好吧，我想弄清楚当在 GUI 中单击某个按钮时如何将文本添加到 TextArea 中。对于当前的问题，当我单击重置按钮时，我希望它显示我已经预先编写的几行文本。我不确定如何将其实现到我的小程序中。
这是我的按钮代码
public class DisplayButtonPanel2 extends JPanel{
//create buttons for reseting back to original data, displaying data and sorting data
JButton resebutton = new JButton("RESET");
JButton displaybutton = new JButton("DISPLAY");
JButton sortbutton = new JButton("SORT");
//constructor
public DisplayButtonPanel2()
{
//create action listener object
BListen listener = new BListen();
//add action listen functionalty to buttons
resebutton.addActionListener(listener);
displaybutton.addActionListener(listener);
sortbutton.addActionListener(listener);
//add buttons to panel
add(resebutton);
add(displaybutton);
add(sortbutton);
}
public class BListen implements ActionListener
{
public void actionPerformed(ActionEvent event){
if (event.getSource() == resebutton){
JOptionPane.showMessageDialog(null,"reset Button Clicked");
DisplayEmployeePanel displayemply = new DisplayEmployeePanel();
displayemply.resetText();
}
else if(event.getSource() == displaybutton){
JOptionPane.showMessageDialog(null,"display Button Clicked");
// DisplayEmployeePanel displayemply = new DisplayEmployeePanel();
}
else if(event.getSource() == sortbutton){
JOptionPane.showMessageDialog(null,"sort Button Clicked");
}
}
}
文本区域的代码
public class DisplayEmployeePanel extends JPanel{
//create a text area that will display employees
JTextArea employeetextarea = new JTextArea("~Company Employee's~", 20 ,30); //textinarea, hieght, width
//constructor
public DisplayEmployeePanel()
{
employeetextarea.setEditable(false); //will not be able to edit text in area
String ns = "\nDisplay Employee Info BELOW";
employeetextarea.append(ns);
//add text area to panel
add(employeetextarea);
}
public void resetText()
{
String sn = "\nreset to original emmployee list";
employeetextarea.append(sn);
add(employeetextarea);
System.out.println("reset text");///testing purposes
}
}//end class
编辑*如果有帮助的话添加更多源代码， 此代码用于创建框架
public class CreateCompanyGUI extends JFrame{
//constructor
public CreateCompanyGUI()
{
super("Company Applet!"); //tittle
setSize(800,800); //set size *careful when using pack*
setLocationRelativeTo(null); //places frame in middle of screen by default
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //how to close
setLayout(new BorderLayout()); //set BorderLayout manager for this frame
//create panels
DisplayEmployeePanel dep = new DisplayEmployeePanel();
// DisplayEmployeePanel2 dep2 = new DisplayEmployeePanel2();
DisplayButtonPanel dbp = new DisplayButtonPanel();
DisplayButtonPanel2 dbp2 = new DisplayButtonPanel2();
// DisplayListPanel dlp = new DisplayListPanel();
//add panels to frame
add(dep, BorderLayout.NORTH);
add(dbp2, BorderLayout.CENTER);
add(dbp, BorderLayout.SOUTH);
// add(dlp, BorderLayout.EAST);
// add(dep2, BorderLayout.CENTER);
//pack (packs the window and creates appporiate size
pack();
//visible = TRUE (so we can see the frame)
setVisible(true);
}
}//end class
创建GUI的代码
public class CompanyApplet extends JApplet{
public static void main(String[] args)
{
//create GUI for company applet
new CreateCompanyGUI();
}
}
最佳答案
DisplayEmployeePanel displayemply = new DisplayEmployeePanel();
displayemply.resetText();
您不能继续创建新的 DisplayEmployeePanel。您想要更新 GUI 上可见的现有面板的文本区域。那么意味着 DisplayButtonPanel2 需要对 DisplayEmployeePanel 的引用。
因此，在创建两个面板并将它们添加到框架的代码中，您需要将 DisplayEmployeedPanel 作为参数传递给 DisplayButtonPanel2。
或者更简单的解决方案是只使用一个类来创建两个面板。然后该类中的所有方法都可以访问该类中定义的所有组件。
关于java - 单击按钮时将文本添加到 JTextArea 框？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34244535/