Question

我正在尝试使用Java创建一个Calculator应用程序。现在，我正在创建包含所有按钮和Panel的窗口，以显示单击的数字。不知何故，我添加到框架的面板不会显示。任何人都可以帮助我。我在做什么错误？

package com.wells.eda;
import java.awt.*;
public class Calc {
    public static void main(String[] args) {
    Calculator c = new Calculator();

    try{
        Frame fm= c.NewFrame("Calculator",330,310);
        c.NewButton(fm, "1",10,110);
        c.NewButton(fm, "2",90,110);
        c.NewButton(fm, "3",170,110);
        c.NewButton(fm, "4",10,160);
        c.NewButton(fm, "5",90,160);
        c.NewButton(fm, "6",170,160);
        c.NewButton(fm, "7",10,210);
        c.NewButton(fm, "8",90,210);
        c.NewButton(fm, "9",170,210);
        c.NewButton(fm, "00",10,260);
        c.NewButton(fm, "0",90,260);
        c.NewButton(fm, "Reserved",170,260);
        c.NewButton(fm, "+",250,110);
        c.NewButton(fm, "-",250,160);
        c.NewButton(fm, "*",250,210);
        c.NewButton(fm, "/",250,260);
        c.NewPanel(fm);
        //Thread.sleep(3000);
        //fm.dispose();

        }
    catch(Exception e)
        {
        System.out.println("Exception happened");
        }
    }

}
class Calculator{

    public Frame NewFrame(String name,int length, int width) 
    {
        Frame fm = new Frame(name);
        fm.setLayout(null);
        fm.setResizable(false);
        fm.setSize(length,width);
        fm.setVisible(true);
        return(fm);
    }
    public void NewButton(Frame fm,String number,int xcordinate,int ycordinate) throws Exception
    {
        Button b = new Button (number);
        b.setBounds(xcordinate,ycordinate,70,40);
        //b.setVisible(true);
        fm.add(b);          
    }
    public void NewPanel(Frame fm)
    {
        Panel p= new Panel(null);
        fm.add(p);
        //p.setSize(100, 100);
        p.setBounds(10,10,250,100);
        p.setName("Panel");
        p.setVisible(true);
    }

}

Answer 1

您的面板未显示，因为它是空的，并且您没有设置可以使其可见的特定布局。

例如：fm.setLayout（null）; ==＆GT; fm.setLayout（new BorderLayout（））;

public void NewPanel(Frame fm)
{
    Panel p= new Panel(null);
    fm.add(p);
    //p.setSize(100, 100);
    p.setBounds(10,10,250,100);
    p.setName("Panel");
    p.setVisible(true);
}

试试这个：

public void NewPanel(Frame fm)
{
    Panel p= new Panel(null);
    fm.add(p);
    //p.setSize(100, 100);
    p.setBounds(10,10,250,100);
    p.setName("Panel");
    p.add(new JLabel("Test"));
    p.setVisible(true);
}

您将看到您的Panel围绕创建的JLabel

面板在Java框架中不可见

1 个答案: