GridBagConstraints，一个按钮的两倍高

Question

我正在尝试使用GridBagConstraints构建计算器。我希望等号按钮的高度是其他按钮的两倍，但它不起作用。

我的代码出了什么问题？

public class Main extends JFrame{

    JButton b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,bpoint,badd,bsub,bmul,bdiv,bx2,bsqrt,be,bpi,clear,bdel,plusminus,equal;
    JTextField result;

    public static void main(String[] args) {
        new Main();

    }   
    public Main(){
        this.setSize(500, 350);
        this.setLocationRelativeTo(null);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setTitle("Calculator");
        JPanel thePanel = new JPanel();
        thePanel.setLayout(new GridBagLayout());
        GridBagConstraints theGrid = new GridBagConstraints();

        theGrid.gridx = 1;
        theGrid.gridy = 1;
        theGrid.gridwidth = 1;
        theGrid.gridheight = 1;
        theGrid.weightx = 1;
        theGrid.weighty = 1;
        theGrid.insets = new Insets(2,2,2,2);
        theGrid.anchor = GridBagConstraints.CENTER;
        theGrid.fill = GridBagConstraints.BOTH;

        result = new JTextField();
        Font font = new Font("Tahoma", Font.PLAIN, 18);
        result.setFont(font);

        b1 = new JButton("1");
        b2 = new JButton("2");
        b3 = new JButton("3");
        b4 = new JButton("4");
        b5 = new JButton("5");
        b6 = new JButton("6");
        b7 = new JButton("7");
        b8 = new JButton("8");
        b9 = new JButton("9");
        b0 = new JButton("0");
        bpoint = new JButton(".");
        badd = new JButton("+");
        bsub = new JButton("-");
        bmul = new JButton("*");
        bdiv = new JButton("/");

        plusminus = new JButton("±");
        equal = new JButton("=");
        bx2 = new JButton("x²");
        bsqrt = new JButton("√");
        bdel = new JButton("←");

        be = new JButton("℮");
        bpi = new JButton("Π");
        clear = new JButton("AC");


        theGrid.gridwidth = 2;
        thePanel.add(clear, theGrid);
        theGrid.gridwidth = 4;
        theGrid.gridx = 3;
        thePanel.add(result, theGrid);

        theGrid.gridwidth = 1;
        theGrid.gridx = 1;
        theGrid.gridy = 2;
        thePanel.add(b7, theGrid);
        theGrid.gridx = 2;
        thePanel.add(b8, theGrid);
        theGrid.gridx = 3;
        thePanel.add(b9, theGrid);
        theGrid.gridx = 4;
        thePanel.add(badd, theGrid);
        theGrid.gridx = 5;
        thePanel.add(bx2, theGrid);
        theGrid.gridx = 6;
        thePanel.add(bdel, theGrid);

        theGrid.gridy = 3;
        theGrid.gridx = 1;
        thePanel.add(b4, theGrid);
        theGrid.gridx = 2;
        thePanel.add(b5, theGrid);
        theGrid.gridx = 3;
        thePanel.add(b6, theGrid);
        theGrid.gridx = 4;
        thePanel.add(bsub, theGrid);
        theGrid.gridx = 5;
        thePanel.add(bsqrt, theGrid);
        theGrid.gridx = 6;
        thePanel.add(plusminus, theGrid);

        theGrid.gridy = 4;
        theGrid.gridx = 1;
        thePanel.add(b1, theGrid);
        theGrid.gridx = 2;
        thePanel.add(b2, theGrid);
        theGrid.gridx = 3;
        thePanel.add(b3, theGrid);
        theGrid.gridx = 4;
        thePanel.add(bmul, theGrid);
        theGrid.gridx = 5;
        thePanel.add(be, theGrid);

        theGrid.gridx = 6;
        theGrid.gridheight = 2;
        thePanel.add(equal, theGrid);

        theGrid.gridy = 5;
        theGrid.gridwidth = 2;
        theGrid.gridx = 1;
        thePanel.add(b0, theGrid);
        theGrid.gridwidth = 1;
        theGrid.gridx = 3;
        thePanel.add(bpoint, theGrid);
        theGrid.gridx = 4;
        thePanel.add(bdiv, theGrid);
        theGrid.gridx = 5;
        thePanel.add(bpi, theGrid);

        this.add(thePanel);
        this.setResizable(false);
        this.setVisible(true);
    }


}

Answer 1

您需要在使用后重置gridHeight约束，以便其余按钮的高度仅为1：

    theGrid.gridheight = 2;
    thePanel.add(equal, theGrid);
    theGrid.gridheight = 1; // added