Question

请注意，我发现了一个类似的帖子here，但这个问题似乎是一直存在这个问题，并没有真正提供关于为什么会发生这种情况的探索，只是另一种方法。

我正在创建一个Stratego游戏，现在我正在创建一个游戏可以交换他们的棋子然后提交棋盘布局作为他们的军队起始位置的棋盘。

我在每个框架上都有一个JButton（每个玩家一个，第二个在第一个玩家提交并离开计算机后显示），第一个框架上的JButton只有在你将其悬停时才被隐藏，但只是在Eclipse打开后程序第一次运行。

有人可以探讨一下为什么会发生这种情况吗？

主要的跑步课程

LogicInterpreter logic = new LogicInterpreter();

    Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();

    InputFrame inputPlayer1 = new InputFrame(logic, 1, "red", 600, 600);
    inputPlayer1.setLocation(dim.width / 2 - inputPlayer1.getSize().width/2,
            dim.height / 2 - inputPlayer1.getSize().height / 2);

    while(!logic.isSetUp1()){
        //Just to make it work
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    //Now bring up board 2

    InputFrame inputPlayer2 = new InputFrame(logic, 2, "blue", 600, 600);
    inputPlayer2.setLocation(dim.width / 2 - inputPlayer2.getSize().width/2,
            dim.height / 2 - inputPlayer2.getSize().height / 2);

    while(!logic.isSetUp2()){
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    //Will eventually open the main board
    openBoards(logic);
}

这是输入帧的相关设置代码

public class InputFrame extends JFrame {

private static final long serialVersionUID = 1L;
private LogicInterpreter holder;
private Panel2 jp;
private int height, width;
private Map<Integer, ArrayList<Integer>> lakeCoords = new HashMap<>();
private List<Piece> pieces = new ArrayList<>();
private int playernumber;
private String playerColor;
Piece selectedPiece;
Piece secondSelectedPiece;
boolean hidePieces = false;

JButton submit = new JButton("SUBMIT");

public void addCoords() {
    lakeCoords.put(3, new ArrayList<Integer>(Arrays.asList(6, 5)));
    lakeCoords.put(4, new ArrayList<Integer>(Arrays.asList(6, 5)));
    lakeCoords.put(7, new ArrayList<Integer>(Arrays.asList(6, 5)));
    lakeCoords.put(8, new ArrayList<Integer>(Arrays.asList(6, 5)));
}

public void createPieces() {
    int y = 1;

    if (playernumber == 2) {
        y = 6;
    }

    List<Integer> openValues = new ArrayList<>();

    openValues.add(1);
    openValues.add(2);
    openValues.add(11);
    openValues.add(12);
    for (int x = 0; x < 2; x++) {
        openValues.add(3);
    }
    for (int x = 0; x < 3; x++) {
        openValues.add(4);
    }
    for (int x = 0; x < 4; x++) {
        openValues.add(5);
        openValues.add(6);
        openValues.add(7);
    }
    for (int x = 0; x < 5; x++) {
        openValues.add(8);
    }
    for (int x = 0; x < 8; x++) {
        openValues.add(9);
    }
    for (int x = 0; x < 6; x++) {
        openValues.add(10);
    }

    Collections.sort(openValues);
    for (int x = 1; x <= 10; x++) {
        for (int z = y; z <= 4; z++) {

            // 1x1 Marshal
            // 2x1 General
            // 3x2 Colonel
            // 4x3 Major
            // 5x4 Captain
            // 6x4 Lieutenant
            // 7x4 Sergeant
            // 8x5 Miner
            // 9x8 Scout
            // 10x6 Bomb
            // 11x1 Flag
            // 12x1 Spy

            Piece piece = new Piece(new Coords(x, z), openValues.get(0), playerColor);

            openValues.remove(0);
            pieces.add(piece);
        }
    }
}

public InputFrame(LogicInterpreter holder, int playerNumber, String playerColor, int height, int width) {
    this.height = height;
    this.width = width;
    playernumber = playerNumber;
    this.playerColor = playerColor;
    setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    addCoords();
    this.holder = holder;
    createPieces();
    jp = new Panel2(height, width);
    setResizable(false);
    jp.setBackground(new Color(235, 202, 158));
    setTitle("Player " + playerNumber + " Arrangement GUI     ||     Click Submit When Ready");
    jp.setPreferredSize(new Dimension(600, 600));
    jp.setLayout(null);
    jp.addMouseListener(new HandleMouse());
    getContentPane().add(jp);
    pack();
    setVisible(true);

    if(playernumber == 1)
        submit.setBounds(width / 10 * 4, height / 10 * 7, width / 10 * 2, height / 10 * 2);
    else
        submit.setBounds(width / 10 * 4, height / 10, width / 10 * 2, height / 10 * 2);
    submit.setFont(new Font("Arial", Font.BOLD, width * 20 / 600));
    submit.setBackground(Color.LIGHT_GRAY);
    submit.addActionListener(new CloseListener(this));
    jp.add(submit);
}

//More stuff down here about logic and stuff

public class Panel2 extends JPanel {

    private static final long serialVersionUID = 1L;
    int height = 0;
    int width = 0;

    public Panel2(int height, int width) {
        this.height = height;
        this.width = width;
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        for (int x = 0; x < width; x += width / 10) {
            for (int y = 0; y < height; y += height / 10) {
                boolean fill = false;
                for (Entry<Integer, ArrayList<Integer>> coords : lakeCoords.entrySet()) {
                    if ((coords.getKey() - 1 == x / 60 && coords.getValue().get(0) - 1 == y / 60)
                            || (coords.getKey() - 1 == x / 60 && coords.getValue().get(1) - 1 == y / 60)) {
                        fill = true;
                        break;
                    }
                }
                if (fill) {
                    g.setColor(Color.BLUE);
                    g.fillRect(x, y, width / 10, height / 10);
                    g.setColor(Color.BLACK);
                    g.drawRect(x, y, width / 10, height / 10);
                } else {
                    g.setColor(Color.BLACK);
                    g.drawRect(x, y, width / 10, height / 10);
                }
            }
        }

        if(hidePieces){
            for (Piece piece : pieces) {
                try {
                    g.drawImage(ImageIO.read(new File(playerColor + "_pieces/" + (playerColor.equals("blue") ? "Blue" : "Red") + "_Strat_Piece"
                            + ".png")), piece.getX() * width / 10 - width / 10,
                            piece.getY() * height / 10 - height / 10, width / 10, height / 10, null);
                } catch(Exception e){}
            }
        } else {
            for (Piece piece : pieces) {
                g.drawImage(piece.getImage(), piece.getX() * width / 10 - width / 10,
                        piece.getY() * height / 10 - height / 10, width / 10, height / 10, null);
            }

            if (selectedPiece != null) {
                g.setColor(Color.BLUE);
                g.drawImage(selectedPiece.getImage(), selectedPiece.getX() * width / 10 - width / 10,
                        selectedPiece.getY() * height / 10 - height / 10, width / 10, height / 10, null);
                g.drawRect(selectedPiece.getX() * width / 10 - width / 10,
                        selectedPiece.getY() * height / 10 - height / 10, width / 10, height / 10);
            }
        }
    }
}

Answer 1

 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    databaseHelper = new MyDatabaseHelper(this);
    // Adding categories to DB.
    databaseHelper.addCategory("Example1");
    databaseHelper.addCategory("John");
    databaseHelper.addCategory("Michael");

}

并且第一帧上的JButton只有在你悬停它之前才会被隐藏，但只是在Eclipse打开后第一次运行该程序。

这意味着在将所有组件添加到框架之前，您可以使框架可见。

所以基本逻辑的顺序是：

setVisible(true);

....

jp.add(submit); // Note the add() is after the setVisible()

Answer 2

必须在EDT中创建Swing组件。调用sleep（）是EDT将阻止UI并且永远不是一个好主意。有关EDT的详细信息，请参阅此处：https://docs.oracle.com/javase/tutorial/uiswing/concurrency/dispatch.html

JButton隐藏直到首次启动

2 个答案: