creatimg.java~47~

实例大全

package dyimg;

/**
 * Title:
 * Description:
 * Copyright:    Copyright (c) 2001
 * Company:
 * @author songxf
 * @version 1.0
 */
import java.awt.image.*;
import java.awt.*;
import java.io.*;

public class creatImg {

    private Frame m_frame;
    private Graphics m_g;
    private Image m_img;
    private int m_nWidth=400;
    private int m_nHeight=500;

    private int m_nX=100;
    private int m_nY=100;
    private double m_dTheta=Math.PI/4;
    private int m_nRadius=40;
    private int m_nStep=10;
    private Color m_bgColor=Color.white;
    private Color m_forColor=Color.black;

    public creatImg()
    {

    }

    /**生成一个offscreen的Image对象，并且获得它的Graphics对象**/
    public void init()
    {
        m_frame = new Frame();
        m_frame.addNotify();
        try
        {
            m_img = m_frame.createImage(m_nWidth,m_nHeight);
            m_g = m_img.getGraphics();
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }

    /**设置图片的宽度**/
    public void setWidth(int nWidth)
    {
        m_nWidth=nWidth;
    }

    /**设置图片的高度**/
    public void setHeight(int nHeight)
    {
        m_nHeight=nHeight;
    }


    /**设置小球每步走的步长**/
    public void setStep(int nStepDist)
    {
        m_nStep=nStepDist;
    }

    /**设置小球移动的方向**/
    public void setTheta(double dTheta)
    {
        m_dTheta=dTheta;
    }

    /**设置小球的初始坐标X**/
    public void setStartX(int nX)
    {
        m_nX=nX;
    }

    /**设置小球的初始坐标Y**/
    public void setStartY(int nY)
    {
        m_nY=nY;
    }

    /**画一个不断的移动的小球**/
    public void drawBall()
    {
        m_g.setColor(m_bgColor);
        m_g.fillRect(0,0,m_nWidth,m_nHeight);

        m_nX+=(int)(m_nStep*Math.cos(m_dTheta));
        m_nY+=(int)(m_nStep*Math.sin(m_dTheta));

        /**判断是否碰壁**/
        boolean bTouch=false;
        if(m_nX<m_nRadius ||(m_nWidth-m_nX)<m_nRadius)
        {
            m_dTheta=Math.PI-m_dTheta;
            bTouch=true;
        }

        if(m_nY<m_nRadius || (m_nHeight-m_nY)<m_nRadius)
        {
            m_dTheta=-m_dTheta;
            bTouch=true;
        }

        if(bTouch)
        {
            m_nX+=m_nStep*(int)Math.cos(m_dTheta);
            m_nY+=m_nStep*(int)Math.sin(m_dTheta);
        }

        m_g.setColor(m_forColor);
        m_g.fillOval(m_nX-m_nRadius,m_nY-m_nRadius,2*m_nRadius,2*m_nRadius);
    }

    /**Image对象生成PNG图片的byte数组**/
    public byte[] getImage()
    {
        drawBall();
        byte ab[] = null;
        try
        {
            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(100000);
            if (!encode(byteArrayOutputStream, 1))
                System.out.println("转换失败");
            ab = byteArrayOutputStream.toByteArray();
            byteArrayOutputStream.flush();
            byteArrayOutputStream.close();
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return ab;
    }

    /**转换，并将转换生成的PNG格式的文件输出到一个输出流里头，i为PNG格式的压缩率**/
    public boolean encode(OutputStream outputStream, int i)
    {
        try
        {
            boolean flag;
            PngEncoder pngEncoder = new PngEncoder(m_img);
            pngEncoder.setCompressionLevel(i);
            byte ab[] = pngEncoder.pngEncode();
            if (ab == null)
                System.out.println("图片是空的");
            else
                outputStream.write(ab);
            outputStream.flush();
            return true;
        }
        catch (Exception ex)
        {
            ex.printStackTrace();
        }
        return false;
    }
}