java awt事件队列/调度线程未知源错误？

Question

我尝试运行此代码以使用 JFrame 制作图像

主类

import java.awt.*;
import javax.swing.JFrame;

public class main {

    public static void main(String[] args){
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setTitle("kek");

        f.add (new GraphicsSurface());

        f.setSize(512, 512);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}

GraphicsSurface类

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JComponent;

public class GraphicsSurface extends JComponent {

    public GraphicsSurface() {
    }

    public void paint (Graphics g) {
        int end = 0;
        long redint = 0, greenint = 0, blueint = 0;
        int xstart = 0, ystart = 0, xend = 0, yend = 0;
        double y = 0, x = 0;
        double width = 80;
        double angle = 0;
        double endpoint = 255;
        double curveintensitya = 1.4, curveintensityb = -0.9;
        double curvestarta = 30, curvestartb = 150;
        double curvelengtha = 15, curvelengthb = 30;
        double redvalue = 0, greenvalue = 0, bluevalue = 0;
        while (end == 0) {          

            Graphics2D g2d = (Graphics2D) g;            
            redvalue = 100 + (y / 2.56);
            greenvalue = 50 + (y / 1.28);
            bluevalue = 200 + (y / 5.12);
            redint = Math.round(redvalue);
            greenint = Math.round(greenvalue);
            blueint = Math.round(bluevalue);

            if (y >= curvestarta && y < (curvestarta + curvelengtha)) {
                angle = angle + (curveintensitya / curvelengtha);
            }
            if (y >= curvestartb && y < (curvestartb + curvelengthb)) {
                angle = angle + (curveintensityb / curvelengthb);
            }

            width = width + angle;
            if (width > 512) {
                width = 512;
            }
            x = Math.round(width);
            xend = (int) x;
            ystart = (int) y;
            yend = ystart;
            y = y + 1;

            if (y > endpoint) {
                end = 1;
            }

            g2d.setColor(new Color(redint, greenint, blueint, 255));

            g2d.drawLine(xstart, ystart, xend, yend);
        }
    }
}

但是我在控制台中得到了这个:

at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(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)

我想知道是什么原因导致了这个问题以及我应该采取什么措施来解决它。

Answer 1

问题出在这一行

g2d.setColor(new Color(redint, greenint, blueint, 255));

代码中的redint、greenint和blueint类型为long类型。但是 Color 的构造函数接受 int 或 long。

可以引用文档here

因此解决您的问题:将这些类型从 long 更改为 int 并进行适当的转换。