如何更改小程序的颜色

Question

我需要为Uni创建的程序需要一些帮助。 问题是setColor和getColor方法不起作用，并且当我也想要它时，行也不会更改颜色。

我需要怎么做才能将线条的颜色更改为红色？

干杯

import java.awt.Color;
import java.awt.Point;
import javax.swing.JPanel;
import java.awt.*;

public class Shape extends JPanel {
static Point startPoint = new Point(0, 0);
Point controlPoint = new Point(0, 0);

Color colour = Color.BLACK;

public Shape() {
    this(startPoint);

}

public Shape(Point startPoint) {
    // initialise variable startPoint
    this.startPoint = startPoint;
    // execute methods setColour and setControlPoint
    setColor(colour);
    setControlPoint(controlPoint);
    // change startPoint
    startPoint.x = 50;
    startPoint.y = 50;

}

public void setColor(Color colour) {
    this.colour = colour;
    colour = Color.RED;
}

public Color getColor() {
    return colour;
}

public void setControlPoint(Point controlPoint) {
    controlPoint.x = 150;
    controlPoint.y = 150;
}

public void paintComponent(Graphics g) {
    super.paintComponents(g);
    g.setColor(colour);
    g.drawLine(startPoint.x, startPoint.y, controlPoint.x, controlPoint.y);
}

}

Answer 1

设置颜色后，您需要调用repaint（）

public void setColor(Color colour) {
    this.colour = colour;
    colour = Color.RED;

    // Repaint so the component uses the new color
    repaint();
}

Answer 2

或者，您可以摆脱setColor（）方法。

然后，您可以使用：

setForeground( colour );

控制要绘制的线条的颜色。

Graphics对象的颜色将被设置为前景色，因此您也可以摆脱：

g.setColor( colour );