我是 Java GUI 的初学者。我正在编写一个程序来计算给定矩阵的逆矩阵。为此,首先我必须扫描矩阵。我决定用这种方式扫描矩阵:
首先我要问用户方阵的行数或列数。当用户输入一个数字并单击 Tamam
按钮时,我想创建一个小的 NxN JTextField
的。
因此用户将能够轻松输入矩阵的每个元素。我想问的是:我无法创建 NxN JTextField
。我的代码:
private void jButtonRowCntMouseClicked(java.awt.event.MouseEvent evt) {
int i,j;
if(jTextFieldRowCnt.getText() != null){
String cnt = jTextFieldRowCnt.getText();
Integer rowCnt = Integer.parseInt(cnt);
for(i=0;i<rowCnt;i++){
for(j=0;j<rowCnt;j++){
JTextField textField = new JTextField();
this.add(textField);
pack();
}
}
}
}
但是很遗憾,我没能做到。我哪里错了?
我的另一个问题是,如何设置 NxN 个 JTextField
的位置?
最佳答案
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.LineBorder;
public class Test
{
// Field members
static JPanel panel = new JPanel();
static Integer indexer = 1;
static List<JTextField> listOfTextFields = new ArrayList<JTextField>();
public static void main(String[] args)
{
// Construct frame
JFrame frame = new JFrame();
frame.setLayout(new GridBagLayout());
frame.setPreferredSize(new Dimension(990, 990));
frame.setTitle("My Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Frame constraints
GridBagConstraints frameConstraints = new GridBagConstraints();
// Construct button
JButton addButton = new JButton("test");
addButton.addActionListener(new ButtonListener());
// Add button to frame
frameConstraints.gridx = 0;
frameConstraints.gridy = 0;
frame.add(addButton, frameConstraints);
// Construct panel
panel.setPreferredSize(new Dimension(600, 600));
panel.setLayout(new GridBagLayout());
panel.setBorder(LineBorder.createBlackLineBorder());
// Add panel to frame
frameConstraints.gridx = 0;
frameConstraints.gridy = 1;
frameConstraints.weighty = 1;
frame.add(panel, frameConstraints);
// Pack frame
frame.pack();
// Make frame visible
frame.setVisible(true);
}
static class ButtonListener implements ActionListener
{
@Override
public void actionPerformed(ActionEvent arg0)
{
panel.removeAll();
GridBagConstraints textFieldConstraints = new GridBagConstraints();
int rowCnt=4,i,j;
for(i=0;i<rowCnt;i++){
for(j=0;j<rowCnt;j++){
JTextField g=new JTextField();
g.setText("7");
textFieldConstraints.gridx = i;
textFieldConstraints.fill = GridBagConstraints.HORIZONTAL;
textFieldConstraints.weightx = 0.5;
textFieldConstraints.insets = new Insets(10, 10, 10, 10);
textFieldConstraints.gridy = j;
panel.add(g, textFieldConstraints);
}
}
panel.updateUI();
}
}
}
试试这个,得到你想要的
关于java - 在循环中动态创建 JTextField,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/16591305/