消失GUI的Java

Question

林試着讓我的GUI工作的一個下拉菜單

第2個選項工作，但那麼第二個2不...

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(); 
      } 
     } 
    } 

任何幫助將是appriciated，這些菜單選項會導致其他顯然使用我在這裏稱爲不同的類...其他一切都完美編譯，但最後2個選項不顯示任何東西

Answer 1

你有雙字符串從這個if語句

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

並在該行的「登錄爲學生」串

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