Hallo liebe Community,
ich wollte mal anfangen ein wenig mit der Geometrie in Java rumzuspielen, aber es gibt schon am anfang viele Probleme.
der Quellcode spuckt nur Fehler aus, aber ich weiß überhauptnicht warum, vielleicht bin ich auch absolut falsch rangegangen .
als Fehlermeldung erhalte ich:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at main.View$1.mouseReleased(View.java:55)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
vielen Dank im vorraus
mfg Thraex
ich wollte mal anfangen ein wenig mit der Geometrie in Java rumzuspielen, aber es gibt schon am anfang viele Probleme.
der Quellcode spuckt nur Fehler aus, aber ich weiß überhauptnicht warum, vielleicht bin ich auch absolut falsch rangegangen .
Java:
/*
* Created on 18.02.2011
*
* TODO To change the template for this generated file go to
* Window - Preferences - Java - Code Style - Code Templates
*/
package main;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.MouseInfo;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
/**
* @author Thraex
*
* TODO To change the template for this generated type comment go to
* Window - Preferences - Java - Code Style - Code Templates
*/
public class View extends JFrame
{
public View ()
{
super("Geo");
Graphics Grafik = getGraphics();
JPanel Platte = new JPanel();
Platte.setLayout(new FlowLayout());
Platte.addMouseListener(Mauswaechter);
setContentPane(Platte);
this.setSize(800,600);
this.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
public MouseListener Mauswaechter = new MouseAdapter()
{
Graphics Grafik = getGraphics();
Point p1,p2;
public void mousePressed (MouseEvent Ereignis)
{
p1 = MouseInfo.getPointerInfo().getLocation();
}
public void mouseReleased (MouseEvent Ereignis)
{
p2 = MouseInfo.getPointerInfo().getLocation();
Grafik.drawRect(p1.x,p1.y,p2.x,p2.y);
}
};
}
als Fehlermeldung erhalte ich:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at main.View$1.mouseReleased(View.java:55)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
vielen Dank im vorraus
mfg Thraex