我的applet代码编译得很好，但是，每次都收到“Applet Started”消息。请不要劝阻我使用AWT或Applet。我只是想完成我的任务。目前，我的代码是：
主要方法
import java.awt.*;
import java.awt.event.*;
public class Lab33ast
{
public static void main(String[] args)
{
Frame frame = new Frame("Lab33ast");
frame.add(new GfxApp());
frame.setSize(100, 750);
frame.addWindowListener(new WindowAdapter() {public void
windowClosing(WindowEvent e) {System.exit(0);}});
frame.setVisible(true);
}
}
接下来，我在一个单独的文件中有一个paint方法。 GfxApp
import java.awt.*;
public class GfxApp extends Panel
{
private int td = 200; //Time Delay on graphics
public void paint(Graphics g)
{
g.setFont(new Font("Arial", Font.BOLD, 28));
g.drawString("Lab 33A 80/100 POINT VERSUIN", 300, 50);
g.setFont(new Font("Arial", Font.BOLD, 20));
g.drawString("DRAWING A LINKED LIST AS A STACK", 50, 215);
g.drawString("DRAWING A LINKED LIST AS A QUEUE", 50, 415);
drawStack(g);
drawQueue(g);
}
public void drawStack(Graphics g)
{
g.setFont(new Font("ARIAL", Font.BOLD, 20));
}
public void drawQueue(Graphics g)
{
g.setFont(new Font("ARIAL", Font.BOLD, 20));
}
}
接下来，我有一个名为GfxNode的文件，我们的老师告诉我们在没有进一步指示的情况下添加。
import java.awt.*;
public class GfxNode
{
private int x; // x coordinate of node
private int y; // y coordinate of node
private final int width; // width of the gfx node
private final int height; // heigth of the gfx node
private final int time; // delay time between displays
// GfxNode constructor instantiates an object and
// stores its Top-Left coordinate (tlx,tly) information, as
// well as the length and width of the node object. A node object
// with two fields is drawn at the specified coordinate.
public GfxNode(Graphics g, int tlx, int tly, char ltr, int clr, int dt)
{
x = tlx;
y = tly;
width = 30;
height = 15;
time = dt;
drawNode(g,clr);
drawPointer(g,ltr,1,clr);
}
// Method drawNode is a private helper method to draw linked list nodes.
// This method draws a node with two fields at a location of the
// Top-Left coordinate information in the current object.
private void drawNode(Graphics g, int clr)
{
g.setColor(getColor(clr));
g.drawRect(x,y,width,height);
g.drawLine(x+height,y,x+height,y+height);
delay(time);
}
// Method getColor a private helper method to make it easier to use colors
// in a graphics program.
private Color getColor(int clr)
{
Color temp = Color.white;
switch (clr)
{
case 0: temp = Color.black; break;
case 1: temp = Color.red; break;
case 2: temp = Color.green; break;
case 3: temp = Color.blue; break;
case 4: temp = Color.orange; break;
case 5: temp = Color.cyan; break;
case 6: temp = Color.magenta; break;
case 7: temp = Color.yellow; break;
case 8: temp = Color.pink; break;
case 9: temp = Color.white; break;
}
return temp;
}
// Method getX returns the top-left X-coordinate of a linked list node.
public int getx()
{
return x;
}
// Method getY returns the top-left Y-coordinate of a linked list node.
public int gety()
{
return y;
}
// Method drawPointer draws a vertical pointer down to an existing node.
// The first pointer to a node uses OffSet value 1 and the second
// pointer to the same node uses OffSet value 2. The result is that
// the second pointer is moved farther to the right.
public void drawPointer(Graphics g, char ltr, int offSet, int clr)
{
if (offSet == 1)
offSet = 8;
else
offSet = 18;
int x1 = x + offSet;
int y1 = y - 20;
int x2 = x1;
int y2 = y - 2;
g.setColor(getColor(clr));
g.drawLine(x1,y1,x2,y2);
g.drawLine(x2,y2,x2-3,y2-3);
g.drawLine(x2,y2,x2+3,y2-3);
drawLetter(g,ltr,x+offSet-4,y-32);
delay(time);
}
// Method enterData draws a letter in the Data field of the GfxNode.
public void enterData(Graphics g, char ltr, int clr)
{
g.setColor(getColor(clr));
drawLetter(g,ltr,x+3,y+3);
delay(time);
}
// Method drawLink draws a link from the current sourceNode to the
// endNode in the specified color (clr).
public void drawLink(Graphics g, GfxNode endNode, int clr)
{
int x1,x2;
int y1 = this.gety() + height/2;
int y2 = endNode.gety() + height/2;
g.setColor(getColor(clr));
if (this.getx() < endNode.getx())
{
x1 = this.getx() + 22;
x2 = endNode.getx() - 2;
g.drawLine(x1,y1,x2,y2);
g.drawLine(x2,y2,x2-3,y2-3);
g.drawLine(x2,y2,x2-3,y2+3);
}
else
{
x1 = endNode.getx() + 8;
x2 = this.getx() + width + 2;
g.drawLine(x1,y1,x2,y2);
g.drawLine(x1,y1,x1-3,y1-3);
g.drawLine(x1,y1,x1-3,y1+3);
}
delay(time);
}
// Method drawNull draws a diagonal g.drawLine in the Next
// field of a list node, to indicate a NULL value.
public void drawNull(Graphics g, int clr)
{
g.setColor(getColor(clr));
g.drawLine(x+height+1,y+1,x+width-1,y+height-1);
delay(time);
}
// Method drawLetter upper-case Letter characters. The characters
// are drawn in a 9x9 pixel box.
// The (x,y) parameters indicate the coordinate of the top-left corner
// of the box. Only capital letters and numbers are drawn.
public void drawLetter(Graphics g, char ltr, int x, int y)
{
switch (ltr)
{
case 'A' :
g.drawLine(x,y,x,y+8);
g.drawLine(x+8,y,x+8,y+8);
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+4,x+8,y+4);
break;
case 'B' :
g.drawLine(x,y,x,y+8);
g.drawLine(x,y,x+5,y);
g.drawLine(x,y+8,x+5,y+8);
g.drawLine(x,y+4,x+5,y+4);
g.drawLine(x+5,y,x+8,y+2);
g.drawLine(x+5,y+8,x+8,y+6);
g.drawLine(x+5,y+4,x+8,y+2);
g.drawLine(x+5,y+4,x+8,y+6);
break;
case 'C' :
g.drawLine(x,y,x,y+8);
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+8,x+8,y+8);
break;
case 'D' :
g.drawLine(x,y,x,y+8);
g.drawLine(x,y,x+4,y);
g.drawLine(x,y+8,x+4,y+8);
g.drawLine(x+4,y,x+8,y+4);
g.drawLine(x+4,y+8,x+8,y+4);
break;
case 'E' :
g.drawLine(x,y,x,y+8);
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+8,x+8,y+8);
g.drawLine(x,y+4,x+6,y+4);
break;
case 'F' :
g.drawLine(x,y,x,y+8);
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+4,x+6,y+4);
break;
case 'G' :
g.drawLine(x,y,x,y+8);
g.drawLine(x,y,x+6,y);
g.drawLine(x,y+8,x+8,y+8);
g.drawLine(x+8,y+8,x+8,y+4);
g.drawLine(x+8,y+4,x+4,y+4);
break;
case 'H' :
g.drawLine(x,y,x,y+8);
g.drawLine(x+8,y,x+8,y+8);
g.drawLine(x,y+4,x+8,y+4);
break;
case 'I' :
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+8,x+8,y+8);
g.drawLine(x+4,y,x+4,y+8);
break;
case 'J' :
g.drawLine(x+8,y,x+8,y+8);
g.drawLine(x,y+8,x+8,y+8);
g.drawLine(x,y+8,x,y+4);
break;
case 'K' :
g.drawLine(x,y,x,y+8);
g.drawLine(x+8,y,x+1,y+4);
g.drawLine(x+8,y+8,x+1,y+4);
break;
case 'L' :
g.drawLine(x,y,x,y+8);
g.drawLine(x,y+8,x+8,y+8);
break;
case 'M' :
g.drawLine(x,y,x,y+8);
g.drawLine(x+8,y,x+8,y+8);
g.drawLine(x,y,x+5,y+5);
g.drawLine(x+8,y+1,x+4,y+4+1);
break;
case 'N' :
g.drawLine(x,y,x,y+8);
g.drawLine(x+8,y,x+8,y+8);
g.drawLine(x,y,x+9-1,y+8);
break;
case 'O' :
g.drawLine(x,y,x,y+8);
g.drawLine(x+8,y,x+8,y+8);
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+8,x+8,y+8);
break;
case 'P' :
g.drawLine(x,y,x,y+8);
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+4,x+8,y+4);
g.drawLine(x+8,y,x+8,y+4);
break;
case 'Q' :
g.drawLine(x,y,x,y+8);
g.drawLine(x+8,y,x+8,y+8);
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+8,x+8,y+8);
g.drawLine(x+3,y+5,x+8,y+10);
break;
case 'R' :
g.drawLine(x,y,x,y+8);
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+4,x+8,y+4);
g.drawLine(x+8,y,x+8,y+4);
g.drawLine(x,y+4,x+9,y+8);
break;
case 'S' :
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+4,x+8,y+4);
g.drawLine(x,y+8,x+8,y+8);
g.drawLine(x,y,x,y+4);
g.drawLine(x+8,y+4,x+8,y+8);
break;
case 'T' :
g.drawLine(x,y,x+8,y);
g.drawLine(x+4,y,x+4,y+8);
break;
case 'U' :
g.drawLine(x,y,x,y+8);
g.drawLine(x+8,y,x+8,y+8);
g.drawLine(x,y+8,x+8,y+8);
break;
case 'V' :
g.drawLine(x,y,x+4,y+8);
g.drawLine(x+8,y,x+4,y+8);
break;
case 'W' :
g.drawLine(x,y,x,y+8);
g.drawLine(x+8,y,x+8,y+9-1);
g.drawLine(x,y+8,x+4,y+4);
g.drawLine(x+8,y+8,x+4,y+4);
break;
case 'x' :
g.drawLine(x,y,x+9,y+8);
g.drawLine(x,y+8,x+8,y);
break;
case 'y' :
g.drawLine(x,y,x+5-1,y+4);
g.drawLine(x+8,y,x+4,y+4);
g.drawLine(x+4,y+4,x+4,y+8);
break;
case 'Z' :
g.drawLine(x,y,x+8,y);
g.drawLine(x,y+8,x+8,y+8);
g.drawLine(x+8,y,x,y+8);
break;
default :
g.fillRect(x,y,8,8);
}
}
// Method delay allows viewing the sequence in which the linked lists are drawn/
private void delay(double n)
{
for (double k = 1; k < n; k+=0.00001);
}
}
我不知道上面的代码是什么或它与我的目标的关系。随意向我解释。
我创建了另一个名为GfxApplet的类，并指向.htm代码。
import java.awt.*;
import java.awt.event.*;
import java.applet.Applet;
public class GfxApplet extends Applet
{
@Override
public void init()
{
super.init();
GfxApp app = new GfxApp();
add(app);
}
}
我的HTML
<html>
<head>
</head>
<body bgcolor="000000">
<center>
<applet
code = "Lab33ast.class"
width = "500"
height = "300"
>
</applet>
</center>
</body>
</html>
如果有人能提供具体而详细的解决方案，我将非常感激。
答案 0 :(得分：1)
代码中没有Applet（没有任何内容来自Applet）。
一般来说，你应该从一个不同的容器类开始，也许Panel（因为你生活在AWT的黑暗时代），把你所有的逻辑都放在这个类中。
然后，当您需要它时，创建一个Frame的实例或创建一个从Applet扩展的类，并向其添加一个面板实例。
除非你有一个主要的驱动因素，否则我会避免以这种方式直接使用AWT并使用Swing，Swing取代了16年前的AWT，因此你可能会得到更好的社区支持。有关详细信息，请参阅Creating a GUI With JFC/Swing
由于现在大多数浏览器都会主动阻止applet，我也会在这里质疑它们的使用
错过“请不要阻止我使用AWT或小程序”免责声明
我看到了扩展applet的逻辑。我只是不知道在哪里放置“扩展Applet”部分。当我改变从GfxApp扩展的内容时，我在main方法中收到很多错误，最常见的是“gfx.addWindowListener（new WindowAdapter（）”。我的IDE说它找不到符号
将核心逻辑移至基于Panel的班级
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Panel;
public class GfxApp extends Panel {
private int td = 200; //Time Delay on graphics
public void paint(Graphics g) {
g.setFont(new Font("Arial", Font.BOLD, 28));
g.drawString("Lab 33A 80/100 POINT VERSUIN", 300, 50);
g.setFont(new Font("Arial", Font.BOLD, 20));
g.drawString("DRAWING A LINKED LIST AS A STACK", 50, 215);
g.drawString("DRAWING A LINKED LIST AS A QUEUE", 50, 415);
drawStack(g);
drawQueue(g);
}
public void drawStack(Graphics g) {
g.setFont(new Font("ARIAL", Font.BOLD, 20));
}
public void drawQueue(Graphics g) {
g.setFont(new Font("ARIAL", Font.BOLD, 20));
}
}
从extends创建一个Applet的类，向其添加GfxApplet的实例...
import java.applet.Applet;
public class GfxApplet extends Applet {
@Override
public void init() {
super.init();
GfxApp app = new GfxApp();
add(app);
}
}
将applet html代码更改为指向它...
<html>
<head>
</head>
<body bgcolor="000000">
<center>
<applet
code = "GfxApplet.class"
width = "500"
height = "300"
>
</applet>
</center>
</body>
</html>
如果您需要，可以在需要时将GfxApp添加到Frame的实例中。
public static void main(String[] args) {
Frame frame = new Frame("Lab33ast");
frame.add(new GfxApp());
frame.setSize(100, 750);
frame.addWindowListener(new WindowAdapter() {
public void
windowClosing(WindowEvent e) {
System.exit(0);
}
});
frame.setVisible(true);
}
这是良好管理UI代码的基础