在循环错误调用方法

Question

我尝试使用下面的API来调用while循环动画：

public void animate(String currentTransaction, double currentAmount, double currentBalance) 

我想以此来拨打电话：

animate( currentTransaction, currentAmount, currentBalance); 

但是，我不断收到错误。我究竟做错了什么？

的错误是：

currentTransaction cannot be resolved to a variable and 
currentBalance cannot be resolved to a variable 

下面发布是我的代码：

import javax.swing.JOptionPane; 
import java.text.DecimalFormat; 
import javax.swing.JFrame; 
import java.awt.Graphics; 
import java.util.StringTokenizer; 
import java.util.Scanner; 
import java.io.File; 
import java.io.FileReader; 
import java.io.FileWriter; 
import java.io.BufferedWriter; 
import java.io.IOException; 
import java.io.FileNotFoundException; 

public class Accounting extends JFrame { 
private BankAccount bankAccount; 

public Accounting() { 
    bankAccount = new BankAccount(getBackground()); 
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    setSize(300, 300); 
    setVisible(true); 
} 

public void balanceCheckBook() { 
    double balance; 
    double currentAmount; 
    String nextLine; 
    StringTokenizer st; 
    String transactionName; 
    Scanner scan = null; 
    try { 
     scan = new Scanner (new FileReader("transactions.txt")); 
    } catch (FileNotFoundException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
    Scanner callParse; 
    String trans; 
    while (scan.hasNextLine()) { 
     trans = scan.nextLine(); 
     scan.useDelimiter(":"); 
     callParse = new Scanner(trans); 
     callParse.useDelimiter(":"); 
    } 
    try { 
     scan = new Scanner (new FileReader("checkbook.txt")); 
    } catch (FileNotFoundException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
    Scanner callParse2; 
    String check; 
    while (scan.hasNextLine()) { 
     check = scan.nextLine(); 
     scan.useDelimiter(":"); 
     callParse2 = new Scanner(check); 
     callParse2.useDelimiter(":"); 
    } 

    animate( currentTransaction, currentAmount, currentBalance); 
} 

public void animate(String currentTransaction, double currentAmount, double currentBalance) { 
    // set the current transaction in the bankAccount object 
    if (currentTransaction.startsWith("Ch")) 
     bankAccount.setCurrentTransaction(new Check(currentAmount)); 
    else if (currentTransaction.startsWith("With")) 
     bankAccount.setCurrentTransaction(new Withdrawal(currentAmount)); 
    else if (currentTransaction.startsWith("Dep")) 
     bankAccount.setCurrentTransaction(new Deposit(currentAmount)); 
    else 
     bankAccount.setCurrentTransaction(new UnknownTransaction(currentAmount)); 
    // set the currentBalance data member in the bankAccount object 
    bankAccount.updateBalance(currentBalance); 

    repaint(); 
    try { 
     Thread.sleep(3000); // wait for the animation to finish 
    } catch (Exception e) { 
    } 
} 

public void paint(Graphics g) { 
    super.paint(g); 
    bankAccount.draw(g); 
} 

public static void main(String [] args) { 
    Accounting app = new Accounting(); 
    app.balanceCheckBook(); 
} 
} 

Answer 1

变量currentTransaction不会在你的函数balanceCheckBook的范围存在。如果是这种情况，您需要传递一个变量来运行balanceCheckBook或在名为currentTransaction的类中创建一个成员变量。

换句话说，当你与可变currentTransaction未定义调用函数animate在功能balanceCheckBook，编译器将永远不会知道哪个值你要传递给函数animate。

animate( currentTransaction, currentAmount, currentBalance); 

因此，您需要定义currentTransaction并让Java知道要传递什么值。

Answer 2

currentTransaction未在该方法的范围内定义，也不是该方法的参数。您需要可以传递变量作为参数，或使其实例变量。该方法声明为：

public void animate(String currentTransaction, double currentAmount, 
        double currentBalance) 

因此，你需要用String，一个double和另一double叫它：animate(String, double ,double)，而你叫它作为animate( currentTransaction, currentAmount, currentBalance);，但我不知道你在哪里定义了currentTransaction或currentBalance。

Answer 3

对我来说，它看起来像你应该使用变量balance代替currentBalance和trans或transactionName代替currentTransaction。