Java Swing - 使用 getComponent() 更新所有 JButton
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Swing - using getComponent() to update all JButtons
提问by jimbo123
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.
我正在制作一个 tictactoe 游戏，其中每个棋盘都由一个 JButton 表示。当有人单击按钮时，文本会更改为“X”或“O”。我正在编写一个重置函数，它将所有按钮中的文本重置为“”。我正在使用 getComponents() 方法访问数组中的所有按钮。
I just wondered what I am doing wrong because this bit compiles correctly
我只是想知道我做错了什么，因为这部分编译正确
component[i].setEnabled(true);
but this bit does not
但这一点没有
component[i].setText("");
I get a "cannot find symbol" error. Please have a look at the code below. I only included the code I thought was necessary.
我收到“找不到符号”错误。请看下面的代码。我只包含了我认为必要的代码。
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();
}
采纳答案by Laf
getComponents ()returns an array of Components, which does not have a setText(String)method. You should either keep your JButtoninstances as class members (this is the way I strongly suggest), and use them directly, or loop through all the Componentobjects, check if it is a JButtoninstance. If it is, explicitly cast it as a JButton, then call setText(String)on it. E.g.
getComponents ()返回一个Component没有setText(String)方法的s数组。您应该将您的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，或者循环遍历所有Component对象，检查它是否是一个JButton实例。如果是，则将其显式转换为 a JButton，然后调用setText(String)它。例如
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("");
}
}
}
