java窗体编程

Ⅰ 用java编程: 在JFrame窗体中绘制五角星，并用红色填充

importjava.awt.Color;

importjava.awt.Graphics;

importjava.awt.Point;

importjavax.swing.JLabel;

{

=-3847465547528967067L;

privatePointpointA;

privatePointpointB;

privatePointpointC;

privatePointpointD;

privatePointpointE;

privatePointpointLeftInner;

privatePointpointRightInner;

privateintpix;

privatestaticColorbgColor=Color.YELLOW;

privatestaticColorfieldColor=Color.RED;

publicstaticvoidsetBgColor(ColorbgColor){

Pentagram.bgColor=bgColor;

}

publicstaticvoidsetFieldColor(ColorfieldColor){

Pentagram.fieldColor=fieldColor;

}

/**只有width有效，把label弄成正方的*/

publicvoidsetBounds(intx,inty,intwidth,intheight){

super.setBounds(x,y,width,width);

}

/**只有width有效，把label弄成正方的*/

publicvoidsetSize(intwidth,intheight){

super.setSize(width,width);

}

publicvoidsetSize(intsize){

setSize(size,size);

}

publicPentagram(intsize){

pix=size/12;

setSize(pix*12);

initPoints();

}

privatevoidinitPoints(){

pointA=newPoint(6*pix,0);//上边中间点

pointB=newPoint(0,4*pix);//左边上面点

pointC=newPoint(12*pix,4*pix);//右边上面点

pointD=newPoint(3*pix,12*pix);//左边下面点

pointE=newPoint(9*pix,12*pix);//右边下面点

pointLeftInner=newPoint(5*pix,4*pix);//左边里面的点

pointRightInner=newPoint(7*pix,4*pix);//右边里面的点

}

privatevoiddraw(Graphicsg){

fillPolygon(g,pointA,pointLeftInner,pointRightInner);

fillPolygon(g,pointB,pointE,pointRightInner);

fillPolygon(g,pointC,pointD,pointLeftInner);

}

/**

*已知点，填充多边形。

*@paramg画笔

*@parampoints已知的'点'们

*/

privatevoidfillPolygon(Graphicsg,Point...points){

int[]xPoints=newint[points.length];

int[]yPoints=newint[points.length];

for(inti=0;i<points.length;i++){

xPoints[i]=points[i].x;

yPoints[i]=points[i].y;

}

g.fillPolygon(xPoints,yPoints,points.length);

}

publicvoidpaint(Graphicsg){

g.setColor(bgColor);

g.fillRect(0,0,12*pix,12*pix);

g.setColor(fieldColor);

draw(g);

}

}

/**以下是测试代码*/

importjavax.swing.JFrame;

importjavax.swing.JLabel;

publicclassTest{

publicstaticvoidmain(String[]args){

JFrameframe=newJFrame();

frame.setBounds(200,200,400,400);

JLabellabel=newPentagram(frame.getSize().height/2);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.add(label);

frame.setVisible(true);

}

}

Ⅱ java窗口编程中有什么 能精确定位的方法

先设置不使用布局管理器：setLayout(null)。 然后所有控件用setBounds(left, top, width, height)设置绝对定位（left、top）和尺寸（width、height）。 public static void main(String[] args) { JFrame f = new JFrame(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Container c = f.getContentPane(); c.setLayout(null); JButton b = new JButton("button"); b.setBounds(100, 50, 80, 40); c.add(b); f.setSize(400, 300); f.setVisible(true); }

Ⅲ JAVA 编写一个带有窗口的应用程序

这样：

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import java.awt.Graphics;

public class MainClass extends JFrame {

public JComboBox box;

int flag = 0;

jpNewPanel jpNewPanel;

public static void main(String[] args) {

MainClass frame = new MainClass();

frame.setBounds(650,300,550,550);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.setTitle("信号灯");

frame.setVisible(true);

}

public MainClass() {

box = new JComboBox();

box.addItem("请选择");

box.addItem("红灯");

box.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

flag = box.getSelectedIndex();

jpNewPanel.repaint();

}

});

box.addItem("黄灯");

box.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

flag = box.getSelectedIndex();

jpNewPanel.repaint();

}

});

box.addItem("绿灯");

box.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

flag = box.getSelectedIndex();

jpNewPanel.repaint();

}

});

add(box, BorderLayout.NORTH);

jpNewPanel = new jpNewPanel();

add(jpNewPanel, BorderLayout.CENTER);

}

class jpNewPanel extends JPanel {

protected void paintComponent(Graphics g) {

super.paintComponent(g);

g.drawOval(150, 0, 120, 120);

if (flag == 1) {

g.setColor(Color.RED);

g.fillOval(150, 0, 120, 120);

} else if (flag == 2) {

g.setColor(Color.YELLOW);

g.fillOval(150, 0, 120, 120);

} else if (flag == 3) {

g.setColor(Color.GREEN);

g.fillOval(150, 0, 120, 120);

}

}

}

}

(3)java窗体编程扩展阅读：

注意事项

每个Road对象都有一个name成员变量来代表方向，有一个vehicles成员变量来代表方向上的车辆集合。

在Road对象的构造方法中启动一个线程每隔一个随机的时间向vehicles集合中增加一辆车（用一个“路线名_id”形式的字符串进行表示）。

在Road对象的构造方法中启动一个定时器，每隔一秒检查该方向上的灯是否为绿，是则打印车辆集合和将集合中的第一辆车移除掉。