消失的GUI java

Question

我試着讓我的GUI工作它的下拉菜單

前兩個選項有效，但后兩個選項沒有......

    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();
            }
        }
    }

任何幫助都會得到滿足，這些菜單選項會導致其他顯然使用我在這里調用的不同類...其他所有編譯完美但最后2個選項不顯示任何內容

Answer 1

這個if語句在字符串中有兩個空格

else if (selectedValue1.equals("Login as  Lecturer"))

並在此行的“Login as Student”字符串中

Object[] menuItems1 = {"Login as Admin", "Login as Course Leader", "Login as Lecturer", "Login as  Student", "Quit"};