JOptionPane 和读取整数 - 初学者 Java
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JOptionPane and reading integers - Beginner Java
提问by ShiftyMcGrifty
I currently have code that reads the month, date, and year a user enters in one line (separated by spaces). Here is the code.
我目前有读取用户在一行中输入的月份、日期和年份的代码（用空格分隔）。这是代码。
Scanner input = new Scanner(System.in);
int day = 0;
int month = 0;
int year = 0;
System.out.printf("enter the month, date, and year(a 2 numbered year). Put a space between the month, day, and year");
month = input.nextInt();
day = input.nextInt();
year = input.nextInt();
This works fine, the second part is to display a message, if month * day == year, then it is a magical number, if not, then it is not a magical number. It has to be displayed in a dialog box. here is my code for that, and it is working just fine.
这很好用，第二部分是显示一条消息，如果月 * 日 == 年，那么它是一个神奇的数字，如果不是，那么它不是一个神奇的数字。它必须显示在对话框中。这是我的代码，它运行良好。
if((day * month) == year)
{
String message = String.format("%s", "The date you entered is MAGIC!");//If the day * month equals the year, then it is a magic number
JOptionPane.showMessageDialog(null, message);
}
if((day * month) != year)
{
String message = String.format("%s", "The date you entered is NOT MAGIC!");//If the day * month does not equal the year, it is not a magic number
JOptionPane.showMessageDialog(null, message);
}
My question is!! How can I get a dialog box to take the inputs of the month, date, and year in one line the way it works in the console. I'm working in DrJava, and the chapter of the book I'm in doesn't help me with this specific use. Any help would be great. Thanks all!
我的问题是！！如何获得一个对话框以在一行中输入月份、日期和年份的输入，就像它在控制台中的工作方式一样。我在 DrJava 中工作，我所在的这本书的章节对我的这种特定用途没有帮助。任何帮助都会很棒。谢谢大家！
回答by MadProgrammer
There are a number of ways to approach the problem depending on ultimately what it is you want to achieve.
有多种方法可以解决问题，具体取决于您最终要实现的目标。
JOptionPaneallows you to supply Objectas the message. If this message is a Stringit will rendered as is, however, if it is a Componentof some kind, it will be simply added to the dialog. This makes JOptionPanea very powerful little API.
JOptionPane允许您Object作为消息提供。如果此消息是 aString它将按原样呈现，但是，如果它是Component某种类型的，它将被简单地添加到对话框中。这构成JOptionPane了一个非常强大的小 API。
public class TestOptionPane07 {
public static void main(String[] args) {
new TestOptionPane07();
}
public TestOptionPane07() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JTextField fldDay = new JTextField(3);
JTextField fldMonth = new JTextField(3);
JTextField fldYear = new JTextField(4);
JPanel message = new JPanel();
message.add(fldDay);
message.add(new JLabel("/"));
message.add(fldMonth);
message.add(new JLabel("/"));
message.add(fldYear);
int result = JOptionPane.showConfirmDialog(null, message, "Enter Date", JOptionPane.OK_CANCEL_OPTION, JOptionPane.QUESTION_MESSAGE);
if (result == JOptionPane.OK_OPTION) {
String sDay = fldDay.getText();
String sMonth = fldMonth.getText();
String sYear = fldYear.getText();
JOptionPane.showMessageDialog(null, "You enetered " + sDay + "/" + sMonth + "/" + sYear);
try {
int day = Integer.parseInt(sDay);
int month = Integer.parseInt(sMonth);
int year = Integer.parseInt(sYear);
JOptionPane.showMessageDialog(null, "You enetered " + day + "/" + month + "/" + year);
} catch (Exception e) {
JOptionPane.showMessageDialog(null, "The values you entered are invalid");
}
}
}
});
}
}
Updated
更新
If I was going to use something like this, I would also use a DocumentFilterto ensure that the user could only enter valid values (examples here)
如果我打算使用这样的东西，我也会使用DocumentFilter来确保用户只能输入有效值（示例在这里）
But you could also use JSpinners
但你也可以使用 JSpinners
Or JComboBox
或者 JComboBox
Depending on what it is you want to achieve...
取决于你想要达到的目标......
回答by Smit
You can make use of following to take user input
您可以使用以下内容来获取用户输入
String word = JOptionPane.showInputDialog("Enter 3 int values");
String[] vals = word.split("\s+"); // split the sting by whitespaces accepts regex.
// vals[0] cast to int
// convert string representation of number into actual int value
int day = Integer.parseInt(vals[0]); // throws NumberFormatException
// vals[1] cast to int
// vals[2] cast to int
回答by Aaron
Here's some code, everything is described in the comments:
这是一些代码，所有内容都在注释中描述：
// import statements
import javax.swing.JOptionPane;
// main class
public class Main {
// main method
public static void main(String[] args) {
// get info
try {
Info info = new Info();
} catch(Exception e) {
System.err.println("Error! " + e.getMessage());
}
// do whatever with the info
}
// info class
static class Info {
// instance variables
public int day, month, year;
// constructor
public Info() throws Exception {
// get inputs
String[] inputs = JOptionPane.showInputDialog(null,
"Enter day, month, year").split(" ");
// not the right size
if(inputs.length != 3) {
throw new Exception("Not enough infomation was given!");
}
// get values
day = Integer.parseInt(inputs[0]);
month = Integer.parseInt(inputs[1]);
year = Integer.parseInt(inputs[2]);
}
}
}
It has an elegant way of notifying you if something went wrong, and everything you need is packaged up in a convenient object.
如果出现问题，它有一种优雅的方式通知您，您需要的一切都打包在一个方便的对象中。
