Programımı% 100

Question

kapalı kapladığı ürün satışlarının% 'sini güncelleme programımı nasıl alırım Temelde, programım bir satış değeri alır ve güncellenir. Program aynı zamanda, bu ürünün bir araya getirilen tüm ürünlerin toplam satışını oluşturan yüzde 100'ünü de güncellemesi gerekiyor. Örneğin, havuç için 100 satış girdiysem, tüm satışların% 100'ü olmalıdır çünkü bu, satılan tek ürün ve sadece 100 satış var. Potatos'a belki 100 satış eklediğinizde, ikisi arasında 200 satış olduğu için% 'si her biri için% 50'ye dönüşecektir. Bunun olmasını nasıl kodlarım. Deneme kodum aşağıda eklenmiştir, başka sorular aşağıda yorumda bulunabilir.

Sorun, hesaplama yüzdesi yönteminde ve yüzde ile başlayan güncelleştirme ölçeklendirme yöntemindeki ifadedir. Ben bu nedenle her zaman onun altında en yakın tam sayıya yuvarlanır alır, belirli bir ürün

import java.awt.*; 
import java.awt.event.*; 
import javax.swing.*; 

/** 
This is an initial starter version of a Java application that should be 
extended in stages, eventually allowing the user to enter product sales figures 
for a number of products, and display them in a table with %ages, a ranking and a pie chart. 

This starter code just has storage for one product, and allows that product's sales figure 
to be updated and displayed. The display is plain, with no font changes and 
no border lines for the table. All the processing is limited to just this one product, 
and must be adapted for a whole array of products. 

SBJ March 2016 
*/ 

public class ProductChart extends JFrame implements ActionListener 
{ 
    /** 
    * Frame constants 
    */ 
    private static final int FRAME_LOCATION_X = 350; 
    private static final int FRAME_LOCATION_Y = 250; 
    private static final int FRAME_WIDTH = 650; 
    private static final int FRAME_HEIGHT = 400; 

    /** 
    * The maximum permitted number of products 
    */ 
    private final int MAX_PRODUCTS = 10; 

    /** 
    * These arrays holds all the sales data: 
    * Element 0 is unused, so array sizes are MAX_PRODUCTS+1. 
    * The product number (from 1 to MAX_PRODUCTS) is the index in the arrays 
    * where the product's data is held. 
    * Sales figures are counted quantities, so int. 
    */ 
    private String[] productName; // The name of each product 
    private int[] productSales; // The number of sales of each product 
    private float[] percentage; // The proportion of total sales for each product 

    private int totalSales;  // Always the current total sales 

    /** 
    * Display area layout constants 
    */ 
    private final int DISPLAY_WIDTH = 600; 
    private final int DISPLAY_HEIGHT = 300; 
    private final int PRODUCT_X = 30; // Start of product number column 
    private final int NAME_X = 75;  // Start of product name column 
    private final int SALES_X = 225; // Start of sales column 
    private final int PERCENTAGE_X = 300; //Start of percentage column 
    private final int TABLE_LINES_Y = 12; //The number of horizontal lines required to draw the table 
    private final int TABLE_LINES_X = 5; //The number of vertical "" 

    /** 
    * The main launcher method: 
    * Configure the applications's window, initialize the sales data structures, 
    * and make the applications visible. 
    * @param args Unused 
    */ 
    public static void main(String[] args) 
    { 
     ProductChart frame = new ProductChart(); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.setLocation(FRAME_LOCATION_X, FRAME_LOCATION_Y); 
     frame.setSize(FRAME_WIDTH, FRAME_HEIGHT); 
     frame.initializeSalesData(); 
     frame.createGUI(); 
     frame.setVisible(true); 
     frame.setTitle("Product Chart 2312931"); 

    } 

    /** 
    * The GUI components 
    */ 
    private JTextField productSalesEntryField; // For entry of new product sales figures 
    private JButton updateSalesButton;   // To request update of a sales figure 
    private JPanel displayArea;     // Graphics area for drawing the sales table 
    private JTextField productRefEntryField; // For entry of product refence number when updating sales figures 

    /** 
    * Helper method to build the GUI 
    */ 
    private void createGUI() 
    { 
     // Standard window set up 
     Container window = getContentPane(); 
     window.setLayout(new FlowLayout()); 
     window.setBackground(Color.lightGray); 

     // Product reference entry label and text field 
     JLabel productRefEntryLabel = new JLabel("Product Ref #:"); 
     productRefEntryField = new JTextField(2); 
     window.add(productRefEntryLabel); 
     window.add(productRefEntryField);  

     // Product sales entry label and text field 
     JLabel productSalesEntryLabel = new JLabel("Product sales:"); 
     productSalesEntryField = new JTextField(5); 
     window.add(productSalesEntryLabel); 
     window.add(productSalesEntryField); 

     // Button to add new sales figure 
     updateSalesButton = new JButton("Update sales"); 
     updateSalesButton.addActionListener(this); 
     window.add(updateSalesButton); 

     // The drawing area for displaying all data 
     displayArea = new JPanel() 
     { 
      // paintComponent is called automatically when a screen refresh is needed 
      public void paintComponent(Graphics g) 
      { 
       // g is a cleared panel area 
       super.paintComponent(g); // Paint the panel's background 
       paintScreen(g);   // Then the required graphics 
      } 
     }; 
     displayArea.setPreferredSize(new Dimension(DISPLAY_WIDTH, DISPLAY_HEIGHT)); 
     displayArea.setBackground(Color.white); 
     window.add(displayArea); 
    } 

    /** 
    * Initializes product arrays: 
    * A set of product names, 
    * With sales initially 0. 
    * 
    * Note: In the arrays, the first element is unused, so Bread is at index 1 
    */ 
    private void initializeSalesData() 
    { 
     productName = new String[MAX_PRODUCTS+1]; 
     productName[1] = "Bread"; // Note: First element is unused, so Bread is at index 1 
     productName[2] = "Milk"; 
     productName[3] = "Eggs"; 
     productName[4] = "Cheese"; 
     productName[5] = "Cream"; 
     productName[6] = "Butter"; 
     productName[7] = "Jam"; 
     productName[8] = "Chocolate Spread"; 
     productName[9] = "Corn Flakes"; 
     productName[10] = "Sugar"; 

     productSales = new int[MAX_PRODUCTS+1]; 
     for(int i=0; i< MAX_PRODUCTS; i++) 
     { 
      productSales[i] = 0; 
     } 

     percentage = new float[MAX_PRODUCTS+1]; 
     for(int i=0; i< MAX_PRODUCTS; i++) 
     { 
      percentage[i] = 0; 
     } 

    } 

    /** 
    * Event handler for button clicks. 
    * 
    * One action so far: 
    * o Update the sales figure for a product 
    */ 
    public void actionPerformed(ActionEvent event) 
    { 
     if (event.getSource() == updateSalesButton) 
      updateSalesAction(); 

     // And refresh the display 
     repaint(); 
    } 

    /** 
    * Action updating a sales figure: the new sales figure is fetched 
    * from a text fields, parsed (converted to an int), and action is taken. 
    */ 
    private void updateSalesAction() 
    { 
     // Fetch the new sales details 
     int productRef = Integer.parseInt(productRefEntryField.getText()); 
     int newSales = Integer.parseInt(productSalesEntryField.getText()); 
     if (productRef>0&&productRef<=MAX_PRODUCTS) 
     { 
      // Update the sales tables 
      productSales[productRef] = newSales; 
      totalSales = totalSales + newSales; 
      percentage[productRef] = calculatePercentage(productSales[productRef-1], totalSales); 
     } 


    } 

    /** 
    * Redraw all the sales data on the given graphics area 
    */ 
    public void paintScreen(Graphics g) 
    { 
     // Draw a table of the sales data, with columns for the product number, 
     // product name, and sales 

     //Heading 
     g.setFont(new Font("default", Font.BOLD, 16)); 
     g.drawString("Product sales data:", 20, 20); 

     // Table column headers 
     g.setFont(new Font("default", Font.BOLD, 12)); 
     g.drawString("No", PRODUCT_X, 60); 
     g.drawString("Name", NAME_X, 60); 
     g.drawString("Sales", SALES_X, 60); 
     g.drawString("Percentage", PERCENTAGE_X, 60); 

     // The table of sales data 
     g.setFont(new Font("default", Font.PLAIN, 12)); 
     int y = 80;// The y coordinate for each line 
     int yIncrement = 20; 

     for(int i = 0; i<productName.length-1; i++) 
     { 
      g.drawString(""+Integer.toString(i+1), PRODUCT_X, y+i*yIncrement);   // First column: product number 

     } 
     for(int i = 0; i<productName.length-1; i++) 
     { 
      g.drawString(productName[i+1], NAME_X, y+i*yIncrement); // Second column: product name 

     } 
     for(int i = 0; i<productSales.length-1; i++) 
     { 
      g.drawString(Integer.toString(productSales[i+1]), SALES_X, y+i*yIncrement); // Third column: sales figure 
     } 
     for(int i = 0; i<percentage.length-1; i++) 
     { 
      g.drawString(Float.toString(percentage[i+1]), PERCENTAGE_X, y+i*yIncrement); 
     } 
     for(int i = 0; i<TABLE_LINES_Y ; i++) 
     { 
      //g.drawLine(
     } 
    } 

    public float calculatePercentage(int sales, int totalSales) 
    { 
     float percentage = sales/totalSales; 
     return percentage;  

    } 
} 

Answer 1

, sizin yüzdelik hesaplama tamsayı bölme muzdarip olan ilk satış eklediğinizde yüzde güncellenmesi değildir. (Daha çok bir yüzdesi benzeyecek şekilde 100 ile çarpın, ayrıca) yüzdesini hesaplamak için kullanın:

public float calculatePercentage(int sales, int totalSales) 
{ 
    return 100.0f * sales/totalSales; 
} 

İkinci, her güncelleme ile ürünlerin tüm döngü gereken tüm böylece Yüzdeler & doğru olacak, böylece totalSales sayısı doğru olacaktır.

private void updateSalesAction() 
{ 
    // Fetch the new sales details 
    int productRef = Integer.parseInt(productRefEntryField.getText()); 
    int newSales = Integer.parseInt(productSalesEntryField.getText()); 
    if (productRef>0&&productRef<=MAX_PRODUCTS) 
    { 
     // Update the sales tables 
     productSales[productRef] = newSales; 
     totalSales = 0; 
     for (int i = 1; i <= MAX_PRODUCTS; i++) 
      totalSales += productSales[i]; 
     for (int i = 1; i <= MAX_PRODUCTS; i++) 
      percentage[i] = calculatePercentage(productSales[i], totalSales); 
    } 
} 

Test ettim ve bu güncellemeler programı düzeltiyor.