消失的GUI java
我试着让我的GUI工作它是一个下拉菜单 前两个选项有效,但第二个选项无效消失的GUI java,java,swing,user-interface,Java,Swing,User Interface,我试着让我的GUI工作它是一个下拉菜单 前两个选项有效,但第二个选项无效 import java.io.*; import java.lang.*; import java.util.*; import javax.swing.*; public class starter { public static void main (String [] args) { Object[] menuI
import java.io.*;
import java.lang.*;
import java.util.*;
import javax.swing.*;
public class starter
{
public static void main (String [] args)
{
Object[] menuItems1 = {"Login as Admin", "Login as Course Leader", "Login as Lecturer", "Login as Student", "Quit"};
Object selectedValue1 = JOptionPane.showInputDialog(null,"Choose one",
"Input", 2, null, menuItems1, menuItems1[0]);
boolean continuePlaying = true;
if (selectedValue1 == null || selectedValue1.equals("Quit"))
continuePlaying = false;
else if (selectedValue1 == null || selectedValue1.equals("Login as Admin"))
{
//this works
adminMenu a = new adminMenu();
a.adminMenu();
}
else if (selectedValue1.equals("Login as Course Leader"))
{
//and this works
courseLeaderMenu b = new courseLeaderMenu();
b.courseLeaderMenu();
}
else if (selectedValue1.equals("Login as Lecturer"))
{
//but this and
lecturerMenu c = new lecturerMenu();
c.lecturerMenu();
}
else if (selectedValue1.equals("Login as Student"))
{
// this don't
studentMenu d = new studentMenu();
d.studentMenu();
}
}
}
任何帮助都是值得的,这些菜单选项将引入其他的菜单选项,显然使用了我在这里调用的不同类。。。所有内容都可以完美编译,但最后两个选项没有显示任何内容此if语句的字符串中有两个空格
else if (selectedValue1.equals("Login as Lecturer"))
在这一行的“以学生身份登录”字符串中
Object[] menuItems1 = {"Login as Admin", "Login as Course Leader", "Login as Lecturer", "Login as Student", "Quit"};
谢谢开车把我逼疯了,我没看见@user3029733最好直接将所选值与数组中的值进行比较,这样可以防止这些类型的错误