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我是java新手，我似乎无法解决这个问题。我知道我错过了一些东西。

基本上，我正在尝试做的是从 a 中读取用户的输入JTextfield，然后显示用户在另一个中输入的内容JTextfield。

我希望这一切在我点击添加按钮后发生。一旦我点击添加按钮，我希望用户输入从第一个JTextfield然后显示在不同的JTextfield.

但是，当在第一个文本字段中输入内容并点击添加按钮时，我会null在另一个中得到一个值JTextfield。我不知道为什么。

我正在使用应该使用 .gettext() 方法存储用户输入的类变量。

不知道发生了什么任何帮助表示赞赏。

package inventoryprogrampart6;

import javax.swing.JFrame;


public class AddItemWin extends javax.swing.JFrame {
  private int itNm,unitNm,yr;
  private String prodName;
  private double price;
    /**
     * Creates new form AddItemWin
     */
    public AddItemWin() {
        initComponents();
    }

    /**
     * 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() {

        jPanel1 = new javax.swing.JPanel();
        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        jLabel3 = new javax.swing.JLabel();
        jLabel4 = new javax.swing.JLabel();
        jLabel5 = new javax.swing.JLabel();
        textField1 = new java.awt.TextField();
        textField2 = new java.awt.TextField();
        textField3 = new java.awt.TextField();
        textField4 = new java.awt.TextField();
        textField5 = new java.awt.TextField();
        jButton1 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel1.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "Add New Item", javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Times New Roman", 1, 12))); // NOI18N

        jLabel1.setText("Item Number:");

        jLabel2.setText("Product Name:");

        jLabel3.setText("Number of Units:");

        jLabel4.setText("Prodcut Price");

        jLabel5.setText("Year Made:");

        jButton1.setText("Add Item");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addContainerGap()
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jLabel5, javax.swing.GroupLayout.Alignment.TRAILING)
                            .addComponent(jLabel4, javax.swing.GroupLayout.Alignment.TRAILING)
                            .addComponent(jLabel3, javax.swing.GroupLayout.Alignment.TRAILING)
                            .addComponent(jLabel2, javax.swing.GroupLayout.Alignment.TRAILING)
                            .addComponent(jLabel1, javax.swing.GroupLayout.Alignment.TRAILING))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                            .addComponent(textField1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                            .addComponent(textField2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                            .addComponent(textField3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                            .addComponent(textField4, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                            .addComponent(textField5, javax.swing.GroupLayout.DEFAULT_SIZE, 166, Short.MAX_VALUE)))
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(157, 157, 157)
                        .addComponent(jButton1)))
                .addContainerGap(156, Short.MAX_VALUE))
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                                    .addComponent(jLabel1)
                                    .addComponent(textField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                    .addComponent(jLabel2)
                                    .addComponent(textField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(jLabel3))
                            .addComponent(textField3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jLabel4))
                    .addComponent(textField4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(jLabel5)
                    .addComponent(textField5, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(21, 21, 21)
                .addComponent(jButton1)
                .addContainerGap(23, Short.MAX_VALUE))
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(76, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
       textField5.setText(String.valueOf(getitNm())); 


    }                                        

   public void addToArray()
   {
        itNm = Integer.parseInt(textField1.getText());
        prodName = (textField2.getText());
        unitNm = Integer.parseInt(textField3.getText());
        price = Double.parseDouble(textField4.getText());
        yr = Integer.parseInt(textField5.getText());


   }


    public int getitNm()
    {
        return itNm;
    }

    public String getProdName()
    {
        return prodName;
    }
    public int getunitNm()
    {
        return unitNm;
    }
    public double getprice()
    {
        return price;
    }
    public int getyear()
    {
        return yr;
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JPanel jPanel1;
    private java.awt.TextField textField1;
    private java.awt.TextField textField2;
    private java.awt.TextField textField3;
    private java.awt.TextField textField4;
    private java.awt.TextField textField5;
    // End of variables declaration                   
}
4

3 回答 3

0

您没有在课堂上的任何地方调用此方法

 public void addToArray()

这就是您输入的值不会被存储的原因

于 2013-03-15T01:58:17.063 回答
0

首先，您不需要所有额外的代码，它只会浪费内存。实例化类型时取出包名。其次，您不能直接从文本字段中解析某些文本，您必须首先将值放入字符串中。如果这不起作用，请尝试

 myTextBox.setEnabled(true);

如果您需要更多帮助，请询问我。

于 2013-03-15T02:01:51.793 回答
0

有很多问题，主要是围绕着实际上不知道你想要达到的目标的问题......

如果任何字段没有文本（或无法解析为 a 的文本int） ，这将导致错误

public void addToArray() {
    itNm = Integer.parseInt(textField1.getText());
    prodName = (textField2.getText());
    unitNm = Integer.parseInt(textField3.getText());
    price = Double.parseDouble(textField4.getText());
    yr = Integer.parseInt(textField5.getText());
}

这意味着，如果您将最后一个字段留空，它将通过NumberFormatException. 现在，您想要将第一个字段的内容复制到最后一个字段的事实让我更清楚为什么您想要该字段的内容。

在你jButton1ActionPerformed的方法中，你可以简单地使用textField5.setText(textField1.getText())并实现你想要的

于 2013-03-15T03:36:04.107 回答