Question

以下示例： http://code.makery.ch/blog/javafx-8-event-handling-examples/ 我已经制作了一个涉及组合框的基本GUI。在运行我的程序时，没有任何项目被添加到组合框中。如果你能指出我的错误，为什么它可能不会将这些项目添加到组合框中，我将非常感激。这是我的项目的ZIP文件： https://www.dropbox.com/home/Project-JavaFX 提前谢谢！

Main.java：

package Main;

import Items.Item;
import Items.ItemManager;
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

public class Main extends Application {

private static myController uj = new myController();
private static ItemManager im = new ItemManager();


public static void main(String[] args) {
    uj.initialize();
    launch(args);

}

@Override
public void start(Stage primaryStage) throws Exception {
    Pane mainPane = (Pane) FXMLLoader.load(Main.class.getResource("Main.fxml"));
    primaryStage.setScene(new Scene(mainPane));
    primaryStage.show();
}
}

Main.fxml：

<?xml version="1.0" encoding="UTF-8"?>

<?import java.net.*?>
<?import java.lang.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.image.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.shape.*?>
<?import javafx.scene.text.*?>
<?import javafx.scene.layout.AnchorPane?>

<Pane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="720.0" prefWidth="1280.0" stylesheets="@myStyle.css" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="Main.myController">
   <children>
      <Rectangle arcHeight="5.0" arcWidth="5.0" fill="WHITE" height="196.0" layoutX="478.0" layoutY="-2.0" stroke="BLACK" strokeType="INSIDE" width="343.0" />
      <ImageView fitHeight="568.0" fitWidth="684.0" layoutX="356.0" layoutY="167.0" pickOnBounds="true" preserveRatio="true">
         <image>
            <Image url="@../../../../Pictures/builder.jpg" />
         </image>
      </ImageView>
      <ImageView fitHeight="885.0" fitWidth="857.0" layoutX="629.0" layoutY="187.0" pickOnBounds="true" preserveRatio="true" rotate="90.0">
         <image>
             <Image url="@../../../../Pictures/Uroburos-rootkit-Espionage-Russia.jpg" />
         </image>
      </ImageView>
      <ImageView fitHeight="885.0" fitWidth="857.0" layoutX="-187.0" layoutY="187.0" pickOnBounds="true" preserveRatio="true" rotate="90.0">
         <image>
            <Image url="@../../../../Pictures/Uroburos-rootkit-Espionage-Russia.jpg" />
         </image>
      </ImageView>
      <Line endX="100.0" endY="400.0" layoutX="381.0" layoutY="324.0" startX="100.0" startY="-325.0" />
      <Line endX="425.0" endY="390.0" layoutX="391.0" layoutY="334.0" startX="425.0" startY="-335.0" />
      <ComboBox fx:id="stocks" layoutX="38.0" layoutY="135.0" onAction="#itemPicked" prefHeight="46.0" prefWidth="421.0" promptText="Please Select and Item" />
      <ScrollBar fx:id="currentP" layoutX="857.0" layoutY="108.0" onDragDetected="#getIndexC" orientation="VERTICAL" prefHeight="100.0" prefWidth="400.0" />
      <Button fx:id="remove" layoutX="1007.0" layoutY="53.0" mnemonicParsing="false" onAction="#deleteItem" prefHeight="43.0" prefWidth="250.0" text="Remove From Order">
         <font>
            <Font name="Arial Black" size="20.0" />
         </font>
      </Button>
      <ImageView fitHeight="72.0" fitWidth="79.0" layoutX="491.0" layoutY="74.0" pickOnBounds="true" preserveRatio="true">
         <image>
            <Image url="@../../../../Pictures/Uroburos-rootkit-Espionage-Russia.jpg" />
         </image>
      </ImageView>
      <Label layoutX="491.0" layoutY="14.0" prefHeight="60.0" prefWidth="311.0" text="RootKit At your Service" textAlignment="JUSTIFY">
         <font>
            <Font name="Courier New Bold Italic" size="22.0" />
         </font>
      </Label>
      <Label fx:id="message" layoutX="587.0" layoutY="87.0" text="&quot;Protecting&quot; your trade">
         <font>
            <Font name="Courier New Italic" size="15.0" />
         </font>
      </Label>
      <Button fx:id="adding" layoutX="38.0" layoutY="81.0" mnemonicParsing="false" onAction="#addItem" text="Add Item To Order">
         <font>
            <Font name="Arial Black" size="20.0" />
         </font>
      </Button>
      <TextField fx:id="quantity" layoutX="38.0" layoutY="194.0" onAction="#getQuantity" prefHeight="54.0" prefWidth="62.0" promptText="&quot;1&quot;">
         <font>
            <Font size="20.0" />
         </font></TextField>
      <Label layoutX="108.0" layoutY="196.0" text="Quantity" textFill="WHITE">
         <font>
            <Font name="Arial Black" size="34.0" />
         </font>
      </Label>
   </children>
</Pane>

myController.java：

package Main;

import Items.Item;
import Items.ItemManager;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Label;
import javafx.scene.control.ScrollBar;
import javafx.scene.control.TextField;

public class myController {

@FXML
private TextField quantity;

@FXML
private Button adding;

@FXML
private ScrollBar currentP;

@FXML
private Label message;

@FXML
public static ComboBox stocks = new ComboBox();

@FXML
private Button remove;

public static ObservableList<String> options = FXCollections.observableArrayList();

int count = 0;

private static ItemManager im = new ItemManager();


@FXML
void itemPicked(ActionEvent event) {

}


@FXML
void getIndexC(ActionEvent event) {

}

@FXML
void deleteItem(ActionEvent event) {

}

@FXML
void addItem(ActionEvent event) {

}

@FXML
void getQuantity(ActionEvent event) {

}


public void initialize() {
    // TODO Auto-generated method stub
    for(int i = 0; i < im.inventoryItems.size(); i++) {
        options.add(im.inventoryItems.get(i).getName());
    }
    stocks.setItems(options);
}

}

Item.java：

package Items;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;

public class Item {

//Items definitions

public static Item hammer = new Item(0, "Hammer", 5.0);
public static Item tape = new Item(1, "Tape", 3.0);
public static Item test = new Item(2, "Rare", 4.0);

protected int quantity, id;
protected String name;
protected BufferedImage sprite;
protected double price, totalPrice;

public static void updateTotalPrice(Item i) {
    i.setTotalPrice(i.getQuantity()*i.getPrice());
}

public Item (int id, String name, double price) {
    this.id = id;
    this.name = name;
    this.price = price;
    //quantity = 1;
    //this.totalPrice = price;
}

//Getters and Setters

public int getQuantity() {
    return quantity;
}

public double getTotalPrice() {
    return totalPrice;
}

public void setTotalPrice(double totalPrice) {
    this.totalPrice = totalPrice;
}

public void setQuantity(int quantity) {
    this.quantity = quantity;
}

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public double getPrice() {
    return price;
}

public void setPrice(double price) {
    this.price = price;
}



}

ItemManager.java：

package Items;

import java.util.ArrayList;

public class ItemManager {

public static ArrayList<Item> inventoryItems;

public static void ItemManager() {
    inventoryItems = new ArrayList<Item>();
    inventoryItems.add(Item.hammer);
    inventoryItems.add(Item.tape);
    inventoryItems.add(Item.test);
}

public Item getItemFromID(int id) {
    for (Item i : inventoryItems) {
        if (i.getId() == id) {
            return i;
        }
    }
    return null;
}

public void addItem(Item i, int quantity) {
    boolean flag = false;
    for (Item item : inventoryItems) {
        if (i.getId() == item.getId()) {
            item.setQuantity(item.getQuantity()+quantity);
            Item.updateTotalPrice(item);
            flag = true;
            //call the method to update the information box in the inventory GUI
            break;
        }
    }
    if (!flag) {
        inventoryItems.add(i);
        //call method for adding new info box in inventory GUI
    }
}

public void removeItem(int id) {
    for (Item item : inventoryItems) {
        if (item.getId() == this.getItemFromID(id).getId()) {
            item.setQuantity(item.getQuantity()-1);
            if (item.getQuantity() <= 0) {
                inventoryItems.remove(item);
            }
            break;
        }
    }
}

//Getters and Setters



}

Answer 1

我建议改变一些事项：

主要班级

private static myController uj = new myController();
private static ItemManager im = new ItemManager();

以及

uj.initialize();

应从Main课程中删除。控制器的initialize方法由FXMLLoader自动调用。此外，uj与您的fxml使用的实例不同。 im字段是不必要的，因为它从未在类中使用过。

ItemManager类

public static void ItemManager() {
    inventoryItems = new ArrayList<Item>();
    inventoryItems.add(Item.hammer);
    inventoryItems.add(Item.tape);
    inventoryItems.add(Item.test);
}

这既不是构造函数也不是创建对象的方法。它从未使用过，但它似乎服务于“静态构造函数”的目的。您应该使用静态初始化程序来初始化static字段：

public final static ArrayList<Item> inventoryItems;

static {
    inventoryItems = new ArrayList<Item>();
    inventoryItems.add(Item.hammer);
    inventoryItems.add(Item.tape);
    inventoryItems.add(Item.test);
}

此外，static类中存在ItemsManager数据和非静态方法的不健康混合。我建议使用正确的

mainController类

@FXML
public static ComboBox stocks = new ComboBox();

fxml元素不会注入静态字段。因此，该字段应更改为：

@FXML
private ComboBox stocks;

另外，我建议使用非静态options字段或在static初始化程序中初始化的字段，因为多次加载场景会导致相同的项目反复添加。

此外，如果您想保留ItemManager.inventoryItems字段static，im字段是不必要的，您只使用该类的static成员，这是不好的做法，也是不必要的您可以使用类名而不是实例：

public void initialize() {
    // TODO Auto-generated method stub
    for (int i = 0; i < ItemManager.inventoryItems.size(); i++) {
        options.add(ItemManager.inventoryItems.get(i).getName());
    }
    stocks.setItems(options);
}

FXML和Comboboxes

1 个答案:

主要班级

ItemManager类

mainController类