java 文本区域运行不出来只有窗口

java 文本区域运行不出来只有窗口


```java
package study07;
import java.awt.*;
import javax.swing.*;
public class TextAreaTest  extends JFrame{
    JPanel panelobj;
    JTextArea textareaobj;
    public TextAreaTest()
    {
        super("文本区域测试程序");
        setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
        setVisible(true);
        setSize(240,150);
        panelobj =new JPanel();
        getContentPane().add(panelobj);
        textareaobj.add(textareaobj);
        textareaobj = new JTextArea("文本区域",5,20);
        panelobj.add(textareaobj);
    }
    public static void main(String args[])
    {
        TextAreaTest ta =new TextAreaTest();
        ta.show();
    }

}



![img](https://img-mid.csdnimg.cn/release/static/image/mid/ask/202414314486198.png "#left")


```