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所以我在这里找到了这段代码,它可以工作,它只是在拖动时在图像中引起相当多的抖动 - (拖动的速度越快,图像抖动越多)。OP说它没有优化,因为它是一个死帖,我想我会看看这里是否有人可以提供帮助!我也尝试过stack中的代码,但我无法让它做任何事情。如果有人对此代码有任何建议,或者更好的解决方案,我很想听听!

注意,我需要拖动的 Jpanel(paintComponent 绘制对象)位于滚动窗格内!

   //initial reference point  
   private Point mouseLocation;  
   public void mousePressed(MouseEvent evt){  
      mouseLocation = evt.getPoint();  
   }  
   public void mouseDragged(MouseEvent evt){  
      //current mouse location  
      Point newLoc = evt.getPoint();  
      //deltas  
      int deltaX = newLoc.x-mouseLocation.x;  
      int deltaY = newLoc.y-mouseLocation.y;  
      p.setLocation(p.getX()+deltaX,p.getY()+deltaY);  
      //move the reference point to the current location  
      this.mouseLocation = newLoc;  
   }  

是一个显示抖动的示例程序!

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1 回答 1

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所以我在这里找到了这段代码,它有效,只是引起了很多颤抖

然后我会说它不起作用。而且,如果您仔细阅读该帖子,则 OP 还声明它不起作用。

此外,按钮并没有严格跟随鼠标,所以在我看来这很可怕。

现在,需要考虑两件事:

  1. 您正在使用evt.getPoint():该方法的值是相对于JButton. 当您四处移动JButton时,您无法将该方法的值与前一个方法的值进行比较(因为您的按钮正在移动)。一种简单的解决方案是将这些点相对于固定面板转换为固定面板,例如不移动的父面板。Tadaam:它现在运行流畅,按钮完美地跟随你的鼠标。
  2. 当您使用 LayoutManager 时,您不能调用setLocation(也不能调用 setBounds 或 setSize()),因为这是 LayoutManager 的工作,一旦他们重新布局您的容器,按钮就会被设置回其原始位置(即我猜你不想要)。有几种方法可以解决这个问题,但通常最简单的一种是使用绝对定位(即,将布局设置为null)。最后,这意味着您必须执行 LayoutManager 之前所做的任何事情。

这是一个小演示(有缺陷,但演示了基本原理):

import java.awt.Component;
import java.awt.Point;

import javax.swing.SwingUtilities;

/**
 * 
 * @author Stuart.Bradley
 */
public class NewJFrame extends javax.swing.JFrame {
    private Point mouseLocation;

    /**
     * Creates new form NewJFrame
     */
    public NewJFrame() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form. WARNING: Do NOT modify this code. The content of this
     * method is always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {
        jButton1 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jButton1.setText("jButton1");
        jButton1.addMouseListener(new java.awt.event.MouseAdapter() {
            @Override
            public void mousePressed(java.awt.event.MouseEvent evt) {
                jButton1MousePressed(evt);
            }
        });
        jButton1.addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
            @Override
            public void mouseDragged(java.awt.event.MouseEvent evt) {
                jButton1MouseDragged(evt);
            }
        });
        setLayout(null);
        jButton1.setSize(jButton1.getPreferredSize());
        add(jButton1);
        setSize(300, 300);
    }// </editor-fold>

    private void jButton1MouseDragged(java.awt.event.MouseEvent evt) {
        // current mouse location
        Point newLoc = SwingUtilities.convertPoint(evt.getComponent(), evt.getPoint(), jButton1.getParent());
        // deltas
        int deltaX = newLoc.x - mouseLocation.x;
        int deltaY = newLoc.y - mouseLocation.y;
        jButton1.setLocation(jButton1.getX() + deltaX, jButton1.getY() + deltaY);
        // move the reference point to the current location
        this.mouseLocation = newLoc; // TODO add your handling code here:
    }

    private void jButton1MousePressed(java.awt.event.MouseEvent evt) {
        mouseLocation = SwingUtilities.convertPoint(evt.getComponent(), evt.getPoint(), jButton1.getParent()); // TODO add your
    }

    /**
     * @param args
     *            the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        // <editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /*
         * If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel. For details see
         * http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        // </editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify
    private javax.swing.JButton jButton1;
    // End of variables declaration
}
于 2013-01-30T23:42:13.803 回答