用户界面-Java JTextField不会显示

Question

我正在创建一些GUI，并制作了这个JDialog，试图在其中创建姓名、电话号码和年龄的模板。我的问题是，当你按下按钮时，你会称之为这种方法：

public void createKunde(){
        JDialog addDialog = new JDialog(frame);
        JPanel addContentPane =(JPanel) addDialog.getContentPane();
        addContentPane.setBorder(new EmptyBorder(12,12,12,12));
        addContentPane.setLayout(new BorderLayout(6,6));
        addDialog.setTitle("Opret Kunde");
        addDialog.setSize(800, 400);
        addDialog.setLocationRelativeTo(frame);
        addDialog.setModal(true);
        addDialog.setVisible(true);
        JPanel addContent = new JPanel();
        addContent.setLayout(new GridLayout(4,4));
        JTextField addName = new JTextField(50);
        addContent.add(addName);
        JTextField addAge = new JTextField(50);
        addContent.add(addAge);
        JTextField addPhone = new JTextField(50);
        addContent.add(addPhone);

        addContentPane.add(addContent, BorderLayout.WEST);
        addDialog.add(addContentPane);
    }

我只是无法在我的JDialog中显示TextFields。我看不出问题出在哪里了？

Answer 1

您必须使您的JDialog可见，在末尾添加并从顶部删除：

addDialog.setVisible(true); 

就我记忆中的java swing而言，你不可能让第一个东西可见并构建它

这里有另一个例子：

private void showSimpleDialog() {
    final JDialog d = new JDialog(this, "Run", true);
    d.setSize(200, 150);
    JLabel l = new JLabel("Pagination Swing Demo", JLabel.CENTER);
    d.getContentPane( ).setLayout(new BorderLayout( ));
    d.getContentPane( ).add(l, BorderLayout.CENTER);
    JButton b = new JButton("Run");
    b.addActionListener(new ActionListener( ) {
       public void actionPerformed(ActionEvent ev) {
          createFrame();
          d.setVisible(false);
          d.dispose( );
         }
      });
    JPanel p = new JPanel( );     // Flow layout will center button.
    p.add(b);
    d.getContentPane( ).add(p, BorderLayout.SOUTH);
    d.setLocationRelativeTo(this);
    d.setVisible(true);
}

Answer 2

您的代码正试图将相同的父级添加到容器本身，即jdailog添加到jdsilog本身

并且添加组件后，您的addDialog未设置为可见

所以最好让它在结束时可见

这是您修改后的完整工作程序

package com.kb.gui;
import java.awt.BorderLayout;
import java.awt.Frame;
import java.awt.GridLayout;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
public class JdialogEx1 {
    public static void main(String[] args) {
        createKunde();
    }
    public static void createKunde(){
        Frame frame = new JFrame();
        JDialog addDialog = new JDialog(frame);
        JPanel addContentPane =(JPanel) addDialog.getContentPane();
        addContentPane.setBorder(new EmptyBorder(12,12,12,12));
        addContentPane.setLayout(new BorderLayout(6,6));
        addDialog.setTitle("Opret Kunde");
        addDialog.setSize(800, 400);
        addDialog.setLocationRelativeTo(frame);
        addDialog.setModal(true);

        JPanel addContent = new JPanel();
        addContent.setLayout(new GridLayout(4,4));
        JTextField addName = new JTextField(50);
        addContent.add(addName);
        JTextField addAge = new JTextField(50);
        addContent.add(addAge);
        JTextField addPhone = new JTextField(50);
        addContent.add(addPhone);
       addContentPane.add(addContent, BorderLayout.WEST);
       addDialog.setVisible(true);
    }
}