Java 如何检查按钮组中是否选择了单选按钮?
我有一个由5个单选按钮组成的按钮组,我需要检查是否至少选择了其中一个 是这样吗Java 如何检查按钮组中是否选择了单选按钮?,java,swing,netbeans-7,Java,Swing,Netbeans 7,我有一个由5个单选按钮组成的按钮组,我需要检查是否至少选择了其中一个 是这样吗 buttonGroup1.isSelected(ButtonModel) 但是这里的按钮模型是什么?package radiobuttongroup; package radiobuttongroup; import java.awt.Container; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.e
buttonGroup1.isSelected(ButtonModel)代码>
但是这里的按钮模型是什么?package radiobuttongroup;
package radiobuttongroup;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.LinkedHashMap;
import java.util.Map;
import javax.swing.ButtonGroup;
import javax.swing.ButtonModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JRadioButton;
public class RadioButtonGroup {
public static void main(String[] args) {
new RadioButtonGroup();
}
private RadioButtonGroup() {
Container contentPane = frame.getContentPane();
contentPane.setLayout(new GridLayout(0, 1));
for (int i = 1; i <= 5; i++) {
JRadioButton radio = new JRadioButton(Integer.toString(i));
ButtonModel buttonModel = radio.getModel();
modelToRadioButton.put(buttonModel, radio);
buttonGroup.add(radio);
contentPane.add(radio);
}
JButton buttonTestSelection = new JButton("Selection Test");
JButton buttonClearSelection = new JButton("Clear Selection");
contentPane.add(buttonTestSelection);
contentPane.add(buttonClearSelection);
buttonTestSelection.addActionListener(new ActionListener() {
@Override public void actionPerformed(ActionEvent arg0) {
ButtonModel buttonModel = buttonGroup.getSelection();
if (buttonModel == null) {
System.out.println("No radio button is selected");
}
else {
if (modelToRadioButton.containsKey(buttonModel)) {
JRadioButton b = modelToRadioButton.get(buttonModel);
System.out.println("You selected button " + b.getText());
}
else {
System.err.println("Weird, unrecognised button model!");
}
}
}
});
buttonClearSelection.addActionListener(new ActionListener() {
@Override public void actionPerformed(ActionEvent e) {
buttonGroup.clearSelection();
}
});
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private JFrame frame = new JFrame("RadioButtonGroup");
private Map<ButtonModel, JRadioButton> modelToRadioButton =
new LinkedHashMap<ButtonModel, JRadioButton>();
private ButtonGroup buttonGroup = new ButtonGroup();
}
导入java.awt.Container;
导入java.awt.GridLayout;
导入java.awt.event.ActionEvent;
导入java.awt.event.ActionListener;
导入java.util.LinkedHashMap;
导入java.util.Map;
导入javax.swing.ButtonGroup;
导入javax.swing.ButtonModel;
导入javax.swing.JButton;
导入javax.swing.JFrame;
导入javax.swing.JRadioButton;
公共类RadioButtonGroup{
公共静态void main(字符串[]args){
新的RadioButtonGroup();
}
专用RadioButtonGroup(){
容器contentPane=frame.getContentPane();
setLayout(新的GridLayout(0,1));
对于(int i=1;i,因为您只有5个单选按钮,所以可以手动检查所有按钮
(假设单选按钮命名为radio1,…,radio5):
这不是最优雅的解决方案,但它可以解决问题。在查找所选单选按钮时,使用ButtonModel做不了多少事情。但是ButtonGroup确实有getElements()方法返回AbstractButtons的枚举。这些AbstractButtons可以在通过枚举的迭代过程中转换为JRadioButtons
buttonGroup1.getSelection()==null
下面的方法将返回传递给它的ButtonGroup的所选JRadioButton,如果未选择,则返回null
private JRadioButton getSelectedRadioButton(ButtonGroup buttonGroup) {
Enumeration<AbstractButton> abstractButtons = buttonGroup.getElements();
JRadioButton radioButton = null;
while (abstractButtons.hasMoreElements()) {
radioButton = (JRadioButton) abstractButtons.nextElement();
if (radioButton.isSelected()) {
break;
}
}
return radioButton;
}
String selectedRadioButtonText = getSelectedRadioButton(buttonGroup).getText();
我希望这对某人有所帮助!!!此外,更重要的是,您可以使用ButtonGroup类的getSelected()方法确定按钮组的单选按钮中是否有选择,因为如果没有选择,则返回null
private boolean isSelection(ButtonGroup buttonGroup) {
return (buttonGroup.getSelected() != null);
}
我希望这对某人有帮助!!!嗯..与a相比没有什么新的,是吗?
private boolean isSelection(ButtonGroup buttonGroup) {
return (buttonGroup.getSelected() != null);
}