GUI FlowLayout，锁定所有组件位置

Question

以下是我所尝试的：

public class CopyFile extends JFrame{

private JFileChooser fc;
private JButton copyButton;
private JButton chooseFileButton;
private JButton destinationButton;
private File workingDirectory;
private JLabel sourceLabel;
private JTextArea displayCopyText;
private JLabel destinationLabel;
private JTextField sourceText;
private JLabel copyText;
private JTextField destinationText;

public static void main(String [] args) {
    CopyFile go = new CopyFile();
    go.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    go.setSize(500, 150);
    go.setVisible(true);
}

public CopyFile() {
    super("Copy a text file");
    setLayout(new FlowLayout());
    fc = new JFileChooser();

    //Open dialog box inside project folder to make easier to find files
    workingDirectory = new File(System.getProperty("user.dir"));
    fc.setCurrentDirectory(workingDirectory);
    //create labels and buttons for window
    chooseFileButton = new JButton("CHOOSE SOURCE FILE");
    destinationButton = new JButton("DESTINATION FOLDER");
    copyButton = new JButton("COPY FILE");      
    sourceLabel = new JLabel("SOURCE FILE: ", JLabel.CENTER);
    sourceText = new JTextField(15);
    sourceText.setEditable(false);
    destinationText = new JTextField(15);
    destinationText.setEditable(false); 
    destinationLabel = new JLabel("DESTINATION:", JLabel.CENTER);
    //JScrollPane SP = new JScrollPane();       
    displayCopyText = new JTextArea();
    displayCopyText.setPreferredSize(new Dimension(300, 50));
    displayCopyText.setRows(2);
    displayCopyText.setLineWrap(true);
    displayCopyText.setWrapStyleWord(true);
    displayCopyText.setEditable(false);     



    //add everything to JFrame  
    add(sourceLabel);
    add(sourceText);
    add(chooseFileButton);  
    add(destinationLabel);
    add(destinationText);
    add(destinationButton);
    //add(copyText);
    add(displayCopyText);
    add(copyButton);

    //Create TheHandler object to add action listeners for the buttons.
    TheHandler handler = new TheHandler();
    chooseFileButton.addActionListener(handler);
    destinationButton.addActionListener(handler);
    copyButton.addActionListener(handler);
}

//Inner class to create action listeners    
private class TheHandler implements ActionListener {
    private File selectedDestinationFile;
    private File selectedSourceFile;
    private int returnVal;
    public void actionPerformed(ActionEvent event) {



        //Selecting a source file and displaying what the user is doing.
        if(event.getSource() == chooseFileButton) {     
            returnVal = fc.showOpenDialog(null);
            //Set the path for the source file. 
            if(returnVal == JFileChooser.APPROVE_OPTION) {  
                selectedSourceFile = fc.getSelectedFile();
                sourceText.setText(selectedSourceFile.getName());   
            }       
        }//end if

        //Handle destination button.
        if(event.getSource() == destinationButton) {
            returnVal = fc.showSaveDialog(null);
            if(returnVal == JFileChooser.APPROVE_OPTION) {
                selectedDestinationFile = fc.getSelectedFile();
                destinationText.setText(fc.getSelectedFile().getAbsolutePath());    
            }               
        }//end if

        //Handle copy button
        if(event.getSource() == copyButton) {
            Path sourcePath = selectedSourceFile.toPath();
            Path destinationPath = selectedDestinationFile.toPath();        
            try {
                Files.copy(sourcePath,  destinationPath);
            } catch (IOException e) {
                e.printStackTrace();
            }   

            if(returnVal == JFileChooser.APPROVE_OPTION) {      
                displayCopyText.append("SUCCESSFULLY COPIED:\n" 
                                + selectedDestinationFile.getName());   
            }
            else {
                displayCopyText.append("COPY WAS CANCELED BY USER.\n");
            }   
        }//end if

    }//end actionPerformed      
}//end TheHandler class
}//end class

Answer 1

您可以使用JFrame::SetResizable(false)锁定可调整大小的窗口。

所以您的代码可能像

public static void main(String[] args) {
        CopyFile go = new CopyFile();
        go.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        go.setResizable(false);   //No resize is possible

       go.setSize(500, 150);
       go.setVisible(true);
}

这样可以解决你的这个问题