会创建自己的形状类。然后，您可以使用子类（或类型为java.awt.Shape的成员）来实现绘制不同的形状（该示例假定使用java.awt.Shape来描述要传递给构造函数的要绘制的元素）： / p>
public class MyShape {
private String label;
private Shape awtShape;
public MyShape(String label, Shape awtShape) {
this.label = label;
this.awtShape = awtShape;
}
public String toString() {
return label;
}
public int hashCode() {
return label.hashCode();
}
public boolean equals(Object obj) {
return obj instanceof MyShape && ((MyShape) obj).label.equals(label);
}
// x and y parameters may be useful when the shape needs to be relocated
// when drawing. Use Graphics.translate(x, y) to draw the shape at different
// coordinates (don't forget to undo the translater after that).
public void draw(Graphics2D g, int x, int y) {
g.fill(awtShape);
}
}
通过实现toString（），hashCode（）和equals（）方法，您可以将MyShape类用作组合框项（toString（）控制组合框中的显示，hashCode / equals建立标识 - 您可能希望实现它们根据细节要求而有所不同。）