لطفا منتظر باشید ...
16.2 A First Applet
Example 16-1 shows
what is probably the simplest possible applet you can write in Java.
Figure 16-1 shows the output it produces. This
example introduces the paint( ) method, which is
invoked by the applet viewer (or web browser) when the applet needs
to be drawn. This method should perform graphical outputsuch
as drawing text or lines or displaying imagesfor your applet.
The argument to paint( ) is a
java.awt.Graphics object that you use to do the
drawing.
Figure 16-1. A simple applet
Example 16-1. FirstApplet.java
package je3.applet;
import java.applet.*; // Don't forget this import statement!
import java.awt.*; // Or this one for the graphics!
/** This applet just says "Hello World" */
public class FirstApplet extends Applet {
// This method displays the applet.
public void paint(Graphics g) {
g.drawString("Hello World", 25, 50);
}
}
To display an applet, you need an HTML
file that references it. Here is an HTML fragment that can be used
with this first applet:
<applet code="je3.applet.FirstApplet.class"
codebase="../../"
width=150 height=100>
</applet>
With an HTML
file that references the applet, you can now view the applet with an
applet viewer or web browser. Note that the WIDTH
and HEIGHT attributes of this HTML tag are
required. For most applet examples in this book, I show only the Java
code, not the corresponding HTML file that goes with it. Typically,
that HTML file contains a tag as simple as the one shown here.
