如何使用 GridBagLayout 在 JPanel 中對齊組件中心？

Question

當我嘗試對齊我的組件時，它會在左側或右側。

所以我只想要解決這個問題的解決方案，並告訴我如何將面板的大小設置為 400 x 350 像素。

這是我的代碼.... titleLabel和ResultLabel應該居中對齊

public TimeGui() {

    layout = new GridBagLayout();
    setSize(400, 350);  //**Its not working**
    setBackground(Color.LIGHT_GRAY);
    setBorder(BorderFactory.createLineBorder(Color.BLACK));
    setBorder(new TitledBorder(new EtchedBorder(), "Time Conversion") );

    setLayout(layout);
    layoutConstraints = new GridBagConstraints();       
    textField1 = new JTextField(10);
    textField2 = new JTextField(10);

    String[] names1 = {"Seconds", "Minutes", "Hours", "Days", "Weeks"};


    comboBox1 = new JComboBox<>(names1);
    comboBox2 = new JComboBox<>(names1);

    titleLabel = new JLabel("Time Conversion Unit", JLabel.CENTER);
    resultLabel = new JLabel("Result Label");
    equalLabel = new JLabel("=");

    convertButton = new JButton("Convert");


    layoutConstraints.fill = GridBagConstraints.HORIZONTAL;
    Insets inset = new Insets(10, 10, 10, 10);
    layoutConstraints.anchor = GridBagConstraints.CENTER;

    addComponent(titleLabel, 0, 0, 2, 2, inset ); // I tried (0,1,2,2) 



    addComponent(comboBox1, 3, 0, 2, 3, inset);

    addComponent(comboBox2, 3, 2, 2, 3, inset);

    addComponent(textField1, 6, 0, 1, 2, inset);

    addComponent(equalLabel, 6, 1, 1, 2, inset);

    addComponent(textField2, 6, 2, 1, 2, inset);

    addComponent(resultLabel, 8, 1, 2, 1, inset);

    addComponent(convertButton, 10, 0, 2, 2, inset);

}

private void addComponent(Component component, int row,
        int column, int width, int height, Insets inset1) {
    layoutConstraints.gridx = column;
    layoutConstraints.gridy = row;
    layoutConstraints.gridwidth = width;
    layoutConstraints.gridheight = height;
    layoutConstraints.insets = inset1;
    layout.setConstraints(component, layoutConstraints);
    add(component);
}
}

Answer 1

問題在於您的gridwidth和fill屬性...

基本上我改變的只是......

addComponent(titleLabel, 0, 0, GridBagConstraints.REMAINDER, 2, inset); // I tried (0,1,2,2) 
addComponent(comboBox1, 3, 0, 1, 3, inset);
addComponent(comboBox2, 3, 2, 1, 3, inset);
addComponent(textField1, 6, 0, 1, 2, inset);
addComponent(equalLabel, 6, 1, 1, 2, inset);
addComponent(textField2, 6, 2, 1, 2, inset);
layoutConstraints.fill = GridBagConstraints.NONE;
addComponent(resultLabel, 8, 0, GridBagConstraints.REMAINDER, 1, inset);
addComponent(convertButton, 10, 0, GridBagConstraints.REMAINDER, 2, inset);

你可以和其他幾個人一起玩。

至於定義面板的實際大小，你能做的最好的事情就是覆蓋TimeGui的getPreferredSize方法......

@Override
public Dimension getPreferredSize() {
    return new Dimension(400, 350);
}

這將向父容器“建議”您想要布置的大小。 請記住，這是一個可選值，布局管理器完全有權忽略它。