如果在ActionPerformed事件期间未执行语句

Question

Trying to write a Swing GUI. When clicking a button, I want to test if the other button has already been clicked. If it has, then execute the statements in the "if" statements. But it looks like the "if" statements never execute?

private void radSingleBurgerActionPerformed(java.awt.event.ActionEvent evt) {
    if(radDoubleBurger.isSelected()){
        newItemPrice = Double.parseDouble(lblItemPrice.getText());
        newItemPrice -= doublePrice;
        lblTest.setText(String.valueOf(newItemPrice));//test to see if working
    }
    lblItemPrice.setText(String.valueOf(newItemPrice += singlePrice));
}                                               

private void radDoubleBurgerActionPerformed(java.awt.event.ActionEvent evt) {
     if(radSingleBurger.isSelected()){
        newItemPrice = Double.parseDouble(lblItemPrice.getText());
        newItemPrice -= singlePrice;
        lblTest.setText(String.valueOf(newItemPrice));//test to see if working
    }
    lblItemPrice.setText(String.valueOf(newItemPrice += doublePrice));
}

Answer 1

Clicking a JButton does not make it (permanently) selected. Clicking is only a temporary action.

Maybe you want to use a JToggleButton . This allows you to click a button to make it selected and then click it again to make it unselected.

Read the section from the Swing tutorial on How to Use Buttons for more information.

Or if you just want to know if the user has clicked on a regular JButton , then you will need to maintain a Boolean variable yourself that you update in the ActionListener of the button.