禁用Java中的按钮，直到所有字段都填满 [英] Disable button in Java until all fields filled

问题描述

我是Java的新手，正在开发一个小项目.我正在编写一个程序，其中用户必须自己注册.我的选项卡式窗格中有3个不同的选项卡.我希望能够第一个窗格上的禁用 下一个按钮，使用户无法<除非窗格1上的所有 text 字段均已填充，否则strong>继续继续到窗格2.我一直在网上搜索，发现了各种示例，但它们都无法在运行时正常工作.

I'm new to Java and developing a small project. I'm making a program where the user has to register themselves. I have 3 different tabs on my Tabbed Pane. I want to be able to disable the next button on the first pane making it impossible for the user to continue to pane 2 unless all the text fields on pane 1 have been filled. I have been Searching online and found various examples but none of them would work in run time.

我正在使用Netbeans.

I am using Netbeans.

  private void txtFirstNameActionPerformed(java.awt.event.ActionEvent evt) {                                             

    if(txtFirstName.getText().trim().length() > 0)

        btnNext1.setEnabled(true);
    else 
        btnNext1.setEnabled(false); 
  }

推荐答案

为窗格上所有文本字段创建一个 List :

Create a List of all the text fields on your pane:

List<JTextField> list = new ArrayList<>();

将所有文本字段添加到该列表.

Add all your text fields to that list.

然后，创建一个通用的 DocumentListener 来侦听文本更改事件，并且每次发生文本更新时，请扫描所有文本字段以查看是否已全部填充:

Then, create a universal DocumentListener that listens for text change events, and every time a text update happens, scan through all your text fields to see if they have all been filled:

DocumentListener listener = new DocumentListener() {
    @Override
    public void removeUpdate(DocumentEvent e) { changedUpdate(e); }
    @Override
    public void insertUpdate(DocumentEvent e) { changedUpdate(e); }

    @Override
    public void changedUpdate(DocumentEvent e) {
        boolean canEnable = true;
        for (JTextField tf : list) {
            if (tf.getText().isEmpty()) {
                canEnable = false;
            }
        }
        btnNext1.setEnabled(canEnable);
    }
};

并将该 listener 添加到列表中您拥有的每个文本字段中:

And add that listener to every text field you have in the list:

for (JTextField tf : list) {
    tf.getDocument().addDocumentListener(piecesListener);
}

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