Java 是否有任何方法可以将滚动窗格添加到jlist，并将其添加到具有空布局的面板上？
我正在做一个基于医学商店的学校项目，我想在我使用的所有3个列表中添加一个滚动窗格Java 是否有任何方法可以将滚动窗格添加到jlist，并将其添加到具有空布局的面板上？,java,swing,Java,Swing,我正在做一个基于医学商店的学校项目，我想在我使用的所有3个列表中添加一个滚动窗格 package Interfata; import java.awt.Color; import java.awt.GridBagLayout; import java.awt.event.ActionListener; import java.awt.event.FocusEvent; import java.awt.event.FocusListener; import java.io.BufferedRea
package Interfata;
import java.awt.Color;
import java.awt.GridBagLayout;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing. * ;
import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.SwingUtilities;
public class Home extends JFrame {
JPanel panelHome;
static String[] listaplante = new String[10];
static String[] listacantitati = new String[10];
static String[] listapreturi = new String[10];
static int kPlante = 0,
kCantitati = 0,
kPreturi = 0;
JButton butonCumpara,
butonAdauga;
JTextField denumireField,
pretField,
cantitateField,
cantitateDoritaField;
public JPanel createHomeContentPane() {
//Creez un panel pe care sa pun toate campurile.
panelHome = new JPanel();
panelHome.setLayout(null);
panelHome.setBackground(new java.awt.Color(204, 204, 255));
panelHome.setBorder(javax.swing.BorderFactory.createTitledBorder("Home"));
//Creez lista cu plante
DefaultListModel < String > listaPlante = new DefaultListModel < >();
JList < String > list = new JList < >(citirePlante());
list.setBounds(50, 75, 75, 100);
list.setSelectionBackground(Color.ORANGE);
panelHome.add(list);
//Creez lista cu cantitatile fiecarei plante
DefaultListModel < String > listaCantitati = new DefaultListModel < >();
JList < String > list2 = new JList < >(citireCantitati());
list2.setBounds(150, 75, 75, 100);
list2.setSelectionBackground(Color.YELLOW);
panelHome.add(list2);
//Creez lista cu preturile fiecarei plante
DefaultListModel < String > listaPreturi = new DefaultListModel < >();
JList < String > list3 = new JList < >(citirePreturi());
list3.setBounds(250, 75, 75, 100);
list3.setSelectionBackground(Color.GREEN);
panelHome.add(list3);
//Creez titlurile pt fiecare lista
JLabel denumireLabel = new JLabel("Denumire:");
denumireLabel.setBounds(50, 55, 70, 20);
panelHome.add(denumireLabel);
JLabel cantitatiLabel = new JLabel("Cantitati:");
cantitatiLabel.setBounds(150, 55, 70, 20);
panelHome.add(cantitatiLabel);
JLabel preturiLabel = new JLabel("Preturi:");
preturiLabel.setBounds(250, 55, 70, 20);
panelHome.add(preturiLabel);
//Creez un camp pt a adauga cantitatea dorita care urmeaza a fi cumparata
//cantitateDoritaField
cantitateDoritaField = new JTextField();
cantitateDoritaField.setBounds(80, 200, 100, 20);
cantitateDoritaField.setHorizontalAlignment(JTextField.CENTER);
//placeholder pt cantitateField
final String placeholderCantitateDorita = "Cantitatea dorita";
cantitateDoritaField.setText(placeholderCantitateDorita);
cantitateDoritaField.addFocusListener(new FocusListener() {
private boolean showingPlaceholder = true;
public void focusGained(FocusEvent e) {
if (showingPlaceholder) {
showingPlaceholder = false;
cantitateDoritaField.setText("");
}
}
public void focusLost(FocusEvent arg0) {
if (cantitateDoritaField.getText().isEmpty()) {
cantitateDoritaField.setText(placeholderCantitateDorita);
showingPlaceholder = true;
}
}
});
panelHome.add(cantitateDoritaField);
//Butonul de cumparare
butonCumpara = new JButton("Cumpara");
butonCumpara.setLocation(180, 200);
butonCumpara.setSize(100, 20);
butonCumpara.addActionListener(new ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
String plantaselectata = list.getSelectedValue();
int indexplanta = list.getSelectedIndex();
String cantitateselectata = list2.getSelectedValue();
int indexcantitate = list2.getSelectedIndex();
String pretselectat = list3.getSelectedValue();
int indexpret = list3.getSelectedIndex();
String cantitatedorita = cantitateDoritaField.getText();
int valCantitate = Integer.valueOf(cantitateselectata);
int valCantitateDorita = Integer.valueOf(cantitatedorita);
int valPret = Integer.valueOf(pretselectat);
if (indexplanta == indexcantitate && indexplanta == indexpret) {
if (valCantitateDorita <= valCantitate) {
try {
afisPlantaCumparata(plantaselectata, valCantitateDorita);
} catch(IOException ex) {
Logger.getLogger(Home.class.getName()).log(Level.SEVERE, null, ex);
}
int a = valCantitate - valCantitateDorita;
String b = Integer.toString(a);
listacantitati[indexcantitate] = b;
panelHome.setVisible(false);
panelHome.setVisible(true);
}
else {
JFrame rootPane = null;
JOptionPane.showMessageDialog(rootPane, "Cantitatea nu esti disponibila", "Eroare de cumparare", JOptionPane.WARNING_MESSAGE);
}
}
else {
JFrame rootPane = null;
JOptionPane.showMessageDialog(rootPane, "Planta, cantitate si pretul nu sunt din aceeasi categorie", "Eroare de cumparare", JOptionPane.WARNING_MESSAGE);
}
}
});
panelHome.add(butonCumpara);
//Cumpurile denumire cantitate si pret pt adaugarea plantei
//denumireField
denumireField = new JTextField();
denumireField.setBounds(80, 240, 100, 20);
denumireField.setHorizontalAlignment(JTextField.CENTER);
//placeholder pt denumireField
final String placeholderDenumire = "Denumire";
denumireField.setText(placeholderDenumire);
denumireField.addFocusListener(new FocusListener() {
private boolean showingPlaceholder = true;
public void focusGained(FocusEvent e) {
if (showingPlaceholder) {
showingPlaceholder = false;
denumireField.setText("");
}
}
public void focusLost(FocusEvent arg0) {
if (denumireField.getText().isEmpty()) {
denumireField.setText(placeholderDenumire);
showingPlaceholder = true;
}
}
});
panelHome.add(denumireField);
//cantitateField
cantitateField = new JTextField();
cantitateField.setBounds(80, 260, 100, 20);
cantitateField.setHorizontalAlignment(JTextField.CENTER);
//placeholder pt cantitateField
final String placeholderCantitate = "Cantitatea";
cantitateField.setText(placeholderCantitate);
cantitateField.addFocusListener(new FocusListener() {
private boolean showingPlaceholder = true;
public void focusGained(FocusEvent e) {
if (showingPlaceholder) {
showingPlaceholder = false;
cantitateField.setText("");
}
}
public void focusLost(FocusEvent arg0) {
if (cantitateField.getText().isEmpty()) {
cantitateField.setText(placeholderCantitate);
showingPlaceholder = true;
}
}
});
panelHome.add(cantitateField);
//pretField
pretField = new JTextField();
pretField.setBounds(80, 280, 100, 20);
pretField.setHorizontalAlignment(JTextField.CENTER);
//placeholder pt pretField
final String placeholderPret = "Pret";
pretField.setText(placeholderPret);
pretField.addFocusListener(new FocusListener() {
private boolean showingPlaceholder = true;
public void focusGained(FocusEvent e) {
if (showingPlaceholder) {
showingPlaceholder = false;
pretField.setText("");
}
}
public void focusLost(FocusEvent arg0) {
if (pretField.getText().isEmpty()) {
pretField.setText(placeholderPret);
showingPlaceholder = true;
}
}
});
panelHome.add(pretField);
//Butonul de adaugare a unei plantei noi
butonAdauga = new JButton("Adauga");
butonAdauga.setLocation(180, 260);
butonAdauga.setSize(100, 20);
butonAdauga.addActionListener(new ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
String denumireNou = denumireField.getText();
String cantitateNou = cantitateField.getText();
String pretNou = pretField.getText();
listaplante[kPlante++] = denumireNou;
listacantitati[kCantitati++] = cantitateNou;
listapreturi[kPreturi++] = pretNou;
panelHome.setVisible(false);
panelHome.setVisible(true);
}
});
panelHome.add(butonAdauga);
//Returnez panelul
panelHome.setOpaque(true);
return panelHome;
}
public static String[] citirePlante() {
BufferedReader objReader = null;
try {
String strCurrentLine;
objReader = new BufferedReader(new FileReader("Plante.txt"));
while ((strCurrentLine = objReader.readLine()) != null) {
listaplante[kPlante] = strCurrentLine;
kPlante++;
}
} catch(IOException e) {
e.printStackTrace();
} finally {
try {
if (objReader != null) objReader.close();
} catch(IOException ex) {
ex.printStackTrace();
}
}
return listaplante;
}
public static String[] citireCantitati() {
BufferedReader objReader = null;
try {
String strCurrentLine;
objReader = new BufferedReader(new FileReader("Cantitati.txt"));
while ((strCurrentLine = objReader.readLine()) != null) {
listacantitati[kCantitati] = strCurrentLine;
kCantitati++;
}
} catch(IOException e) {
e.printStackTrace();
} finally {
try {
if (objReader != null) objReader.close();
} catch(IOException ex) {
ex.printStackTrace();
}
}
return listacantitati;
}
public static String[] citirePreturi() {
BufferedReader objReader = null;
try {
String strCurrentLine;
objReader = new BufferedReader(new FileReader("Preturi.txt"));
while ((strCurrentLine = objReader.readLine()) != null) {
listapreturi[kPreturi] = strCurrentLine;
kPreturi++;
}
} catch(IOException e) {
e.printStackTrace();
} finally {
try {
if (objReader != null) objReader.close();
} catch(IOException ex) {
ex.printStackTrace();
}
}
return listapreturi;
}
public static void afisPlantaCumparata(String p, int c) throws IOException {
FileWriter writer = new FileWriter("PlanteVandute.txt", true);
try (
BufferedWriter bw = new BufferedWriter(writer)) {
bw.write(p + " " + c + "\n");
} catch(IOException e) {
System.err.format("IOException: %s%n", e);
}
}
private static void Home() {
JFrame frameHome = new JFrame("PLAFAR * Calinescu George-Catalin * 221");
//Creez panelul peste frame si il stilizez
Home home = new Home();
frameHome.setContentPane(home.createHomeContentPane());
frameHome.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frameHome.setSize(400, 350);
frameHome.setVisible(true);
}
public static void main(String[] args) {
//Creez GUI si il afisez pe ecran
SwingUtilities.invokeLater(new Runnable() {
public void run() {
Home();
}
});
}
}
package-interdata；
导入java.awt.Color；
导入java.awt.GridBagLayout；
导入java.awt.event.ActionListener；
导入java.awt.event.FocusEvent；
导入java.awt.event.FocusListener；
导入java.io.BufferedReader；
导入java.io.BufferedWriter；
导入java.io.FileReader；
导入java.io.FileWriter；
导入java.io.IOException；
导入java.util.logging.Level；
导入java.util.logging.Logger；
导入javax.swing.*；
导入javax.swing.DefaultListModel；
导入javax.swing.JFrame；
导入javax.swing.JList；
导入javax.swing.SwingUtilities；
公共类家庭扩展JFrame{
JPanel panelHome；
静态字符串[]ListaPlane=新字符串[10]；
静态字符串[]ListaAntitati=新字符串[10]；
静态字符串[]listapreturi=新字符串[10]；
静态int kPlante=0，
KCantati=0，
kPreturi=0；
朱布顿·布顿坎帕拉，
布托纳道加；
JTextField denumireField，
普雷特菲尔德，
坎蒂特菲尔德，
坎蒂塔菲尔德；
公共JPanel createHomeContentPane（）{
//Creez un panel pe care sa pun toate露营酒店。
panelHome=新的JPanel（）；
panelHome.setLayout（null）；
setBackground（新的java.awt.Color（204204255））；
setboorder（javax.swing.BorderFactory.createTitledBorder（“Home”））；
//克里兹利斯塔工厂
DefaultListModelListaPlane=新的DefaultListModel<>（）；
JListlist=newjlist<>（citirePlante（））；
列表.立根（50,75,75,100）；
list.setSelectionBackground（橙色）；
panelHome.add（列表）；
//克里兹·利斯塔cu Cantitile fiecarei植物园
DefaultListModelListaAntitati=新的DefaultListModel<>（）；
JListlist2=新JList<>（citirecantati（））；
清单2.立根（150,75,75,100）；
列表2.setSelectionBackground（颜色：黄色）；
panelHome.add（列表2）；
//克里兹·利斯塔·普雷图里勒·菲卡雷普兰特酒店
DefaultListModellistaPreturi=新的DefaultListModel<>（）；
JListlist3=新JList<>（citirePreturi（））；
清单3.挫折（250、75、75、100）；
列表3.setSelectionBackground（颜色为绿色）；
panelHome.add（列表3）；
//克里兹提尔里尔pt菲卡雷利斯塔酒店
JLabel denumireLabel=新JLabel（“Denumire:”）；
denumireLabel.挫折（50,55,70,20）；
panelHome.add（denumireLabel）；
JLabel-CantititLabel=新的JLabel（“Cantitit:”）；
弯曲度.立根（150,55,70,20）；
panelHome.add（标签）；
JLabel preturiLabel=新的JLabel（“Preturi:”）；
前庭标签.立根（250,55,70,20）；
panelHome.add（preturiLabel）；
//Creez联合国难民营是一个康蒂塔康蒂塔多丽塔护理中心
//坎蒂塔菲尔德酒店
cantitateDoritaField=新的JTextField（）；
坎蒂塔德多里塔菲尔德.立根（8020010020）；
设置水平对齐（JTextField.CENTER）；
//占位符pt cantitateField
最后一个字符串占位符cantitatedorita=“Cantitatea dorita”；
setText（占位符cantitatedorita）；
addFocusListener（新FocusListener（））{
私有布尔值showingPlaceholder=true；
获得公共无效焦点（焦点事件e）{
如果（显示占位符）{
showingPlaceholder=false；
cantitateDoritaField.setText（“”）；
}
}
public void focusLost（FocusEvent arg0）{
if（cantitateDoritaField.getText（）.isEmpty（））{
setText（占位符cantitatedorita）；
showingPlaceholder=true；
}
}
});
panelHome.add（cantitateDoritaField）；
//康帕拉雷丁醇
butonCumpara=新的JButton（“Cumpara”）；
butonCumpara.设置位置（180200）；
butonCumpara.setSize（100,20）；
butonCumpara.addActionListener（新ActionListener（）{
public void actionPerformed（java.awt.event.ActionEvent evt）{
字符串plantaselectata=list.getSelectedValue（）；
int indexplanta=list.getSelectedIndex（）；
字符串cantitateselectata=list2.getSelectedValue（）；
int indexcantate=list2.getSelectedIndex（）；
字符串pretselectat=list3.getSelectedValue（）；
int indexpret=list3.getSelectedIndex（）；
字符串cantitatedorita=cantitateDoritaField.getText（）；
int valCantitate=整数.valueOf（cantitateselectata）；
int valCantitateDorita=Integer.valueOf（cantitatedorita）；
int valPret=Integer.valueOf（pretselectat）；
if（indexplanta==indexcantate&&indexplanta==indexpret）{
if（valCantitateDorita感谢您提供示例代码/最小工作示例。（一句话-如果未发现Plante.txt
，将引发异常。您可以改进代码以处理此行为，例如，向用户发出警告或消息。）
您可以将JList
添加到JScrollPane
中，如下所示：
// to ensure single selection in your list
someList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
JScrollPane scrollPane = new JScrollPane(someList);
然后，您必须将scollPane
添加到LayoutManager
或（在您的示例中）JPanel
强烈建议使用普通布局管理器，因为布局管理器允许在调整窗口/面板大小时处理组件大小。它还为不同的和操作系统提供更好的支持
要使代码正常工作，您需要在列表周围安装滚动窗格
DefaultListModel<String> listaPlante = new DefaultListModel<>();
JList<String> list = new JList<>(citirePlante());
JScrollPane scroller = new JScrollPane(list);
scroller.setBounds(50,75, 75,100); // not list!!!
list.setSelectionBackground(Color.ORANGE);
panelHome.add(scroller); // not list!!!
DefaultListModel listaplant=newdefaultlistmodel（）；
JList列表=新的JList（c