Java 为什么在我最大化窗口后显示JButton和JTextField?
我尝试用Netbeans制作计算器。但是,直到我最大化窗口,计算器的组件才会显示。为什么? 这是源代码:Java 为什么在我最大化窗口后显示JButton和JTextField?,java,swing,user-interface,layout-manager,null-layout-manager,Java,Swing,User Interface,Layout Manager,Null Layout Manager,我尝试用Netbeans制作计算器。但是,直到我最大化窗口,计算器的组件才会显示。为什么? 这是源代码: import java.awt.*; import java.awt.event.*; import javax.swing.*; class Kalkulator extends JFrame implements ActionListener { JTextField tampilan; JLabel label; JButton tom1, tom2, to
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class Kalkulator extends JFrame implements ActionListener {
JTextField tampilan;
JLabel label;
JButton tom1, tom2, tom3, tom4, tom5, tom6, tom7, tom8, tom9, tom0,
tompl, tomkr, tombg, tomkl, tomsd, tomac;
double hasil, bil1, bil2;
String tanda;
public Kalkulator() {
//DESAIN
//FRAME
super("Kalkulator");
this.setSize(350, 350);//mengatur size frame
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//membuat program berhenti ketika close diklik
this.setVisible(true);//membuat GUI jadi tampak
this.getContentPane().setLayout(null);//tidak menggunakan layout apapun, sehingga ukuran konten harus diatur secara manual
//signature
label = new JLabel();
label.setText("Created By NovusZ");//setText untuk mengatur teks dari pada label
label.setBounds(20, 250, 150, 100);//setBounds untuk mengatur posisi dan besar dari objek yang dimaksud
this.getContentPane().add(label);//menambahkan objek yang dimaksud kedalam frame
//LAYAR
//tampilan
tampilan = new JTextField();
tampilan.setBounds(10, 20, 300, 40);
tampilan.setBackground(Color.WHITE);
tampilan.setForeground(Color.BLUE);
this.getContentPane().add(tampilan);
//TOMBOL
//Tombol1
tom1 = new JButton("1");
tom1.setBounds(10, 70, 45, 30);
this.getContentPane().add(tom1);
//Tombol2
tom2 = new JButton("2");
tom2.setBounds(10 + 60, 70, 45, 30);
this.getContentPane().add(tom2);
//Tombol3
tom3 = new JButton("3");
tom3.setBounds(10 + 120, 70, 45, 30);
this.getContentPane().add(tom3);
//Tombol4
tom4 = new JButton("4");
tom4.setBounds(10, 70 + 40, 45, 30);
this.getContentPane().add(tom4);
//Tombol5
tom5 = new JButton("5");
tom5.setBounds(10 + 60, 70 + 40, 45, 30);
this.getContentPane().add(tom5);
//Tombol6
tom6 = new JButton("6");
tom6.setBounds(10 + 120, 70 + 40, 45, 30);
this.getContentPane().add(tom6);
//Tombol7
tom7 = new JButton("7");
tom7.setBounds(10, 70 + 80, 45, 30);
this.getContentPane().add(tom7);
//Tombol8
tom8 = new JButton("8");
tom8.setBounds(10 + 60, 70 + 80, 45, 30);
this.getContentPane().add(tom8);
//Tombol9
tom9 = new JButton("9");
tom9.setBounds(10 + 120, 70 + 80, 45, 30);
this.getContentPane().add(tom9);
//Tombol0
tom0 = new JButton("0");
tom0.setBounds(10, 70 + 120, 165, 30);
this.getContentPane().add(tom0);
//TombolPLUS
tompl = new JButton("plus");
tompl.setBounds(10 + 200, 70, 100, 30);
this.getContentPane().add(tompl);
//Tombolkurang
tomkr = new JButton("Kurang");
tomkr.setBounds(10 + 200, 70 + 40, 100, 30);
this.getContentPane().add(tomkr);
//Tombolbagi
tombg = new JButton("BAGI");
tombg.setBounds(10 + 200, 70 + 80, 100, 30);
this.getContentPane().add(tombg);
//TombolSAMADENGAN
tomkl = new JButton("kali");
tomkl.setBounds(10 + 200, 70 + 120, 100, 30);
this.getContentPane().add(tomkl);
//TombolSAMADENGAN
tomsd = new JButton("(HASIL)");
tomsd.setBounds(10 + 200, 70 + 160, 100, 30);
this.getContentPane().add(tomsd);
//Tombolreset
tomac = new JButton("Reset");
tomac.setBounds(10, 70 + 160, 165, 30);
this.getContentPane().add(tomac);
tom1.addActionListener(this);
tom2.addActionListener(this);
tom3.addActionListener(this);
tom4.addActionListener(this);
tom5.addActionListener(this);
tom6.addActionListener(this);
tom7.addActionListener(this);
tom8.addActionListener(this);
tom9.addActionListener(this);
tom0.addActionListener(this);
tompl.addActionListener(this);
tomkr.addActionListener(this);
tomkl.addActionListener(this);
tomsd.addActionListener(this);
tombg.addActionListener(this);
tomac.addActionListener(this);
}
@Override
public void actionPerformed(ActionEvent e) {
//event
//input
if (e.getSource() == tom1) {
tampil("1");
} else if (e.getSource() == tom2) {
tampil("2");
} else if (e.getSource() == tom3) {
tampil("3");
} else if (e.getSource() == tom4) {
tampil("4");
} else if (e.getSource() == tom5) {
tampil("5");
} else if (e.getSource() == tom6) {
tampil("6");
} else if (e.getSource() == tom7) {
tampil("7");
} else if (e.getSource() == tom8) {
tampil("8");
} else if (e.getSource() == tom9) {
tampil("9");
} else if (e.getSource() == tom0) {
tampil("0");
} //tombol reset
else if (e.getSource() == tomac) {
hasil = 0;
bil1 = 0;
bil2 = 0;
tanda = "";
tampilan.setText("");
tampil("");
} //tombol +
else if (e.getSource() == tompl) {
tanda = "+";//membuat tanda sebagai detektor untuk mengetahui operasi apa yang dipergunakan
bil1 = Double.parseDouble(tampilan.getText());//mengisi nilai bil1 dari nilai yang ada di tampilan
tampilan.setText("");
tampilan.setBackground(Color.YELLOW);
tampilan.setForeground(Color.BLUE);
//tombol -
} else if (e.getSource() == tomkr) {
tanda = "-";
bil1 = Double.parseDouble(tampilan.getText());
tampilan.setText("");
tampilan.setBackground(Color.YELLOW);
tampilan.setForeground(Color.BLUE);
} //tombol X
else if (e.getSource() == tomkl) {
tanda = "x";
bil1 = Double.parseDouble(tampilan.getText());
tampilan.setText("");
} //tombol bagi
else if (e.getSource() == tombg) {
tanda = "/";
bil1 = Double.parseDouble(tampilan.getText());
tampilan.setText("");
tampilan.setBackground(Color.YELLOW);
tampilan.setForeground(Color.BLUE);
} else if (e.getSource() == tomsd) {
bil2 = Double.parseDouble(tampilan.getText());//mengisi nilai bil2 dengan nilai yang ada pada tampilan setelah tombol tanda operasi ditekan
tampilan.setBackground(Color.WHITE);
tampilan.setForeground(Color.BLUE);
//operasi perhitungan
//operasi penjumlahan
if (tanda.equals("+")) {
hasil = bil1 + bil2;
tampilan.setText("" + hasil);
tampilan.setForeground(Color.YELLOW);
tampilan.setBackground(Color.BLUE);
}//operasi pengurangan
else if (tanda.equals("-")) {
hasil = bil1 - bil2;
tampilan.setText("" + hasil);
tampilan.setForeground(Color.YELLOW);
tampilan.setBackground(Color.BLUE);
}//operasi perkalian
else if (tanda.equals("x")) {
hasil = bil1 * bil2;
tampilan.setText("" + hasil);
tampilan.setForeground(Color.YELLOW);
tampilan.setBackground(Color.BLUE);
}//operasi pembagian
else if (tanda.equals("/")) {
hasil = bil1 / bil2;
tampilan.setText("" + hasil);
tampilan.setForeground(Color.YELLOW);
tampilan.setBackground(Color.BLUE);
}
}
}
public static void main(String[] args) {
Kalkulator x = new Kalkulator();
}
public void tampil(String teks) {//membuat method utk menampilkan apa yang telah ditekan pada tombol
tampilan.setText(tampilan.getText() + teks);//set tulisan pada label tampilan. yang diisikan adalah teks yang sudah ditetapkan pada masing-masing tombol dan teks sebelumnya yang sudah ditekan
}
}
作为参考,这就是GUI的外观
如对现已删除的答案的评论中所述,组件未显示的原因是,在添加组件之前,GUI已设置为可见,如果没有导致框架正确布局的后续调用,组件将不会显示 这里是所需GUI的粗略复制。阅读评论中的提示。根据需要调整
int p
以获得更多或更少的空间
import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class Kalkulator {
public Component getGUI() {
// layout padding
int p = 10;
// the GUI as seen by the user (without frame)
JPanel gui = new JPanel(new BorderLayout(p,p));
gui.setBorder(new EmptyBorder(8, 8, 8, 8));
JTextField tf = new JTextField(10);
tf.setFont(tf.getFont().deriveFont(22f));
gui.add(tf, BorderLayout.PAGE_START);
JLabel l = new JLabel("Crafted with Luv - by monsters");
gui.add(l, BorderLayout.PAGE_END);
JPanel lhs = new JPanel(new BorderLayout(p,p));
gui.add(lhs, BorderLayout.CENTER);
JPanel numpad = new JPanel(new GridLayout(3,3,p,p));
lhs.add(numpad, BorderLayout.CENTER);
for (int ii=1; ii<10; ii++) {
numpad.add(new JButton("" + ii));
}
JPanel extraButtons = new JPanel(new GridLayout(0,1,p,p));
lhs.add(extraButtons, BorderLayout.PAGE_END);
extraButtons.add(new JButton("0"));
extraButtons.add(new JButton("Reset"));
JPanel rhs = new JPanel(new GridLayout(0,1,p,p));
rhs.add(new JButton("plus"));
rhs.add(new JButton("Kurang"));
rhs.add(new JButton("BAGI"));
rhs.add(new JButton("kali"));
rhs.add(new JButton("(HASIL)"));
gui.add(rhs, BorderLayout.LINE_END);
return gui;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
Kalkulator k = new Kalkulator();
JFrame f = new JFrame("Kalkulator");
f.add(k.getGUI());
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See http://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// should be done last, to avoid flickering, moving,
// resizing artifacts.
f.setVisible(true);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
import java.awt.*;
导入javax.swing.*;
导入javax.swing.border.EmptyBorder;
公共级Kalkulator{
公共组件getGUI(){
//布局填充
int p=10;
//用户看到的GUI(无框架)
jpanelgui=newjpanel(newborderlayout(p,p));
setboorder(新的EmptyBorder(8,8,8,8));
JTextField=新的JTextField(10);
setFont(tf.getFont().deriveFont(22f));
添加(tf,BorderLayout.PAGE_START);
JLabel=新的JLabel(“用Luv制作-由怪物制作”);
添加(l,BorderLayout.PAGE_END);
JPanel lhs=新JPanel(新边界布局(p,p));
添加(左侧,BorderLayout.CENTER);
JPanel numpad=新JPanel(新网格布局(3,3,p,p));
添加(numpad,BorderLayout.CENTER);
对于(int ii=1;ii,如对现已删除的答案的评论中所述,组件未显示的原因是,在添加组件之前,GUI已设置为可见,如果没有导致框架正确布局的后续调用,组件将不会显示
这是所需GUI的粗略复制。请阅读注释中的提示。根据需要调整int p
以获得更多或更少的空间
import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class Kalkulator {
public Component getGUI() {
// layout padding
int p = 10;
// the GUI as seen by the user (without frame)
JPanel gui = new JPanel(new BorderLayout(p,p));
gui.setBorder(new EmptyBorder(8, 8, 8, 8));
JTextField tf = new JTextField(10);
tf.setFont(tf.getFont().deriveFont(22f));
gui.add(tf, BorderLayout.PAGE_START);
JLabel l = new JLabel("Crafted with Luv - by monsters");
gui.add(l, BorderLayout.PAGE_END);
JPanel lhs = new JPanel(new BorderLayout(p,p));
gui.add(lhs, BorderLayout.CENTER);
JPanel numpad = new JPanel(new GridLayout(3,3,p,p));
lhs.add(numpad, BorderLayout.CENTER);
for (int ii=1; ii<10; ii++) {
numpad.add(new JButton("" + ii));
}
JPanel extraButtons = new JPanel(new GridLayout(0,1,p,p));
lhs.add(extraButtons, BorderLayout.PAGE_END);
extraButtons.add(new JButton("0"));
extraButtons.add(new JButton("Reset"));
JPanel rhs = new JPanel(new GridLayout(0,1,p,p));
rhs.add(new JButton("plus"));
rhs.add(new JButton("Kurang"));
rhs.add(new JButton("BAGI"));
rhs.add(new JButton("kali"));
rhs.add(new JButton("(HASIL)"));
gui.add(rhs, BorderLayout.LINE_END);
return gui;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
Kalkulator k = new Kalkulator();
JFrame f = new JFrame("Kalkulator");
f.add(k.getGUI());
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See http://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// should be done last, to avoid flickering, moving,
// resizing artifacts.
f.setVisible(true);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
import java.awt.*;
导入javax.swing.*;
导入javax.swing.border.EmptyBorder;
公共级Kalkulator{
公共组件getGUI(){
//布局填充
int p=10;
//用户看到的GUI(无框架)
jpanelgui=newjpanel(newborderlayout(p,p));
setboorder(新的EmptyBorder(8,8,8,8));
JTextField=新的JTextField(10);
setFont(tf.getFont().deriveFont(22f));
添加(tf,BorderLayout.PAGE_START);
JLabel=新的JLabel(“用Luv制作-由怪物制作”);
添加(l,BorderLayout.PAGE_END);
JPanel lhs=新JPanel(新边界布局(p,p));
添加(左侧,BorderLayout.CENTER);
JPanel numpad=新JPanel(新网格布局(3,3,p,p));
添加(numpad,BorderLayout.CENTER);
对于(int ii=1;iiiBefore this.setVisible(true);user this.pack();应该为代码块使用一致的逻辑缩进。代码缩进旨在帮助人们理解程序流!顺便说一句,在获得超过2090行代码之前,您应该早就意识到存在问题。请经常编译并运行!“如何实现此布局?”是一个更好的问题(IMO)。该GUI可以使用2个边框布局和3个网格布局来实现。在此之前。setVisible(true);user this.pack();应该为代码块使用一致的逻辑缩进。代码缩进是为了帮助人们理解程序流程!顺便说一句,在获得超过2090行代码之前,您应该早就意识到存在问题。经常编译并运行!“如何实现此布局?”应该是一个更好的问题(IMO)。该GUI可以使用2个边框布局和3个网格布局实现。引用了一个说明键绑定的相关示例。谢谢。我不知道setVisible()位置是否影响程序的输出。我不理解该注释。引用了一个说明键绑定的相关示例。谢谢。我不知道setVisible()是否职位影响了程序的输出,我不理解这个评论。