我的DrawPanel有一些问题。我想制作一个烧烤架-应该用参数绘制-由用户通过定义行和冒号给定。
例如，我输入3行和5个冒号（:），Swing应该绘制它。主要问题是，如果我在TextField中输入数字并按下绘制按钮，Swing会在旧网格上绘制新的网格。此外，有时该程序无法完成某些行或冒号，而且我也不明白为什么。我已经添加了一些数字，例如第6行，因为挥杆动作比他应该多画一些像素。也许您也知道该问题的解决方案。
在图片上，您可以看到太多的线条。我用一条蓝线显示线应该走多远。
DrawPanel（JPanel）
import java.awt.Graphics;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author Serge Junk
*/
public class DrawPanel extends javax.swing.JPanel {
/**
* Creates new form DrawPanel
*
*/
private int rows = 1;
private int cols = 2;
public DrawPanel() {
initComponents();
}
@Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
int width = getWidth();
int height = getHeight();
// draw the rows
int rowHt = (height / rows)-1;
for (int i = 0; i <= rows; i++){
g.drawLine(0, i * rowHt, width, i * rowHt);
}
// draw the columns
int rowWid = (width / cols)-1;
for (int i = 0; i <= cols; i++){
g.drawLine(i * rowWid, 0, i * rowWid, height);
}
}
public void setRows(int pRows){
rows = pRows;
}
public void setCols(int pCols){
cols = pCols;
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
setPreferredSize(new java.awt.Dimension(300, 200));
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 300, Short.MAX_VALUE)
);
}// </editor-fold>
// Variables declaration - do not modify
// End of variables declaration
}
大型机（JFrame）
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author Serge Junk
*/
public class MainFrame extends javax.swing.JFrame {
/**
* Creates new form MainFrame
*/
public MainFrame() {
initComponents();
}
public void updateView()
{
drawPanel1.repaint();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
drawPanel1 = new DrawPanel();
jLabel1 = new javax.swing.JLabel();
rowTextField = new javax.swing.JTextField();
jLabel2 = new javax.swing.JLabel();
colsTextField = new javax.swing.JTextField();
drawButton = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
javax.swing.GroupLayout drawPanel1Layout = new javax.swing.GroupLayout(drawPanel1);
drawPanel1.setLayout(drawPanel1Layout);
drawPanel1Layout.setHorizontalGroup(
drawPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 600, Short.MAX_VALUE)
);
drawPanel1Layout.setVerticalGroup(
drawPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 200, Short.MAX_VALUE)
);
jLabel1.setText("Lignes");
jLabel2.setText("Colonnes");
drawButton.setText("Draw");
drawButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
drawButtonActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addGap(18, 18, 18)
.addComponent(rowTextField, javax.swing.GroupLayout.PREFERRED_SIZE, 95, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel2)
.addGap(18, 18, 18)
.addComponent(colsTextField, javax.swing.GroupLayout.PREFERRED_SIZE, 95, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(25, 25, 25)
.addComponent(drawButton))
.addGroup(layout.createSequentialGroup()
.addGap(28, 28, 28)
.addComponent(drawPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, 600, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(26, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(41, 41, 41)
.addComponent(drawPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, 200, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 14, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel1)
.addComponent(rowTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(colsTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(drawButton)))
.addContainerGap())
);
pack();
}// </editor-fold>
private void drawButtonActionPerformed(java.awt.event.ActionEvent evt) {
//E
int row = Integer.valueOf(rowTextField.getText());
int col = Integer.valueOf(colsTextField.getText());
//T
drawPanel1.setRows(row);
drawPanel1.setCols(col);
//S
updateView();
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new MainFrame().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JTextField colsTextField;
private javax.swing.JButton drawButton;
private DrawPanel drawPanel1;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JTextField rowTextField;
// End of variables declaration
}
最佳答案
Netbeans在旧的烤架上绘制了新的烤架。
paintComponent（）方法中的第一条语句应为：
super.paintComponent(g);
在您进行自定义绘画之前，这将清除背景。
drawPanel1.setRows(row);
drawPanel1.setCols(col);
//S
updateView();
不需要
updateView()方法。而是setRows(...)和setCols(...)方法都应直接调用repaint()。这就是组件的责任是在组件的属性更改时重新绘制自身。有时程序无法完成某些行或冒号，而且我也不明白为什么。
int rowHt = height / rows-1;
使用公式时要明确，以便我们确切知道您的意图，而不是依赖编译器。因此，您应该使用：
int rowHt = (height / rows) - 1;
不要害怕为您的参数创建变量：
//g.drawLine(i * rowWid, 0, i * rowWid, height-5);
int xOffset = i * rowWidth;
int yEnd = height - 5;
g.drawLine(xOffset, 0, xOffset, yEnd);
然后，这使您可以轻松添加调试代码，以准确查看用于绘制线条的值：
System.out.println(xOffset + " : " + yEnd);
现在您应该能够确定您的逻辑是否正确。