java - 事件监听器卡住 (Java)

Question

好吧，我的问题是当您拖动鼠标时，mouseMoved 被卡住，这是 MouseMotionListener 中的方法之一( mouseMoved 和 mouseDragged )。我想也许 mouseDragged 正在卡住 mouseMoved，如果有人可以帮助我，让它不这样做，那就太好了。

import javax.swing.JFrame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseEvent;
import java.awt.Rectangle;
import java.lang.Runnable;
import java.awt.RenderingHints;
import java.awt.Graphics2D;
import java.awt.Color;

public class Window extends JFrame implements MouseMotionListener, Runnable {
    protected static int xWindow = 640;
    protected static int yWindow = 480;
    private Image dbi;
    private Graphics dbg;
    private int xMouse;
    private int yMouse;

    public void paint( Graphics g ) {
        dbi = createImage( getWidth(), getHeight() );
        dbg = dbi.getGraphics();
        paintComponent( dbg );
        g.drawImage( dbi, 0, 0, this );
    }

    public void paintComponent( Graphics g ) {
        Graphics2D g2d = ( Graphics2D ) g;
        g2d.setRenderingHint( RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON );
        g2d.setColor( Color.RED );
        g2d.drawString( "Mouse X: " + xMouse + " | Y: " + yMouse, 15, 40 );

        repaint();
    }

    public void mouseDragged( MouseEvent e ) {
        e.consume();
    }

    public void mouseMoved( MouseEvent e ) {
        xMouse = e.getX();
        yMouse = e.getY();
        e.consume();
    }

    public void run() {
        while ( true ) {
            try {
                Thread.sleep( 1 );
            } catch( Exception e ) {
                e.printStackTrace();
            }
        }
    }

}

Answer 1

您正在从 paintComponent 调用 repaint，这会导致以下方法调用链无限重复:

paint -> (manual call to) paintComponent 

要利用 Swing 的优化绘制模型，最好不要在 JFrame 等顶级容器中进行自定义绘制。将所有绘制功能提取到新的基于 JComponent 或 JPanel 的类并覆盖 paintComponent。 Swing 将在 repaint 上调用 paintComponent，因此无需直接调用。不要忘记调用 super.paintComponent(g)。

从 mouseMoved 中调用 repaint。

也不要调用 Thread.sleep，这会阻塞 EDT 并导致 UI 卡住。 Swing提供了自己的concurrency objects如Swing Timers .