Java &引用;“线程中的异常”;动画线程“;在Eclipse中使用处理时出错
我用类在eclipse中创建了一个非常简单的处理草图。eclipse说代码没有错误,只有警告,但在运行时失败,控制台显示以下错误:Java &引用;“线程中的异常”;动画线程“;在Eclipse中使用处理时出错,java,eclipse,class,exception,processing,Java,Eclipse,Class,Exception,Processing,我用类在eclipse中创建了一个非常简单的处理草图。eclipse说代码没有错误,只有警告,但在运行时失败,控制台显示以下错误: Exception in thread "Animation Thread" java.lang.NullPointerException at processing.core.PApplet.ellipse(PApplet.java:12174) at assignment.Tracking.display(Tracking.java:15) at assignm
Exception in thread "Animation Thread" java.lang.NullPointerException
at processing.core.PApplet.ellipse(PApplet.java:12174)
at assignment.Tracking.display(Tracking.java:15)
at assignment.Assignment.draw(Assignment.java:16)
at processing.core.PApplet.handleDraw(PApplet.java:2386)
at processing.core.PGraphicsJava2D.requestDraw(PGraphicsJava2D.java:240)
at processing.core.PApplet.run(PApplet.java:2256)
at java.lang.Thread.run(Unknown Source)
代码如下:
package assignment;
import processing.core.*;
public class Assignment extends PApplet {
Tracking tracking;
public void setup() {
size(500, 500);
tracking = new Tracking();
}
public void draw() {
tracking.display();
}
}
跟踪类的代码为:
package assignment;
import processing.core.*;
public class Tracking extends PApplet
{
int test;
public Tracking() {
test = 100;
}
void display(){
ellipse(test, test, test, test);
}
}
我相信我已经导入了必要的processing.jar文件。提前感谢您的帮助问题似乎是您在
作业
类中进行设置,但从跟踪
类调用椭圆()
。请注意,Assignment
和Tracking
是两个不同的PApplet
s。在分配
中调用大小(500500)
,但是跟踪
没有定义大小