Swing - 使用getComponent（）更新所有JButton [英] Swing - using getComponent() to update all JButtons

问题描述

我正在制作一个tictactoe游戏，其中每个棋盘片由JButton代表。当有人单击该按钮时，文本将更改为X或O。我正在写一个重置功能，它将所有按钮中的文本重置为。我正在使用getComponents（）方法从数组中访问所有按钮。

I am making a tictactoe game where each board piece is represented by a JButton. When someone clicks the button the text is changed to "X" or "O". I am writing a reset function which resets the text in all the buttons to "". I am accessing all the buttons from an array using getComponents() method.

我只是想知道我做错了什么因为这个位编译正确

I just wondered what I am doing wrong because this bit compiles correctly

component[i].setEnabled(true);

但这一位不是

component[i].setText("");

我收到无法找到符号错误。请看下面的代码。我只包含了我认为必要的代码。

I get a "cannot find symbol" error. Please have a look at the code below. I only included the code I thought was necessary.

    JPanel board = new JPanel(new GridLayout(3, 3));

    JButton button1 = new JButton("");
    JButton button2 = new JButton("");
    JButton button3 = new JButton("");
    JButton button4 = new JButton("");
    JButton button5 = new JButton("");
    JButton button6 = new JButton("");
    JButton button7 = new JButton("");
    JButton button8 = new JButton("");
    JButton button9 = new JButton("");

    board.add(button1);
    board.add(button2);
    board.add(button3);
    board.add(button4);
    board.add(button5);
    board.add(button6);
    board.add(button7);
    board.add(button8);
    board.add(button9);

public void reset()
{
    Component[] component = board.getComponents();

    // Reset user interface
    for(int i=0; i<component.length; i++)
    {
        component[i].setEnabled(true);
        component[i].setText("");
    }

        // Create new board logic
        tictactoe = new Board();
        // Update status of game
        this.updateGame();
}

推荐答案

getComponents（）返回一个 Component 的数组，它没有 setText（String）方法。您应该将 JButton 实例保留为类成员（这是我强烈建议的方式），并直接使用它们，或循环遍历所有组件对象，检查它是否是 JButton 实例。如果是，则显式地将其转换为 JButton ，然后在其上调用 setText（String）。例如，

getComponents () returns an array of Components, which does not have a setText(String) method. You should either keep your JButton instances as class members (this is the way I strongly suggest), and use them directly, or loop through all the Component objects, check if it is a JButton instance. If it is, explicitly cast it as a JButton, then call setText(String) on it. E.g.

public void reset()
{
    Component[] component = board.getComponents();

    // Reset user interface
    for(int i=0; i<component.length; i++)
    {
        if (component[i] instanceof JButton)
        {
            JButton button = (JButton)component[i];
            button.setEnabled(true);
            button.setText("");
        }

    }
}

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