catalogue

Four message prompt box methods commonly used by JOptionPane class

Parameters of the JOptionPane class

showMessageDialog()；

showConfirmDialog();

showOptionDialog();

showInputDialog();

Four message prompt box methods commonly used by JOptionPane class

showMessageDialog();	Message dialog box
showConfirmDialog();	Option Dialog
showOptionDialog();	Custom selection dialog box
showInputDialog();	Input Dialog

Introduction to parameters of JOptionPane class

Introduction to JOptionPane parameter

parentComponent	Parent container (component) of settings dialog box
message	Message content
title	Dialog Title
messageType	Message type. Each message type provides a default image
icon	Sets the image of the custom dialog box
optionType	Button type
options	Custom button array, custom option button text
initalValue	Sets the default selected button
selectionValues	Custom options array, used to define drop-down boxes
initialselectionValue	Sets the default selected option

parentComponent: the dialog box will be displayed in the center of the container. If null is not specified and passed in, the default Frame will be used as the parent window of the dialog box, that is, the dialog box will be displayed in the center of the screen

showMessageDialog()；

Parameter format:

JOptionPane.showMessageDialog(parentComponent, message, title, messageType, icon);

1. Text box

JOptionPane.showMessageDialog(null,"Basic box","Title",JOptionPane.PLAIN_MESSAGE);

2. General prompt box

JOptionPane.showMessageDialog(null,"General prompt box");
JOptionPane.showMessageDialog(null,"General prompt box","Title",JOptionPane.INFORMATION_MESSAGE);

From the execution results of the above two codes, we can know that the default value of messageType is joptionpane.information_ The default value of message and title is "message"

This method can be used when you want to prompt the information of the dynamic array

  3. Warning box

JOptionPane.showMessageDialog(null,"Warning box","Title",JOptionPane.WARNING_MESSAGE);

4. Error prompt box

JOptionPane.showMessageDialog(null,"Error prompt box","Title",JOptionPane.ERROR_MESSAGE);

5. Question box (question box)

JOptionPane.showMessageDialog(null,"Question box","Title",JOptionPane.QUESTION_MESSAGE);

showConfirmDialog();

Select the dialog box to set the buttons of the dialog box. Usually, the buttons are a combination of yes, no, OK and cancel

Parameter format:

JOptionPane.showConfirmDialog(parentComponent, message, title, optionType, messageType, icon)

1. Dialog box

int n = JOptionPane.showConfirmDialog(null,"Do you like it java？","Title",JOptionPane.YES_NO_CANCEL_OPTION);
System.out.println(n);

        

Through the test, we can find that the return value of this method is int type. Select the first button to return 0, the second button to return 1, and so on

showOptionDialog();

Parameter format:

JOptionPane.showOptionDialog(parentComponent, message, title, optionType, messageType, icon, options, initialValue)

Object[] options = {"like", "dislike"};        //Defines the text on the button
int n = JOptionPane.showOptionDialog(null,"do you like me?","Title",JOptionPane.YES_NO_OPTION,JOptionPane.QUESTION_MESSAGE,null,options,options);

Object[] options = {"like", "dislike"};        //Defines the text on the button
int n = JOptionPane.showOptionDialog(null,"do you like me?","Title",JOptionPane.YES_NO_OPTION,JOptionPane.QUESTION_MESSAGE,null,options,options[1]);

 

The first option is the name of the custom Object array, and the last option is the specified default option. If the subscript is not specified, it is equivalent to selecting the first option options[0]

showInputDialog();

Parameter format:

JOptionPane.showInputDialog(parentComponent, message, title, messageType, icon, selectionValues, initialSelectionValue)

1. Input box

String name = JOptionPane.showInputDialog(null,"Please enter your account\n","Title",JOptionPane.PLAIN_MESSAGE);
System.out.println(name);

The return value type is String

2. Drop down box

Object[] options = {"China", "U.S.A","Germany",4};        //Define drop-down box options. When the array length is greater than or equal to 20, it will become a list box
Object object =  JOptionPane.showInputDialog(null,"Please choose your nationality\n","Title",JOptionPane.QUESTION_MESSAGE,new ImageIcon("D://Earth. png"), options," China ");
System.out.println(object);
System.out.println(object instanceof String);

Note here: why should the return value type be received with a variable of type Object?

Because this method returns the contents of the drop-down box you selected, it is received by applying the Object type. When "4" is selected, the return value type is int, and when "China" is selected, the return value type is String

3. List box

Object[] options = {"China", "U.S.A","Germany",4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20};        //Define drop-down box options. When the array length is greater than or equal to 20, it will become a list box
Object object =  JOptionPane.showInputDialog(null,"Please choose your nationality\n","Title",JOptionPane.QUESTION_MESSAGE,new ImageIcon("D://Earth. png"),options," China ");
System.out.println(object instanceof String);

When the length of the options array exceeds 20, the dialog box will be presented as a list box