Java实现的简单画图板示例

本文实例讲述了java实现的简单画图板。分享给大家供大家参考，具体如下：

这个画图板是我好久之前做的，之后浙大的同学需要做课设然后就花了一点时间将它改了一下，变得简单些能够方便扩充功能，同时学习java基础

先截图一下吧，就可以知道有哪些功能了~

三个分区，上面选择图形，下面选择颜色，立体圆就是一个分形，也先放着不需要的同学可以注释了它

代码很简单，就是jpanel进行分区，得到画笔，同时使用画图的函数就可以做到了

贴代码应该很快就会了~

主类

package awtdemo;
import java.awt.borderlayout;
import java.awt.color;
import java.awt.dimension;
import java.awt.flowlayout;
import javax.swing.jbutton;
import javax.swing.jframe;
import javax.swing.jpanel;
@suppresswarnings("serial")
public class drawmain extends jpanel {
    public static void main(string[] args) {
        // todo auto-generated method stub
        drawmain draw = new drawmain();
        draw.initui();
    }
    public void initui() {
        jframe jf = new jframe();
        jf.setsize(1000, 780);
        jf.settitle("简单画板");
        jf.setdefaultcloseoperation(3);
        jf.setlocationrelativeto(null);
        jf.setlayout(new borderlayout());
        // 实例化事件监听类
        drawlistener dl = new drawlistener(this);
        // 实现中间面板
        this.setbackground(color.white);
        jf.add(this, borderlayout.center);
        // 实现性状面板
        jpanel shapepanel = new jpanel();
        shapepanel.setbackground(color.black);
        shapepanel.setlayout(new flowlayout(flowlayout.center));
        shapepanel.setbackground(color.gray);
        ;
        string[] shape = { "直线", "曲线", "圆", "喷枪", "橡皮擦", "矩形", "椭圆", "圆角矩形",
                "弧线", "多边形", "图形", "三角形", "立体圆", };
        for (int i = 0; i < shape.length; i++) {
            jbutton button = new jbutton(shape[i]);
            button.setbackground(color.white);
            button.addactionlistener(dl); // 添加事件监听机制
            shapepanel.add(button);
        }
        jf.add(shapepanel, borderlayout.north);
        // 实现颜色面板
        jpanel colorpanel = new jpanel();
        colorpanel.setbackground(color.black);
        colorpanel.setlayout(new flowlayout(flowlayout.center));
        colorpanel.setbackground(color.gray);
        ;
        color[] color = { color.black, color.blue, color.white, color.gray,
                color.red, color.cyan, color.green, color.darkgray, color.pink };
        for (int i = 0; i < color.length; i++) {
            jbutton button = new jbutton();
            button.addactionlistener(dl); // 添加事件监听机制
            button.setpreferredsize(new dimension(30, 30));
            button.setbackground(color[i]);
            colorpanel.add(button);
        }
        jf.add(colorpanel, borderlayout.south);
        jf.setvisible(true);
        this.addmouselistener(dl);
        this.addmousemotionlistener(dl);
    }
}

监听辅助类

package awtdemo;
import java.awt.basicstroke;
import java.awt.color;
import java.awt.graphics2d;
import java.awt.renderinghints;
import java.awt.event.actionevent;
import java.awt.event.actionlistener;
import java.awt.event.mouseadapter;
import java.awt.event.mouseevent;
import java.util.random;
import javax.swing.jbutton;
public class drawlistener extends mouseadapter implements actionlistener {
    private int x1, y1, x2, y2;
    private int newx1, newy1, newx2, newy2;
    private graphics2d g;
    private drawmain df;
    private boolean flag = false;
    string shape = "直线";
    color color;
    private int[] arrx = new int[4];
    private int[] arry = new int[4];
    private int temp = 0;
    drawlistener(drawmain d) {
        df = d;
    }
    // 获取形状和颜色
    public void actionperformed(actionevent e) {
        if (e.getactioncommand().equals("")) {
            jbutton button = (jbutton) e.getsource();
            color = button.getbackground();
            system.out.println("color = " + color);
        } else {
            jbutton button = (jbutton) e.getsource();
            shape = button.getactioncommand();
            system.out.println("string = " + shape);
        }
    }
    // 实现画笔
    public void mousepressed(mouseevent e) {
        g = (graphics2d) df.getgraphics();
        g.setcolor(color);
        x1 = e.getx();
        y1 = e.gety();
    }
    public void mousereleased(mouseevent e) {
        x2 = e.getx();
        y2 = e.gety();
        if (shape.equals("直线")) {
            g.drawline(x1, y1, x2, y2);
        } else if (shape.equals("弧线")) {
            g.drawarc(x1, y1, math.abs(x2 - x1), math.abs(y2 - y1), 0, 180);
        } else if (shape.equals("多边形") && !flag) {
            g.drawline(x1, y1, x2, y2);
            newx1 = x1;
            newy1 = y1;
            newx2 = x2;
            newy2 = y2;
            flag = true;
        } else if (shape.equals("圆")) {
            g.drawoval(x1, y1, math.abs(x2 - x1), math.abs(y2 - y1));
        } else if (shape.equals("矩形")) {
            g.drawrect(x1, y1, math.abs(x2 - x1), math.abs(y2 - y1));
        } else if (shape.equals("圆角矩形")) {
            g.drawroundrect(x1, y1, math.abs(x2 - x1), math.abs(y2 - y1), 2, 10);
        } else if (shape.equals("椭圆")) {
            g.drawoval(x1, y1, math.abs(x2 - x1), math.abs(y2 - y1));
        }
    }
    public void mouseclicked(mouseevent e) {
        if (shape.equals("多边形") && flag) {
            x2 = e.getx();
            y2 = e.gety();
            if (e.getclickcount() == 2) {
                g.drawline(newx1, newy1, newx2, newy2);
                flag = false;
            }
            g.drawline(newx2, newy2, x2, y2);
            newx2 = x2;
            newy2 = y2;
        } else if (shape.equals("图形")) {
            arrx[temp] = e.getx();
            arry[temp] = e.gety();
            temp++;
            if (temp == 4) {
                int x = arrx[3];
                int y = arry[3];
                for (int i = 0; i <= 10000; i++) {
                    random ran = new random();
                    int k = ran.nextint(3);
                    x = (x + arrx[k]) / 2;
                    y = (y + arry[k]) / 2;
                    g.drawline(x, y, x, y);
                }
                temp = 0;
            }
        } else if (shape.equals("立体圆")) {
            // double a=-2,b=-2,c=-1.2,d=2;
            double a = 1.40, b = 1.56, c = 1.40, d = -6.56;
            double x = 0, xo = 0;
            double y = 0, yo = 0;
            color[] col = { color.blue, color.cyan, color.green, color.magenta,
                    color.red, color.yellow };
            for (int i = 0; i <= 90000; i++) {
                random r = new random(); // 增加颜色
                int r = r.nextint(col.length);
                g.setcolor(col[r]);
                // x=math.sin(a*yo)-math.cos(b*xo);
                // y=math.sin(c*xo)-math.cos(d*yo);
                x = d * math.sin(a * xo) - math.sin(b * yo);
                y = c * math.cos(a * xo) + math.cos(b * yo);
                int temp_x = (int) (x * 50);
                int temp_y = (int) (y * 50);
                g.drawline(temp_x + 500, temp_y + 300, temp_x + 500,
                        temp_y + 300);
                xo = x;
                yo = y;
            }
        } else if (shape.equals("三角形")) {
            double a = -2, b = -2, c = -1.2, d = 2;
            double x = 0, xo = 0;
            double y = 0, yo = 0;
            color[] col = { color.blue, color.cyan, color.green, color.magenta,
                    color.red, color.yellow };
            for (int i = 0; i <= 90000; i++) {
                random r = new random(); // 增加颜色
                int r = r.nextint(col.length);
                g.setcolor(col[r]);
                x = math.sin(a * yo) - math.cos(b * xo);
                y = math.sin(c * xo) - math.cos(d * yo);
                int temp_x = (int) (x * 50);
                int temp_y = (int) (y * 50);
                g.drawline(temp_x + 500, temp_y + 300, temp_x + 500,
                        temp_y + 300);
                xo = x;
                yo = y;
            }
        }
    }
    public void mousedragged(mouseevent e) {
        x2 = e.getx();
        y2 = e.gety();
        if (shape.equals("曲线")) {
            // g.setstroke(new basicstroke(10));
            // g.setrenderinghint(renderinghints.key_antialiasing,
            // renderinghints.value_antialias_on);
            g.drawline(x1, y1, x2, y2);
            x1 = x2;
            y1 = y2;
        } else if (shape.equals("橡皮擦")) {
            g.setstroke(new basicstroke(80));
            g.setrenderinghint(renderinghints.key_antialiasing,
                    renderinghints.value_antialias_on);
            g.setcolor(color.white);
            g.drawline(x1, y1, x2, y2);
            x1 = x2;
            y1 = y2;
        } else if (shape.equals("喷枪")) {
            // g.setstroke(new basicstroke(2)); //不用加粗
            // g.setrenderinghint(renderinghints.key_antialiasing,
            // renderinghints.value_antialias_on);
            for (int k = 0; k < 20; k++) {
                random i = new random();
                int a = i.nextint(8);
                int b = i.nextint(10);
                g.drawline(x2 + a, y2 + b, x2 + a, y2 + b);
            }
        }
    }
}

代码量也还是挺小的，因为是简单画板嘛~~

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