java 如何使用 JButton 从 JTextField 获取 int
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how to get int from JTextField with a JButton
提问by ChildProdigy
I'm trying to get an int from my JTextField with the click of my JButton but I can't figure out how to do so. I'm trying to get the int and set it to a variable so I can use it in my program further down.
我试图通过单击我的 JButton 从我的 JTextField 获取一个 int，但我不知道如何做到这一点。我正在尝试获取 int 并将其设置为一个变量，以便我可以在我的程序中进一步使用它。
Here is the code(this is the whole method):
这是代码（这是整个方法）：
JFrame presets = new JFrame("Presets");
presets.setVisible(true);
presets.setSize(500, 500);
JPanel gui = new JPanel(new BorderLayout(2,2));
JPanel labelFields = new JPanel(new BorderLayout(2,2));
labelFields.setBorder(new TitledBorder("Presets"));
JPanel labels = new JPanel(new GridLayout(0,1,1,1));
JPanel fields = new JPanel(new GridLayout(0,1,1,1));
labels.add(new JLabel("Place values on Cat.2/Cat.3 at"));
JTextField f1 = new JTextField(10);
String text = f1.getText();
int first = Integer.parseInt(text);
labels.add(new JLabel("and place follow up value at"));
fields.add(new JTextField(10));
labelFields.add(labels, BorderLayout.CENTER);
labelFields.add(fields, BorderLayout.EAST);
JPanel guiCenter = new JPanel(new BorderLayout(2,2));
JPanel submit = new JPanel(new FlowLayout(FlowLayout.CENTER));
submit.add( new JButton("Submit") );
guiCenter.add( submit, BorderLayout.NORTH );
gui.add(labelFields, BorderLayout.NORTH);
gui.add(guiCenter, BorderLayout.CENTER);
JOptionPane.showMessageDialog(null, gui);
回答by newuser
Try this,
试试这个，
String getText()
Returns the text contained in this TextComponent.
So, convert your String to Integer as:
因此，将您的 String 转换为 Integer 为：
try {
int integerValue = Integer.parseInt(jTextField.getText());
}
catch(NumberFormatException ex)
{
System.out.println("Exception : "+ex);
}
回答by Paniz
if you want to get the f1 text when the submit pressed, use this code:
如果您想在按下提交时获取 f1 文本，请使用以下代码：
.
.
.
JPanel submit = new JPanel(new FlowLayout(FlowLayout.CENTER));
JButton button = new JButton("Submit");
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
int first = Integer.parseInt(f1.getText().trim());
}
});
submit.add(button);
guiCenter.add(submit, BorderLayout.NORTH);
.
.
.
回答by a question
Probably you want the entered data as int. write it in the button action
可能您希望输入的数据为int. 把它写在按钮动作中
JButton button = new JButton("Submit");
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
try {
int myInt=Integer.parseInt(jtextfield.getText());
System.out.println("Integer is: "+myInt);
//do some stuff
}
catch (NumberFormatException ex) {
System.out.println("Not a number");
//do you want
}
}
});
Remember Integer.parseIntthrows NumberFormatExceptionwhich must be caught. see java docs
记住必须抓住的Integer.parseInt投掷NumberFormatException。请参阅Java 文档
