睡在java

Question

我试图让填充的圆圈缓慢地移动到更大圆圈的中心 使用Thread.sleep（mili seconds）但它似乎无法工作 - 它就像睡眠工作只有一次虽然它在一个循环中。

这是代码：

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseListener;
import org.eclipse.swt.events.MouseMoveListener;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class MouseListenerUsing {   
    static int i =0, R1=75,inCircleX=100,inCircleY=100,oldX,oldY, outCircleX=inCircleX , outCircleY=inCircleY, R2=200,dist=1;
  public static void main(String[] args) {
    final Display display = new Display();
    Shell shell = new Shell(display);
    shell.setSize(430, 460);
    final Canvas c=new Canvas(shell,SWT.BORDER);
    c.setSize(370,380);
    c.setLocation(21, 21);

    c.addPaintListener(new PaintListener(){
        public void paintControl(PaintEvent e) { 
            e.gc.setBackground(display.getSystemColor(SWT.COLOR_BLUE));
            e.gc.drawOval(outCircleX-((R2-R1)/2), outCircleY-((R2-R1)/2), R2, R2);
            e.gc.fillOval(inCircleX, inCircleY, R1, R1);    
        }       
    });    
    c.addMouseMoveListener(new MouseMoveListener(){
        @Override
        public void mouseMove(MouseEvent e){
            if (i==2)   
            {
                if (Math.sqrt(Math.pow((inCircleX+(R1/2))-((outCircleX-((R2-R1)/2)+(R2/2))),2)+Math.pow((inCircleY+(R1/2))-((outCircleY-((R2-R1)/2))+(R2/2)),2))<=R2/2)
                {   // distance between the two centers                                 
                    inCircleX = e.x+oldX;
                    inCircleY = e.y+oldY;
                    c.redraw();
                }
            }
        }       
    });
    c.addMouseListener(new MouseListener() {
        public void mouseDoubleClick(MouseEvent e) {System.exit(0);}
        public void mouseDown(MouseEvent e) 
        {        
            if (Math.sqrt(Math.pow(e.x-inCircleX-R1/2,2)+Math.pow(e.y-inCircleY-R1/2,2))<=R1/2)
            {
                oldX=inCircleX-e.x;
                oldY=inCircleY-e.y;
                i=2;
            }
        }
        public void mouseUp(MouseEvent e)
        {        
            i=1;
            int flagY=0,flagX=0;

            if ((inCircleX+(R1/2))>(outCircleX-((R2-R1)/2)+(R2/2))) flagX=1;
            else if ((inCircleX+(R1/2))<(outCircleX-((R2-R1)/2)+(R2/2))) flagX=0;
            if ((inCircleY+(R1/2))>(outCircleY-((R2-R1)/2)+(R2/2))) flagY=1;
            else if ((inCircleY+(R1/2))<(outCircleY-((R2-R1)/2)+(R2/2))) flagY=0;

            double it = (Math.sqrt(Math.pow((inCircleX+(R1/2))-((outCircleX-((R2-R1)/2)+(R2/2))),2)+Math.pow((inCircleY+(R1/2))-((outCircleY-((R2-R1)/2))+(R2/2)),2))); //distance between centers
            while (it>0)
            {
                    if (flagX==1) 
                    {   if ((inCircleX - dist+(R1/2))<(outCircleX-((R2-R1)/2)+(R2/2))) flagX=0;
                        if (flagX ==1) inCircleX = inCircleX - dist;
                    }
                    if ( flagX==0)  
                    {   
                        if ((inCircleX + dist+(R1/2))>(outCircleX-((R2-R1)/2)+(R2/2))) flagX=1;
                        if (flagX ==0) inCircleX = inCircleX + dist;
                    }
                    if ( flagY==1) 
                    {
                        if ((inCircleY - dist+(R1/2))<(outCircleY-((R2-R1)/2)+(R2/2))) flagY=0;
                        if (flagY ==1) inCircleY = inCircleY - dist;
                    }
                    if (flagY==0)   
                    {
                        if ((inCircleY + dist+(R1/2))>(outCircleY-((R2-R1)/2)+(R2/2))) flagY=1;
                        if (flagY ==0) inCircleY = inCircleY + dist;
                    }
                    try {
                        Thread.sleep(10);
                    } catch (InterruptedException e1) {
                        e1.printStackTrace();
                    }           
                    c.redraw(); 
                    it--;
            }               
            inCircleX = outCircleX;
            inCircleY = outCircleY;
            c.redraw();
        }
    });
    shell.open();
    while(!shell.isDisposed())
        if (!display.readAndDispatch())
            display.sleep();    
    display.dispose();
  }
 }

有人知道这个问题吗？

谢谢

Answer 1

首先，你不应该在UI线程（UI分派线程）中睡觉。如果你这样做，你就会暂停UI绘图和工作，这很糟糕。

Thread.sleep将毫秒作为参数，而不是秒。我非常怀疑你能否认识到是否发生了10毫秒的暂停。我想你想要10秒，10000毫秒。

此外，我认为没有理由在那里睡觉。