「java画板程序」javafx实现画板
本篇文章给大家谈谈java画板程序，以及javafx实现画板对应的知识点，希望对各位有所帮助，不要忘了收藏本站喔。
本文目录一览：
java画板不显示
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Painter extends JFrame
{
private int xValue=0,yValue=0;
public Painter()
{
super("A Simple paint program");
getContentPane().add(new JLabel("Drag the Mouse To Paint"),"South");
/*addMouseMotionListener(
new MouseMotionAdapter(){
public void mouseDragged(MouseEvent e)
{
xValue=e.getX();
yValue=e.getY();
repaint();
}
}
);*/
setSize(300,300);
setVisible(true);
}
/*
public void paint(Graphics g)
{
g.fillOval(xValue,yValue,4,4);
}*/
public static void main(String[] args)
{
Painter frame=new Painter();
}
}
这主要是paint(Griphics g)方法的问题
注意java.awt包和javax.swing包中的类的层次问题
java.lang.Object -java.awt.Component -java.awt.Label
java.lang.Object
- java.awt.Component
- java.awt.Container
- javax.swing.JComponent
- javax.swing.JLabel
而在java.awt.Component和javax.swing.JComponent都分别根据组件的清重量级定义了不同实现方式的paint方法
在你的程序中，你是在JFrame中直接进行绘画，而JFrame属于重量级组件，Label属于偏重量级JLabel属于偏轻（轻重的区别就是是否跟本地系统有太大关系）。。JFrame JWindow JDialog 等等。。并且你绘画的区域和你添加Label
的位置有重叠。。。诸多原因导致了无法显示
建议：将绘画的组件 改成JPanel。。可以多分级绘画，也可以并列多个JPanel，然后分别添加 组件 和绘画，不会重叠。。
java画板程序
package draw;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
//the point
//impress the info of one point,the x and y
class OnePoint implements Serializable
{
int x;
int y;
int tool;
Color c;
int border;
public OnePoint(int x,int y,int tool,Color cc,int border)
{
this.x=x;
this.y=y;
this.tool=tool;
this.c=cc;
this.border=border;
}
public static void main(String[] args)
{
DrawingBoard oneBorder=new DrawingBoard();
}
}
class DrawingBoard extends Frame implements MouseListener,ItemListener,ActionListener,MouseMotionListener
{
Button pen,line,ellipse,rect,clear,colorboard,storebutton,openbutton;
Choice sizechoice,colorchoice ;
Label pensize, pencolor;
Panel panel ;
FileDialog storefile, openfile;
FileInputStream filein;
FileOutputStream fileout;
ObjectInputStream objectin;
ObjectOutputStream objectout;
int mode=0;
int flagtool=0;
Color flagcolor;
int border;
BasicStroke size;
private Point2D[] p=new Point2D[3];;
OnePoint p1,p2;
VectorOnePoint points=new VectorOnePoint();
public DrawingBoard()
{
pen=new Button("画笔");
line=new Button("直线");
ellipse=new Button("圆");
rect=new Button("矩形");
clear=new Button("清除");
colorboard=new Button("调色板");
storebutton=new Button("存储文件");
openbutton=new Button("打开文件");
pensize=new Label("画笔大小");
pencolor=new Label("画笔颜色");
storefile=new FileDialog(this,"存储文件",FileDialog.SAVE);
storefile.setVisible(false);
storefile.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
storefile.setVisible(false);
}
});
openfile=new FileDialog(this,"打开文件",FileDialog.LOAD);
openfile.setVisible(false);
openfile.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
openfile.setVisible(false);
}
});
sizechoice=new Choice();
sizechoice.add("1");
sizechoice.add("2");
sizechoice.add("4");
sizechoice.add("6");
sizechoice.add("8");
sizechoice.addItemListener(this);
colorchoice=new Choice();
colorchoice.add("black");
colorchoice.add("red");
colorchoice.add("blue");
colorchoice.add("green");
colorchoice.addItemListener(this);
pen.addActionListener(this);
line.addActionListener(this);
ellipse.addActionListener(this);
rect.addActionListener(this);
clear.addActionListener(this);
colorboard.addActionListener(this);
storebutton.addActionListener(this);
openbutton.addActionListener(this);
panel=new Panel();
panel.add(storebutton);
panel.add(openbutton);
panel.add(pen);
panel.add(line);
panel.add(ellipse);
panel.add(rect);
panel.add(clear);
panel.add(sizechoice);
panel.add(pensize);
panel.add(colorchoice);
panel.add(pencolor);
panel.add(colorboard);
add(panel,BorderLayout.NORTH);
setBounds(100,100,700,600);
setVisible(true);
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
/**
* 添加鼠标事件的监听器，否则，鼠标的移动和点击都将无法识别！
* */
addMouseListener(this);
addMouseMotionListener(this);
}
public void paint(Graphics g)
{
Graphics2D g2d=(Graphics2D)g;
if(flagtool==2)
{ //qing chu
g.clearRect(0,0,getSize().width,getSize().height);
}
for(int i=0;ipoints.size()-1;i++)
{
p1=(OnePoint)points.elementAt(i);
p2=(OnePoint)points.elementAt(i+1);
g2d.setColor(p1.c); //////////////需要使用Graphics2D从Graphics类中继承下来的方法 setColor（）设置当前的颜色
size=new BasicStroke(p1.border,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);
g2d.setStroke(size);
if(p1.tool==p2.tool)
{
switch(p1.tool)
{
case 0:
Line2D.Double line1=new Line2D.Double(p1.x,p1.y,p2.x,p2.y);
g2d.draw(line1);
break;
case 1:
Line2D.Double line2=new Line2D.Double(p1.x,p1.y,p2.x,p2.y);
g2d.draw(line2);
break;
case 3:
Ellipse2D.Double ellipse=new Ellipse2D.Double(p1.x,p1.y,Math.abs(p2.x-p1.x),Math.abs(p2.y-p1.y));
g2d.draw(ellipse);
break;
case 4:
Rectangle2D.Double rect=new Rectangle2D.Double(p1.x,p1.y,Math.abs(p2.x-p1.x),Math.abs(p2.y-p1.y));
g2d.draw(rect);
break;
default:
}
}
}
}
public void mouseClicked(MouseEvent e) {}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) //鼠标点下时候，将当前的点信息记录
{
mode=0;
p[0]=e.getPoint();
OnePoint pp1=new OnePoint(e.getX(),e.getY(),flagtool,flagcolor,border);
points.addElement(pp1);
//repaint();
}
public void mouseReleased(MouseEvent e) //鼠标松开时候，如果是画笔，则当前截断，是其余状态记下一枚点信息
{
mode=1;
if(flagtool==0)
{
points.addElement(new OnePoint(-1,-1,22,flagcolor,border));
}
else
{
OnePoint pp2=new OnePoint(e.getX(),e.getY(),flagtool,flagcolor,border);
points.addElement(pp2);
points.add(new OnePoint(-1,-1,22,flagcolor,border));
}
repaint();
}
public void itemStateChanged(ItemEvent e)
{
if(e.getSource()==colorchoice)
{
String selected=colorchoice.getSelectedItem();
if(selected=="black"){flagcolor=new Color(0,0,0); }
else if(selected=="red"){flagcolor=new Color(255,0,0); }
else if(selected=="blue"){ flagcolor=new Color(0,0,255);}
else if(selected=="green"){ flagcolor=new Color(0,255,0); }
}
else if(e.getSource()==sizechoice)
{
String selected=sizechoice.getSelectedItem();
if (selected=="1"){ border=1; }
else if(selected=="2"){ border=2*2; }
else if(selected=="4"){ border=4*2; }
else if(selected=="6"){ border=6*2; }
else if(selected=="8"){ border=8*2; }
}
}
/*public void update(Graphics g) { //@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
paint(g);
} */
public void actionPerformed(ActionEvent e)
{
// TODO Auto-generated method stub
if(e.getSource()==pen){flagtool=0; }
else if(e.getSource()==line){ flagtool=1; }
else if(e.getSource()==clear)
{
flagtool=2;
points.removeAllElements();
repaint(); //此语要有，否则今生无法删除！
}
else if(e.getSource()==ellipse){ flagtool=3; }
else if(e.getSource()==rect){ flagtool=4; }
else if(e.getSource()==colorboard)
{
/*
* 使用 javax.swing.×包中的 JColorChooser 类的静态方法showDialog（Component component，String title，Color color ），
* 该方法的参数，component是当前显示对话框的父框架，color是设置调色板初始的被选颜色
*
* 该方法返回被选的颜色，类型为Color
* */
Color color=JColorChooser.showDialog(this, "调色板",flagcolor);
flagcolor=color;
}
else if(e.getSource()==openbutton)
{
openfile.setVisible(true);
if(openfile.getFile()!=null)
{
int temp=flagtool;
flagtool=2;
repaint();
try{
points.removeAllElements();
File file=new File(openfile.getDirectory(),openfile.getFile());
filein=new FileInputStream(file);
objectin=new ObjectInputStream(filein);
points=(Vector)objectin.readObject();
objectin.close();
filein.close();
flagtool=temp;
repaint();
}
catch(Exception ee){ System.out.println(ee.toString()); }
}
}
else if(e.getSource()==storebutton)
{
storefile.setVisible(true);
if(storefile.getFile()!=null)
{
try {
File file=new File(storefile.getDirectory(),storefile.getFile());
fileout=new FileOutputStream(file);
objectout=new ObjectOutputStream(fileout);
objectout.writeObject(points);
objectout.close();
fileout.close();
repaint();
}
catch (FileNotFoundException e1)
{
System.out.println(e1.toString());
e1.printStackTrace();
} catch (IOException ee) {
System.out.println(ee.toString());
ee.printStackTrace();
}
}
}
}
public void mouseDragged(MouseEvent e) //鼠标拖动时候，//当且仅当 flagtool＝＝0，或者表示为橡皮的时候
//才将拖动过程中涉及到的点全部记录下来，并且调用repain()方法，重画当前
// TODO Auto-generated method stub
{
if(flagtool==0)
{
OnePoint pp3=new OnePoint(e.getX(),e.getY(),flagtool,flagcolor,border);
points.addElement(pp3);
repaint();
}
if(flagtool==1)
{
OnePoint pp3=new OnePoint(e.getX(),e.getY(),flagtool,flagcolor,border);
repaint();
}
}
public void mouseMoved(MouseEvent e) {
// TODO Auto-generated method stub
}
}
java 涂鸦画板
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Label;
import java.awt.Panel;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class MouseDrawPanel extends Frame
{
private static final long serialVersionUID = 1L;
MouseEvent e = null;
int startX = -1;
int startY = -1;
int endX = -1;
int endY = -1;
boolean left = false;
public MouseDrawPanel ( String title )
{
setTitle (title);
setLayout (new BorderLayout ());
setResizable (false);
setSize (500, 400);
setLocationRelativeTo (null);
addWindowListener (new WindowAdapter ()
{
@Override
public void windowClosing ( WindowEvent e )
{
System.exit (0);
}
});
}
@Override
public void paintComponents ( Graphics g )
{
float lineWidth = 8.0f;
( (Graphics2D) g ).setStroke (new BasicStroke (lineWidth));
g.setColor (Color.YELLOW);
g.drawLine (startX, startY, endX, endY);
g.dispose ();
}
public static void main ( String[] args )
{
final MouseDrawPanel mdp = new MouseDrawPanel ("Use Mouse Draw");
Panel panel = new Panel ();
panel.setLayout (new FlowLayout (FlowLayout.LEFT));
Label startL = new Label ("start: ");
Label endL = new Label ("end: ");
final Label nowL = new Label ("now: ");
final Label startR = new Label ("000,000");
final Label endR = new Label ("000,000");
final Label nowN = new Label ("000,000");
panel.add (startL);
panel.add (startR);
panel.add (endL);
panel.add (endR);
panel.add (nowL);
panel.add (nowN);
mdp.add (panel, "South");
mdp.addMouseMotionListener (new MouseMotionListener ()
{
@Override
public void mouseMoved ( MouseEvent e )
{
if (mdp.left)
{
nowN.setText (e.getX () + " , " + e.getY ());
}
}
@Override
public void mouseDragged ( MouseEvent e )
{
if (mdp.left)
{
mdp.endX = e.getX ();
mdp.endY = e.getY ();
mdp.paintComponents (mdp.getGraphics ());
mdp.startX = mdp.endX;
mdp.startY = mdp.endY;
endR.setText (mdp.endX + " , " + mdp.endY);
}
}
});
mdp.addMouseListener (new MouseAdapter ()
{
@Override
public void mousePressed ( MouseEvent e )
{
if (e.getButton () == MouseEvent.BUTTON1)
{
mdp.startX = e.getX ();
mdp.startY = e.getY ();
startR.setText (mdp.startX + " , " + mdp.startY);
mdp.left = true;
}
else
{
mdp.left = false;
}
}
@Override
public void mouseReleased ( MouseEvent e )
{
if (mdp.left)
{
endR.setText (e.getX () + " , " + e.getY ());
}
}
});
mdp.setVisible (true);
}
}
我想用java编写一个程序，就是能在画板上实现填加一段字符串，最好能提供代码
import java.awt.*;
/**
* @author Hardneedl
*/
interface Brush {
void doPaint(Graphics g);
}
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
/**
* @author Hardneedl
*/
final class StringPaintDemo extends JFrame {
public String getTitle() {return "String Paint";}
static private final Dimension size = new Dimension(600, 400);
public Dimension getPreferredSize() {return size;}
public Dimension getMaximumSize() {return size;}
public Dimension getMinimumSize() {return size;}
public Dimension getSize() {return size;}
private String s;
private Brush stringBrush = new Brush() {
public void doPaint(Graphics g) {
Graphics gg = g.create();
gg.setColor(Color.RED);
gg.drawString(s == null ? "null" : s , 58, 58);
gg.dispose();
}
};
private JTextField txtField;
private JComponent canvas = new JComponent(){
protected void paintComponent(Graphics g) {
super.paintComponent(g);
stringBrush.doPaint(g);
}
};
private StringPaintDemo() throws HeadlessException {
init();
attachListeners();
doLay();
}
private void init() {
txtField = new JTextField();
}
private void attachListeners() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
txtField.getDocument().addDocumentListener(new DocumentListener(){
private void update(){
s = txtField.getText();
canvas.paintImmediately(canvas.getBounds());
}
public void changedUpdate(DocumentEvent e) {update();}
public void insertUpdate(DocumentEvent e) {update();}
public void removeUpdate(DocumentEvent e) {update();}
});
}
private void doLay() {
Container container = getContentPane();
container.add(txtField,BorderLayout.NORTH);
container.add(canvas, BorderLayout.CENTER);
pack();
setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new StringPaintDemo();
}
});
}
}
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发布于：2022-12-02，除非注明，否则均为原创文章，转载请注明出处。