无法让 requestFocus 按顺序关注 JTextField答案

【问题标题】：Can't get requestFocus to focus on JTextFields sequentially无法让 requestFocus 按顺序关注 JTextField
【发布时间】：2014-04-09 11:36:42
【问题描述】：

我一直在努力做到这一点，以便在单击 "Next" 按钮时，它会根据需要进入下一个 JTextField，然后是下一个，然后是下一个，依此类推。它只与一个requestFocus() 一起工作，但是当i 将该代码添加到我的每个JTextFields 时，它直接转到了请求的最后一个焦点。代码如下：

//adds functionality to the next button
        next.addActionListener( new ActionListener(){
    @Override
    public void actionPerformed(ActionEvent e){
        //creates a file for the next button output
        final File file = new File("NextOutput.txt");
        //creates a printwriter to output to file everytime next button is clicked (overwrite)
        try (PrintWriter output = new PrintWriter(new FileWriter(file))) {
            String s = fName.getText();
            output.print(s + " ");
            lName.requestFocus();
            String s1 = lName.getText();
            output.append(s1 + " ");
            sNumber.requestFocus();
            String s2 = sNumber.getText();
            output.append(s2 + " ");
            lResults.requestFocus();
            String s3 = lResults.getText();
            output.append(s3 + " ");


        } catch (IOException ex) {
            Logger.getLogger(MyProgram.class.getName()).log(Level.SEVERE, null, ex);
        }

    }

代码中缺少什么？

【问题讨论】：

标签： java jbutton jtextfield

【解决方案1】：

您首先要检查哪个TextField 拥有焦点，然后请求下一个字段的焦点。在这种方法中，您请求关注 lName，然后是 sNumber，然后您将最终获得拥有焦点的 lResult。

public void actionPerformed(ActionEvent e) {
    //creates a file for the next button output
    final File file = new File("NextOutput.txt");
    //creates a printwriter to output to file everytime next button is clicked (overwrite)
    boolean lNameFocus = lName.isFocusOwner();
    boolean sNumberFocus = sNumber.isFocusOwner();
    boolean fNameFocus = fName.isFocusOwner();
    boolean lResultsFocus = lResults.isFocusOwner();

    try (PrintWriter output = new PrintWriter(new FileWriter(file))) {
        //If none of the fields is owning the focus then lName requests the focus
        if (!(lNameFocus && sNumberFocus && fNameFocus && lResultsFocus)) {
            String s = fName.getText();
            output.print(s + " ");
            lName.requestFocus();
        //if lName is owning the focus then sNumber should be next to request
        } else if (lNameFocus) {
            String s1 = lName.getText();
            output.append(s1 + " ");
            sNumber.requestFocus();
        // and so on
        } else if (sNumberFocus) {
            String s2 = sNumber.getText();
            output.append(s2 + " ");
            lResults.requestFocus();
            String s3 = lResults.getText();
            output.append(s3 + " ");
        }

    } catch (IOException ex) {
        Logger.getLogger(MyProgram.class.getName()).log(Level.SEVERE, null, ex);
    }
}

【讨论】：