java final 赋值_无法为java中的" final" 变量赋值 (cannot assign value to "final" variable in java)...

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#java final 赋值

在Java编程中，遇到一个关于final变量的问题。在事件监听器中尝试将`JTextField`的输入值赋给声明为final的变量`c`时，出现错误提示。如果去掉final关键字，又会导致局部变量不能在匿名内部类中访问。这个问题涉及到Java中final变量的作用域和使用规则。解决方案可能涉及到理解final变量如何在匿名内部类中使用。

2012-04-16 12:27:15

private void pushButtonActionPerformed(java.awt.event.ActionEvent evt)

{

final int c=0;

final JDialog d=new JDialog();

JLabel l=new JLabel("Enter the Element :");

JButton but1=new JButton("OK");

JButton but2=new JButton("Cancel");

final JTextField f=new JTextField(10);

JPanel panel = new JPanel();

but1.addActionListener(new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

c=Integer.parseInt(f.getText());

d.setVisible(false);

d.dispose( );

}

});

but2.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent e){

d.setVisible(false);

d.dispose( );

}

});

}

I am using netbeans 7.1.1. This is my code here i have declared 'c' as "final int" but the line "c=Integer.parseInt(f.getText());" i am getting an error "cannot assign a value to a final variable". If i am deleting the word final from the declaration and making it just as "int c" then in the same line i get an error "local variable c cannot be accessed from within a class;needs to be declared final". can anyone tell me why is this happening ?