Java编程出现问题了求解

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;
import javax.swing.text.JTextComponent;

public class Calculator1 extends JFrame implements ActionListener{

public Calculator1(){
       setTitle("简单计算器");
        init();
        setBounds(100,100,280,280);
        setVisible(true);

       }
       void init(){
        JTextField show=new JTextField();
        show.setPreferredSize(new Dimension(12,50));
        GridLayout grid=new GridLayout(4,4);
        show.setText("0");
        show.setHorizontalAlignment(JTextField.RIGHT);
        grid.setHgap(5);
        grid.setVgap(5);
        JPanel panel=new JPanel();
        panel.setLayout(grid);
        this.getContentPane().add(panel,BorderLayout.CENTER);
        this.getContentPane().add(show,BorderLayout.NORTH);
        this.getContentPane().add(new JButton("清除"),BorderLayout.SOUTH);
        String name[]={"1","2","3","+","4","5","6","—","7","8","9","x",".","0","=","÷"};
        JButton []button=new JButton[16];
        for(int i=0;i<name.length;i++){
        button[i]= new JButton(name[i]);
        panel.add(button[i]);
        button[i].addActionListener(this);
        }
        show.addActionListener(this);
       }

String num="0123456789";
String str="清除,x,÷,+,-";
double num1=0,num2=0,result=0;
char ch;
boolean isfirst=true;

public void actionPerformed(ActionEvent e) {
String get=e.getActionCommand();
if(isfirst&&num.indexOf(get)!=-1){
isfirst=false;
show.setText=("");

}
}
}
本人菜鸟一枚，编计算器的时候编到我写的最后一步的时候编译器说Multiple markers at this line
- setText cannot be resolved or is not
a field
- show cannot be resolved to a
variable
什么意思  show不是在前面定义了么。 --------------------编程问答-------------------- show.setText=("");
改为show.setText(""); --------------------编程问答-------------------- - -坑爹了，这个简单问题都没看出来 --------------------编程问答-------------------- 弱弱的问一句这个show文本框需要添加监视器么？？
--------------------编程问答-------------------- show 是init方法的局部变量

在actionPerformed里不能使用

补充：Java ,  Java相关

Java编程出现问题了 求解

Java编程出现问题了求解