如何调用Applet的扩展类中的paint方法？ [英] How to call a paint method inside Applet extended class?

问题描述

我有2类文件名为PaintMe.java和Starter.java。
PaintMe.java包括：

 进口java.applet.Applet中;
进口java.awt中的*。公共类PaintMe扩展的Applet {
    公共无效漆（图形G）{
        g.setColor（Color.red）;
        g.drawString（HELLOOO，15，25）;
    }
}
 

Starter.java包括：

 进口java.applet.Applet中;
进口java.awt.Graphics;
公共类起动器{
    公共静态无效的主要（字串[] args）{
        PaintMe圈=新PaintMe（）;
        ring.paint（）;
    }
}
 

所以问题是，我怎么能画我的字符串调用从Starter.java油漆的方法？

解决方案

要得到它来编译，更改

  ring.paint（）;
 

...到...

  ring.repaint（）;
 

---

注释

1. 请不要在这千年的使用AWT code。使用Swing（它提供了一个 JApplet的 ）。


2. 请不要开始从applet的主（字符串[]）。 Applet是由JRE启动时，它被嵌入在一个网页（或推出了采用 JWS ）。的GUI可以在一个面板进行设计，即再放入一个自由浮动的应用程序或小应用程序。即称为混合。但无论框架和小程序分别添加了图形用户界面，这是（最常见），不同的类要么。


3. ，因为它的存在主要是没用的。除非小程序被添加到一个容器中，可见，在code将成功运行，但在稍后结束而不显示任何内容。

---

更新1

  

..试过了，但它仍然没有吸取我的字符串中的小程序窗口。

试试这个。

来源

  //＆LT;小程序code ='PaintMeWIDTH = 300 HEIGHT = 50＆GT;＆LT; /小程序＆GT;
进口java.applet.Applet中;
进口java.awt中的*。公共类PaintMe扩展的Applet {
    公共无效漆（图形G）{
        g.setColor（Color.red）;
        g.drawString（HELLOOO，15，25）;
    }
}
 

提示

 ＆GT; javac的PaintMe.java
＆GT; appletviewer中PaintMe.java
 

屏幕截图

---

更新2

  

..我需要把它从Starter.java类开始。

我认为这是一个愚蠢的要求，好像JWS（如前所述＆放大器;注释中的链接）发起，查看这个GUI一个的JFrame 是最好的方式。 OTOH，这里是一个（非常）天真实施起动机类，它会显示在屏幕上的小程序。

它混合AWT和Swing（坏），它并不试图实施任何形式的applet上下文的，并且不调用该applet 的init / 启动 / 停止 / 摧毁方法，但也足以让applet的导通屏幕从其它类。

 进口java.awt.Dimension中;
进口javax.swing.JOptionPane中;公共类起动器{
    公共静态无效的主要（字串[] args）{
        PaintMe圈=新PaintMe（）;
        ring.set preferredSize（新尺寸（250,30））;
        JOptionPane.showMessageDialog（NULL，环）;
    }
}
 

I have 2 class files called PaintMe.java and Starter.java. PaintMe.java contains:

import java.applet.Applet;
import java.awt.*;

public class PaintMe extends Applet {
    public void paint(Graphics g) {
        g.setColor(Color.red);
        g.drawString("HELLOOO", 15, 25);
    }
}

Starter.java contains:

import java.applet.Applet;
import java.awt.Graphics;


public class Starter {
    public static void main(String[] args) {
        PaintMe ring = new PaintMe();
        ring.paint();
    }
}

So question is, how can I paint my string with calling a paint method from Starter.java?

解决方案

To get it to compile, change

ring.paint();

..to..

ring.repaint();

---

Notes

1. Don't code using AWT in this millennium. Use Swing (which offers a JApplet).
2. Don't start an applet from the main(String[]). An applet is started by the JRE when it is embedded in a web page (or launched using JWS). A GUI can be designed in a panel, that is then put in a free-floating application or applet. That is known as a hybrid. But both frame and applet separately add the GUI, which is (most often) a different class to either.
3. The main as it exists is useless. Unless the applet is added to a container and made visible, the code will run successfully but end in a few moments without displaying anything.

---

Update 1

..tried that, but it still doesn't draw my string in the applet window.

Try this.

Source

// <applet code='PaintMe' width=300 height=50></applet>
import java.applet.Applet;
import java.awt.*;

public class PaintMe extends Applet {
    public void paint(Graphics g) {
        g.setColor(Color.red);
        g.drawString("HELLOOO", 15, 25);
    }
}

Prompt

> javac PaintMe.java
> appletviewer PaintMe.java

Screenshot

---

Update 2

..I need to have it started from Starter.java class.

I think that is a silly requirement, and it seems like JWS (as mentioned & linked in comments) launching a JFrame is the best way to view this GUI. OTOH, here is a (very) naive implementation of the Starter class that will show that applet on-screen.

It mixes AWT and Swing (bad), it does not attempt to implement any sort of applet context, and does not call the applet init/start/stop/destroy methods, but is enough to get the applet on-screen from another class.

import java.awt.Dimension;
import javax.swing.JOptionPane;

public class Starter {
    public static void main(String[] args) {
        PaintMe ring = new PaintMe();
        ring.setPreferredSize(new Dimension(250,30));
        JOptionPane.showMessageDialog(null, ring);
    }
}

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