我已将JButton cl指定为clear，
但是在我的程序中，使用setText("") ...每个文本字段都不JTextField
我不确定它是不是因为我使用了一个数组用于import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class EmployeesApplet extends JApplet implements ActionListener
{
public JButton sd = new JButton ("Salaried");
public JButton hr = new JButton ("Hourly");
public JButton cm = new JButton ("Commissioned");
public JButton cl = new JButton ("Clear");
private final int FIELDS = 8,
FIELD_WIDTH = 20;
private String[] strings = new String[FIELDS];
private TextFieldWithLabel[] tf = new TextFieldWithLabel[FIELDS];
private JTextArea ta = new JTextArea(5,25);
// Add arrays for readFields() method
public void init()
{
String[] s = {"First Name", "Last Name", "Employee ID", "(a) Salaried: Weekly Salary", "(b1) Hourly 1: Rate Per Hour",
"(b2) Hourly 2: Hours Worked" , "(c1) Commissioned: Rate", "(c2) Commissioned: Gross Sales" };
//----------------------
// Set up the Structure
//----------------------
Container c = getContentPane();
JPanel f = new JPanel(new FlowLayout());
JPanel b = new JPanel(new BorderLayout(2,0));
JPanel glb = new JPanel(new GridLayout(8,1,0,2));
JPanel gtf = new JPanel(new GridLayout(8,1,0,2));
JPanel flb = new JPanel(new FlowLayout());
// Add FlowLayout to the container
c.add(f);
// Add BorderLayout to the FlowLayout
f.add(b);
//---------------------------------------
//Add JPanels to the BorderLayout regions
//---------------------------------------
// Add JLables to GridLayout in West
b.add(glb, BorderLayout.WEST);
for (int i = 0; i < tf.length; i++)
{
tf[i] = new TextFieldWithLabel(s[i], FIELD_WIDTH);
glb.add(tf[i].getLabel());
}
// Add JTextFeilds to GridLayout in East
b.add(gtf, BorderLayout.EAST);
for (int i = 0; i < tf.length; i++)
{
tf[i] = new TextFieldWithLabel(s[i], FIELD_WIDTH);
tf[i].getTextField();
gtf.add(tf[i].getTextField());
}
// Add JButtons to FlowLayout in South
b.add(flb, BorderLayout.SOUTH);
flb.add(sd);
flb.add(hr);
flb.add(cm);
flb.add(cl);
sd.addActionListener(this);
hr.addActionListener(this);
cm.addActionListener(this);
cl.addActionListener(this);
// Add JTextArea and make it not editable
f.add(ta);
ta.setEditable(false);
}
//---------------------------------------
// Read all the JTextFields and
// save the contents in a parallel array
//---------------------------------------
private void readFields()
{
for (int i = 0; i < tf.length; i++) // or FIELDS
strings[i] = tf[i].getText();
}
//---------------------------------------------------------------------------
// Returns true if required JTextFields for selected employee are not empty
// Checks required JTextFields in top down order,
// displays error in stats are for first req that is empty and places focus
//----------------------------------------------------------------------------
private boolean fieldsExist(int i, int i2)
{
for (int index = 0; index < tf.length; index++)
{
}
showStatus("field is empty"); // Diplays error message in status area
tf[i].requestFocus(); // places focus in JTextField
return true;
}
//-----------------------------------------------------------------------------------------
// Returns true if all non-required JTextFields for the seleceted employee are empty
// Checks non-required JTextFields in top-down order ,
// displays error message in first non-req JTextField that is not empty and places focus
//-----------------------------------------------------------------------------------------
private boolean fieldsEmpty(int i, int i2)
{
showStatus("field should be empty"); // Diplays error message in status area
tf[i].requestFocus(); // Places focus in JTextField
return true;
}
public void actionPerformed(ActionEvent e)
{
if (e.getSource() == cl)
{
for (int i = 0; i < tf.length; i++)
{
tf[i].setText("");
tf[1].requestFocus();
}
} // End clear if
}
}
或什么......
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;
public class TextFieldWithLabel extends JTextField
{
private JTextField text_field;
private JLabel label;
private final static int WIDTH = 20;
public TextFieldWithLabel (String s, int w)
{
label = new JLabel(s);
text_field = new JTextField(w);
}
public JLabel getLabel() {return label;}
public JTextField getTextField() {return text_field;}
public String getText() {return text_field.getText();}
}
，这是TextFieldWithLabel类
{{1}}
答案 0 :(得分：1)
您想要设置text_field的{{1}}字段的文字，而不是TextFieldWithLabel的文字。
TextFieldWithLabel请注意，您可以删除此tf[i].getTextField().setText("");
tf[1].getTextField().requestFocus();
属性，并直接使用text_field作为TextFieldWithLabel。
更好的是，让JTextField 不扩展TextFieldWithLabel，因为它没有用，它只是两个组件的容器类。