按下回车键时，JFrame中的默认按钮不会触发 [英] Default button in JFrame is not firing when the enter key is being pressed

问题描述

我有一个 JFrame ，上面有三个JButton。我已设置 txtSearch （一个 JTextField 组件）以便在 JFrame 加载。其中一个按钮被设置为默认按钮。这是我的代码：

I have a JFrame with three JButtons on it. I have set txtSearch (a JTextField component) to have the focus when JFrame loads. One of the buttons is set as the default button. This is my code:

private void formWindowOpened(java.awt.event.WindowEvent evt) 
{
     // btnRefresh.setMnemonic(KeyEvent.VK_R); // Even if this line 
                                               // is not commented, but
                                               // still the event wouldn't fire.
     this.getRootPane().setDefaultButton(btnRefresh);
}

加载时，按钮刚刚被选中，但是当它按下时什么也没做正在按 Enter 键。我如何正确实现它？

When it loads, the button is just selected, but it did nothing when the Enter key was being pressed. How do I correctly implement it?

btnRefresh.addActionListener(new java.awt.event.ActionListener() {
    public void actionPerformed(java.awt.event.ActionEvent evt) {
        btnRefreshActionPerformed(evt);
    }
});

private void btnRefreshActionPerformed(java.awt.event.ActionEvent evt) {                                           
    JOptionPane.showMessageDialog(this, "Pressed!");
    // Other codes here (Replace by JOptionPane)
}  

推荐答案

当 JFrame 出现时，哪个组件有焦点？我问，因为一些组件吃掉Enter键事件。例如， JEditorPane 会这样做。

What component has focus when the JFrame comes up? I ask because some components "eat" the Enter key event. For example, a JEditorPane will do that.

此外，当您指定 ActionListener时到 JTextField ，将调用 ActionListener 而不是根窗格的DefaultButton 。您必须选择具有 ActionListener 或 DefaultButton ，但是您不能同时使用的JTextField 。我确信这也适用于其他组件。

Also, when you assign an ActionListener to JTextField, the ActionListener will be called instead of the DefaultButton for the root pane. You must choose either to have an ActionListener or a DefaultButton, but you can't have both fire for the same JTextField. I'm sure this applies to other components as well.

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