Netbeans JcomboBox在单击时未打开,并将焦点释放到它旁边的一个
我想在同一个GUI中创建几个下拉列表。我想根据(x,y)来定位它们,所以我必须做:。setLayout(null); 不确定这是否导致了问题。。然而,当我尝试点击任何一个下拉列表时,它们都不会打开(只是什么都不会发生),而另一个下拉列表(同一页面中几乎没有)会获得焦点。真的很奇怪。。我肯定我做得不好。我在这里添加代码。它由3个不同的类(每个类在其自己的文件中)构建。如果任何人都可以按原样运行代码并简单地看到行为,那么您可能知道是什么导致了它。还有一件事。这些程序从一个名为:Menu.txt的文件中读取数据。该文件应位于netbeans项目的主目录中,并应具有以下行(精确的行): 文件:Menu.txt=>内容:Netbeans JcomboBox在单击时未打开,并将焦点释放到它旁边的一个,netbeans,jcombobox,Netbeans,Jcombobox,我想在同一个GUI中创建几个下拉列表。我想根据(x,y)来定位它们,所以我必须做:。setLayout(null); 不确定这是否导致了问题。。然而,当我尝试点击任何一个下拉列表时,它们都不会打开(只是什么都不会发生),而另一个下拉列表(同一页面中几乎没有)会获得焦点。真的很奇怪。。我肯定我做得不好。我在这里添加代码。它由3个不同的类(每个类在其自己的文件中)构建。如果任何人都可以按原样运行代码并简单地看到行为,那么您可能知道是什么导致了它。还有一件事。这些程序从一个名为:Menu.txt的文件
寿司片
一,
20.0
家常菜
二,
5.0
胡萝卜汤
二,
10.0
热咖啡
三,
5.0 第一个文件:ItemInMenu.java:
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JTextField;
public class ItemInMenu {
int itemAmount, itemType, maxOrderAmountPerItem=50;
double itemPrice;
String itemDisc;
JComboBox itemComboBox;
JCheckBox itemCheckBox;
JTextField itemTextField;
public ItemInMenu(double itemPrice, String itemDisc, int itemType){
this.itemCheckBox = new JCheckBox("Select Item");
this.itemTextField = new JTextField();
this.itemComboBox = new JComboBox();
this.itemAmount = 0;
this.itemType = itemType;
this.itemPrice = itemPrice;
this.itemDisc = itemDisc;
//Add options to the dropdown (max 50 items to be ordered fro meach item)
for (int i=0; i<maxOrderAmountPerItem; i++)
{
this.itemComboBox.addItem("Amount: " + i);
}
}
}
第三个文件:MyPanel.java:
import java.awt.Color;
import javax.swing.*;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;
public class MyPanel extends JPanel {
private ArrayList<ItemInMenu> itemsList = new ArrayList();
private String fileName;
public void readFromFile(String whichFile)
{
ItemInMenu newItem;
int lineNumber, itemType = -1;
Double itemPrice = -1.0;
String currentLine, itemDisc = "";
this.fileName = whichFile;
//Now lets start reading this file...
System.out.println("Reading from File: " + this.fileName);
File myFile = new File(this.fileName);
try {
lineNumber = 0;
Scanner myScanner = new Scanner(myFile);
while (myScanner.hasNext())
{
lineNumber++;
currentLine = myScanner.nextLine();
System.out.println(currentLine);
if (lineNumber == 1)
{
itemDisc = currentLine;
}
else if (lineNumber == 2)
{
itemType = Integer.parseInt(currentLine);
}
else
{
itemPrice = Double.parseDouble(currentLine);
newItem = new ItemInMenu(itemPrice, itemDisc, itemType);
this.itemsList.add(newItem);
lineNumber = 0;
}
//System.out.println(currentLine);
}
myScanner.close();
}
catch (FileNotFoundException ex)
{
System.out.println("File Not Found!");
}
}
public void printMenu(){
for (ItemInMenu tmpVar : this.itemsList)
{
System.out.println("Printing Item Details:");
System.out.print("Item Disc: " + tmpVar.itemDisc + "\nItem Price: " + tmpVar.itemPrice + "\nItem Quantity: " + tmpVar.itemAmount + "\nItem Type: " + tmpVar.itemType + "\n\n");
}
}
// The function who update the graphics of JPanel on every operation of the user (resize etc') //
public void paintComponent(Graphics g) {
int xLeftBox = 5, xCenterBox = 305, xRightBox = 605;
int yLeftBox = 5, yCenterBox = 5, yRightBox = 5;
int comboBoxWidth = 100, comboBoxHeight=25, spaceBetweenItems=100;
super.paintComponent(g);
//Now start drawing your own painting.
for (ItemInMenu tmpVar : this.itemsList)
{
if (tmpVar.itemType == 1)
{
tmpVar.itemComboBox.setBounds(xLeftBox, yLeftBox, comboBoxWidth, comboBoxHeight);
yLeftBox += spaceBetweenItems;
}
else if (tmpVar.itemType == 2)
{
tmpVar.itemComboBox.setBounds(xCenterBox, yCenterBox, comboBoxWidth, comboBoxHeight);
yCenterBox += spaceBetweenItems;
}
else
{
tmpVar.itemComboBox.setBounds(xRightBox, yRightBox, comboBoxWidth, comboBoxHeight);
yRightBox += spaceBetweenItems;
}
tmpVar.itemComboBox.setSelectedIndex(-1);
tmpVar.itemComboBox.addActionListener(
new ActionListener(){
@Override
public void actionPerformed(ActionEvent e){
JComboBox combo = (JComboBox)e.getSource();
String currentQuantity = (String)combo.getSelectedItem();
System.out.println(currentQuantity);
}
}
);
this.add(tmpVar.itemComboBox);
}
}
}
导入java.awt.Color;
导入javax.swing.*;
导入java.awt.Graphics;
导入java.awt.event.ActionEvent;
导入java.awt.event.ActionListener;
导入java.io.File;
导入java.io.FileNotFoundException;
导入java.util.ArrayList;
导入java.util.Random;
导入java.util.Scanner;
公共类MyPanel扩展了JPanel{
private ArrayList itemsList=new ArrayList();
私有字符串文件名;
public void readFromFile(字符串whichFile)
{
ItemInMenu新建项;
int lineNumber,itemType=-1;
双项目价格=-1.0;
字符串currentLine,itemDisc=“”;
this.fileName=whichFile;
//现在让我们开始读取此文件。。。
System.out.println(“从文件读取:“+this.fileName”);
File myFile=新文件(this.fileName);
试一试{
行号=0;
扫描器myScanner=新扫描器(myFile);
while(myScanner.hasNext())
{
lineNumber++;
currentLine=myScanner.nextLine();
系统输出打印项次(当前行);
如果(行号==1)
{
itemDisc=当前线路;
}
else if(行号==2)
{
itemType=Integer.parseInt(currentLine);
}
其他的
{
itemPrice=Double.parseDouble(currentLine);
newItem=新建ItemInMenu(itemPrice、itemDisc、itemType);
this.itemsList.add(newItem);
行号=0;
}
//系统输出打印项次(当前行);
}
myScanner.close();
}
捕获(FileNotFoundException ex)
{
System.out.println(“未找到文件!”);
}
}
公共无效打印菜单(){
for(ItemInMenu tmpVar:this.itemsList)
{
System.out.println(“打印项目详细信息:”);
系统输出打印(“项目光盘:+tmpVar.itemDisc+”\nItem价格:+tmpVar.itemPrice+”\nItem数量:+tmpVar.itemAmount+“\nItem类型:+tmpVar.itemType+”\n\n”);
}
}
//在用户每次操作时更新JPanel图形的功能(调整大小等)//
公共组件(图形g){
int-xLeftBox=5,xCenterBox=305,xRightBox=605;
int yLeftBox=5,yCenterBox=5,yRightBox=5;
int comboBoxWidth=100,comboBoxHeight=25,spaceBetweenItems=100;
超级组件(g);
//现在开始画你自己的画。
for(ItemInMenu tmpVar:this.itemsList)
{
if(tmpVar.itemType==1)
{
tmpVar.itemComboBox.setBounds(xLeftBox、yLeftBox、comboBoxWidth、ComboxHeight);
yLeftBox+=元素之间的空格;
}
else if(tmpVar.itemType==2)
{
tmpVar.itemComboBox.setBounds(xCenter框、cCenter框、comboBoxWidth、ComboxHeight);
cEnterBox+=元素之间的空格;
}
其他的
{
tmpVar.itemComboBox.setBounds(xRightBox、yRightBox、comboBoxWidth、ComboxHeight);
yRightBox+=元素之间的空格;
}
tmpVar.itemComboBox.setSelectedIndex(-1);
tmpVar.itemComboBox.addActionListener(
新建ActionListener(){
@凌驾
已执行的公共无效操作(操作事件e){
JComboBox组合=(JComboBox)e.getSource();
字符串currentQuantity=(字符串)组合。getSelectedItem();
系统输出打印项次(当前数量);
}
}
);
this.add(tmpVar.itemComboBox);
}
}
}
希望你运行得很好。。感谢您的帮助。问题似乎是。添加内部paintComponent函数。它不应该在它里面,因为它再次添加了很多组件,而且似乎会导致问题
import java.awt.Color;
import javax.swing.*;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;
public class MyPanel extends JPanel {
private ArrayList<ItemInMenu> itemsList = new ArrayList();
private String fileName;
public void readFromFile(String whichFile)
{
ItemInMenu newItem;
int lineNumber, itemType = -1;
Double itemPrice = -1.0;
String currentLine, itemDisc = "";
this.fileName = whichFile;
//Now lets start reading this file...
System.out.println("Reading from File: " + this.fileName);
File myFile = new File(this.fileName);
try {
lineNumber = 0;
Scanner myScanner = new Scanner(myFile);
while (myScanner.hasNext())
{
lineNumber++;
currentLine = myScanner.nextLine();
System.out.println(currentLine);
if (lineNumber == 1)
{
itemDisc = currentLine;
}
else if (lineNumber == 2)
{
itemType = Integer.parseInt(currentLine);
}
else
{
itemPrice = Double.parseDouble(currentLine);
newItem = new ItemInMenu(itemPrice, itemDisc, itemType);
this.itemsList.add(newItem);
lineNumber = 0;
}
//System.out.println(currentLine);
}
myScanner.close();
}
catch (FileNotFoundException ex)
{
System.out.println("File Not Found!");
}
}
public void printMenu(){
for (ItemInMenu tmpVar : this.itemsList)
{
System.out.println("Printing Item Details:");
System.out.print("Item Disc: " + tmpVar.itemDisc + "\nItem Price: " + tmpVar.itemPrice + "\nItem Quantity: " + tmpVar.itemAmount + "\nItem Type: " + tmpVar.itemType + "\n\n");
}
}
// The function who update the graphics of JPanel on every operation of the user (resize etc') //
public void paintComponent(Graphics g) {
int xLeftBox = 5, xCenterBox = 305, xRightBox = 605;
int yLeftBox = 5, yCenterBox = 5, yRightBox = 5;
int comboBoxWidth = 100, comboBoxHeight=25, spaceBetweenItems=100;
super.paintComponent(g);
//Now start drawing your own painting.
for (ItemInMenu tmpVar : this.itemsList)
{
if (tmpVar.itemType == 1)
{
tmpVar.itemComboBox.setBounds(xLeftBox, yLeftBox, comboBoxWidth, comboBoxHeight);
yLeftBox += spaceBetweenItems;
}
else if (tmpVar.itemType == 2)
{
tmpVar.itemComboBox.setBounds(xCenterBox, yCenterBox, comboBoxWidth, comboBoxHeight);
yCenterBox += spaceBetweenItems;
}
else
{
tmpVar.itemComboBox.setBounds(xRightBox, yRightBox, comboBoxWidth, comboBoxHeight);
yRightBox += spaceBetweenItems;
}
tmpVar.itemComboBox.setSelectedIndex(-1);
tmpVar.itemComboBox.addActionListener(
new ActionListener(){
@Override
public void actionPerformed(ActionEvent e){
JComboBox combo = (JComboBox)e.getSource();
String currentQuantity = (String)combo.getSelectedItem();
System.out.println(currentQuantity);
}
}
);
this.add(tmpVar.itemComboBox);
}
}
}