如何處理JOptionPane中的取消按鈕

Question

我創建了一個JOptionPane類型爲showInputDialog。當它打開它時，會顯示兩個按鈕：確定和取消。我想處理這個動作時，我推動取消按鈕，但我不知道如何達到它。我怎麼才能得到它？

Answer 1

例如：

int n = JOptionPane.showConfirmDialog(
          frame, "Would you like green eggs and ham?", 
          "An Inane Question", 
          JOptionPane.YES_NO_OPTION); 
if (n == JOptionPane.YES_OPTION) { 

} else if (n == JOptionPane.NO_OPTION) { 

} else { 

} 

可選地與showOptionDialog：

Object[] options = {"Yes, please", "No way!"}; 
int n = JOptionPane.showOptionDialog(frame, 
       "Would you like green eggs and ham?", 
       "A Silly Question", 
       JOptionPane.YES_NO_OPTION, 
       JOptionPane.QUESTION_MESSAGE, 
       null, 
       options, 
       options[0]); 
if (n == JOptionPane.YES_OPTION) { 

} else if (n == JOptionPane.NO_OPTION) { 

} else { 

} 

詳情請參閱How to Make Dialogs。

編輯：showInputDialog

String response = JOptionPane.showInputDialog(owner, "Input:", ""); 
if ((response != null) && (response.length() > 0)) { 

} 

Answer 2

showMessageDialog不應該顯示兩個按鈕，所以某些東西與您的代碼或您的解釋有關。無論如何，如果你想給用戶一個選擇並且想要檢測這個選擇，不要使用showMessageDialog而是使用showConfirmDialog，並且返回int並測試它是否是JOptoinPane.OK_OPTION。

Answer 3

這是一個老問題了，我是一個Java的新手，所以有可能是更好的解決方案，但我想知道同樣的，也許它可以幫助別人，我確實是檢查響應是否爲空。

這爲我工作：

//inputdialog 
    JOptionPane inpOption = new JOptionPane(); 

    //Shows a inputdialog 
    String strDialogResponse = inpOption.showInputDialog("Enter a number: "); 

    //if OK is pushed then (if not strDialogResponse is null) 
    if (strDialogResponse != null){ 

     (Code to do something if the user push OK) 

    } 
    //If cancel button is pressed 
    else{ 

     (Code to do something if the user push Cancel) 

    } 

Answer 4

這可能是你的答案：

package Joptionpane; 

import javax.swing.JOptionPane; 

public class Cancle_on_JOptionPane { 

    public static void main(String[] args) { 
     String s; 
     int i; 
     for(i=0;i<100;i++){ 
     s = JOptionPane.showInputDialog(null,"What is your favorite fruit ?"); 
         try{ 
           if(s.equals("")) { 
                  JOptionPane.showMessageDialog(null," Enter your answer !!!"," ^-^ Information^-^ ",JOptionPane.INFORMATION_MESSAGE); 
                  i=2; 
                 } 
           else { 
              JOptionPane.showMessageDialog(null," s = "+s," ^-^ Information^-^ ",JOptionPane.INFORMATION_MESSAGE); 
              i=100; 
             } 
          } 
     catch(Exception e) 
       { 
       JOptionPane.showMessageDialog(null,"Cancle answer !!!"," ^-^ Information^-^ ",JOptionPane.INFORMATION_MESSAGE); 
       i=100; 
       } 
    } 
    } 
} 

Answer 5

package Joptionpane; 

import javax.swing.JOptionPane; 

public class Cancle_on_JOptionPane { 

    public static void main(String[] args) { 
     String s; 
     int i; 
     for (i=0;i<100;i++){ 
      s = JOptionPane.showInputDialog(null,"What is your favorite fruit ?"); 
      try { 
       if (s.equals("")) { 
        JOptionPane.showMessageDialog(null," Enter your answer !!!"," ^-^ Information^-^ ",JOptionPane.INFORMATION_MESSAGE); 
        i=2; 
       } else { 
        JOptionPane.showMessageDialog(null," s = "+s," ^-^ Information^-^ ",JOptionPane.INFORMATION_MESSAGE); 
        i=100; 
       } 
      } 
      catch (Exception e) { 
       JOptionPane.showMessageDialog(null,"Cancle answer !!!"," ^-^ Information^-^ ",JOptionPane.INFORMATION_MESSAGE); 
       i=100; 
      } 
     } 
    } 
}