如何用java画一个圆，并且让它运动？

静态圆：

import java.awt.Color

import java.awt.Graphics

import javax.swing.JFrame

public class OneAnt extends JFrame {

public void paint(Graphics g) {

int x = 100

int y = 80

int r = 50

g.setColor(Color.blue)

// 从x,y位置处画一个实心的圆

g.fillOval(x, y, 2 * r, 2 * r)

}

public static void main(String[] args)

{

OneAnt oa=new OneAnt()

oa.setSize(500, 300)

oa.setVisible(true)

}

}

动态圆可以用线程来实现

看看符合要求不？

Option Explicit

Dim x, y As Integer '匀速旋转小球的位置

Dim A As Integer '角度

Private Sub Form_Load()

Show

Me.Picture1.Width = 2000

Me.Picture1.Height = 2000

Me.Picture1.Scale (-1000, -1000)-(1000, 1000)

A = 0

Me.Timer1.Interval = 100

End Sub

Private Sub Timer1_Timer()

Me.Picture1.Cls

Me.Picture1.Circle (0, 0), 500

Me.Picture1.PSet (0, 0)

A = A + 1

If A = 360 Then A = 0

x = 500 * Sin(A)

y = 500 * Cos(A)

Me.Picture1.Circle (x, y), 20, vbRed

End Sub

在WM_TIMER消息里

{

圆周运动直接算坐标吧:用cos(x) sin(x)函数,x是弧度,不是角度.所以你得

2PI * iAngle /360把角度转成弧度

公式为:

x = y * sin( 2 * PI * iAngle / 360 )

y = y * cos( 2 * PI * iAngle /360 )

//比如iAngle==30度,那么Point(x,y)就在钟面时钟1点的位置

颜色改变的话,你直接hBrush = createSolidBrush(RGB(x,y,x) )这些数字你随便递增好了.然后就用Rectangle(rect.left, top, right ,bottom )画圆

}

注意的地方就是你的设置下SetROP2( hdc,R2_XNOR),把前一个小球重画一遍,这样它就消失了,不然你会看到无数个小球沿着圆周画下来.

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