我刚刚在学校开始学习 Java，正在尝试自定义控件和图形。我目前正在研究图案锁，一开始一切都很好，但突然间它绘制不正确。我确实更改了一些代码，但是当我看到错误时，我立即将其更改回来(撤消，ftw)，但它仍然给我同样的错误。

问题是，当我重新绘制时，我的点的绘制方式会发生变化，即使它不应该......

这里有几张图片描述了我的意思: /image/o4p7K.jpg

希望这足够清楚，否则请留下评论而不是减分。

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.util.ArrayList;
import javax.swing.JPanel;

public class Lock extends JPanel
{
    class Line
    {
        //Properties
        public Point start;
        public Point end;
        public float thickness;
        public Color color = new Color(63, 152, 137);
        public Color highlightColor = new Color(73, 162, 147);
        public Color borderColor = Color.BLACK;


    public Line()
    {

    }

    public Line(Point start, Point end, float thickness)
    {
        this.start = start;
        this.end = end;
        this.thickness = thickness;
    }

    public Line(Point start, Point end, float thickness, Color color, Color borderColor, Color highlightColor)
    {
        this.start = start;
        this.end = end;
        this.thickness = thickness;
        this.color = color;
        this.borderColor = borderColor;
        this.highlightColor = highlightColor;
    }

    public void Draw(Graphics2D g)
    {
        //Set the line thickness
        g.setStroke(new BasicStroke(thickness));

        //Border
        g.setColor(borderColor);
        g.drawLine(start.x, start.y, end.x, end.y);

        //Highlight
        g.setStroke(new BasicStroke(thickness - 1));
        g.setColor(highlightColor);
        g.drawLine(start.x, start.y, end.x, end.y);

        //Base color
        g.setStroke(new BasicStroke(thickness - 2));
        g.setColor(color);
        g.drawLine(start.x, start.y, end.x, end.y);

        //Reset the line thickness
        g.setStroke(new BasicStroke(Lock.this.drawnLineThickness));
    }
}

//Properties
public Dimension gridSize = new Dimension(3, 3);
public Dimension pointSize = new Dimension(50, 50);
public boolean stealth = false;
public Color backgroundColor = new Color(255, 0, 0, 0); //Transparent
public float drawingLineThickness = 1;
public float drawnLineThickness = 12;
public Color drawingLineColor = new Color(0, 128, 128); //Teal
public Color drawnLineColor = new Color(63, 152, 137); //Teal like color
public Color drawnLineBorderColor = Color.BLACK;
public Color drawnLineHighlightColor = new Color(73, 162, 147); //Teal like color

private static final long serialVersionUID = 1L;
private ArrayList<Rectangle> Points = new ArrayList<Rectangle>();
private ArrayList<Line> Lines = new ArrayList<Line>();
private boolean Dragging, Done;
private Point LineStartPoint, LineEndPoint;
private Rectangle StartPoint;

class MouseEventHandler extends MouseAdapter
{
    @Override
    public void mousePressed(MouseEvent e)
    {
        if(!Done)
        {
            for(Rectangle Point : Points)
            {
                if(IsInCircle(new Point(e.getX(), e.getY()), Point))
                {
                    StartPoint = Point;

                    LineStartPoint = new Point(StartPoint.x + (StartPoint.width / 2), StartPoint.y + (StartPoint.height / 2));
                }
            }
        }
    }

    @Override
    public void mouseDragged(MouseEvent e) 
    {
        Dragging = true;
        LineEndPoint = new Point(e.getX(), e.getY());

        for(Rectangle Point : Points)
        {
            //If the mouse is within one of the points and it's not the start point
            if(IsInCircle(new Point(e.getX(), e.getY()), Point) && Point != StartPoint)
            {
                LineEndPoint = new Point(Point.x + (Point.width / 2), Point.y + (Point.height / 2));

                Line LineToAdd = new Line(LineStartPoint, LineEndPoint, drawnLineThickness, drawnLineColor, drawnLineBorderColor, drawnLineHighlightColor);
                if(CheckLines(LineToAdd))
                {
                    Lines.add(LineToAdd);
                    LineStartPoint = LineEndPoint;
                }
            }
        }

        Lock.this.repaint();
    }

    @Override
    public void mouseReleased(MouseEvent e) 
    {
        //If the Lines array size is more than 0, that means that a line has been created and the control should now be "locked"
        if(Lines.size() > 0)
        {
            Done = true; //We are now done and should not be able to add more lines.
        }

        //We are no longer dragging, so we set this to false, so that we won't be drawing a line on the control after we are done
        Dragging = false;

        //Update controls graphics
        Lock.this.repaint();
    }
}

public Lock()
{
    CreateGrid();

    addMouseListener(new MouseEventHandler());
    addMouseMotionListener(new MouseEventHandler());
}

public void paintComponent(Graphics oldG)
{
    super.paintComponent(oldG);

    //Create a Graphics2D object as this class has more options
    Graphics2D g = (Graphics2D) oldG;

    //Rendering hints: https://docs.oracle.com/javase/tutorial/2d/advanced/quality.html
    //Change render quality to be prettier
    g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);

    //Set the controls background color
    g.setColor(backgroundColor);
    g.fillRect(0, 0, getWidth(), getHeight());

    if(!stealth)
    {
        if(Dragging)
        {
            g.setStroke(new BasicStroke(3));
            g.setColor(new Color(0, 128, 128));
            g.drawLine(LineStartPoint.x, LineStartPoint.y, LineEndPoint.x, LineEndPoint.y);
        }

        for(Line Line : Lines)
        { 
            Line.Draw(g);
        }
    }

    for(Rectangle Point : Points)
    {
        //Outer ring (black)
        GradientPaint Black = new GradientPaint(Point.x, Point.y, new Color(24, 25, 24), Point.width, Point.height, new Color(14, 15, 14));
        g.setPaint(Black);
        g.fill(new Ellipse2D.Double(Point.x, Point.y, Point.width, Point.height));

        //Outer ring highlight
        g.setColor(new Color(255, 255, 255, 20));
        g.draw(new Ellipse2D.Double(Point.x + 1, Point.y + 1, Point.width - 3, Point.height - 3));

        //Inner ring (teal)
        GradientPaint Teal = new GradientPaint(Point.x + (Point.width / 4) - 1, Point.y + (Point.height / 4) - 1, new Color(63, 152, 137), Point.width / 2 + 3, Point.height / 2 + 3, new Color(0, 128, 128));
        g.setPaint(Teal);
        g.fill(new Ellipse2D.Double(Point.x + (Point.width / 4) - 1, Point.y + (Point.height / 4) - 1, Point.width / 2 + 3, Point.height / 2 + 3));

        //Inner ring highlight
        g.setColor(new Color(0, 0, 0));
        g.draw(new Ellipse2D.Double(Point.x + (Point.width / 4) - 1, Point.y + (Point.height / 4) - 1, Point.width / 2 + 3, Point.height / 2 + 3));
        g.setColor(new Color(255, 255, 255, 30));
        g.draw(new Ellipse2D.Double(Point.x + (Point.width / 4) - 2, Point.y + (Point.height / 4) - 2, Point.width / 2 + 4, Point.height / 2 + 4));
    }
}

//Method is used to check whether a point is inside a rectangle/circle
private boolean IsInCircle(Point MouseLocation, Rectangle Rectangle)
{
  boolean Result;

  //Get center of rectangle/circle
  Point CenterPoint = new Point(Rectangle.x + (Rectangle.width / 2), Rectangle.y + (Rectangle.height / 2));

  //Get distance from centerpoint to mouselocation
  int DistanceX = Math.abs(CenterPoint.x - MouseLocation.x);
  int DistanceY = Math.abs(CenterPoint.y - MouseLocation.y);

  //The distance squared
  int DistanceSquared = (int) Math.sqrt(DistanceX * DistanceX + DistanceY * DistanceY);

  //The radious 
  int Radius = Rectangle.width / 2;

  //If the radious is more or equal to the distance squared, the point is inside the circle
  Result = Radius >= DistanceSquared;

  return Result;
}

//Method is used to check whether a line has previously been drawn to a specific point
private boolean CheckLines(Line Line)
{
  boolean Result = true;

  for(Line _Line : Lines)
  {
    //If a point has previously been drawn to, return false to not make it possible to draw another line to that point
    if(_Line.end.getX() == Line.end.getX() && _Line.end.getY() == Line.end.getY() || _Line.start.getX() == Line.start.getX() && _Line.start.getY() == Line.start.getY())
    {
      Result = false;
    }
  }

  //Same idea as above
  if(Lines.contains(Line))
  {
    Result = false;
  }

  return Result;
}

//Method is used to generate a grid of points
private void CreateGrid()
{
    int X = 0, Y = 0, ControlHeight = 0;

    for(int i = 0; i < gridSize.width; i++)
    {
        for(int ii = 0; ii < gridSize.height; ii++)
        {
            Points.add(new Rectangle(X, Y, pointSize.width, pointSize.height));

            Y += pointSize.height * 2;

            ControlHeight = Y;

            if(ii == gridSize.height - 1)
            {
                Y = 0;
            }
        }

        X += pointSize.width * 2;
    }

    this.setMinimumSize(new Dimension(X - pointSize.width + 1, ControlHeight - pointSize.height + 1));
    this.setMaximumSize(new Dimension(X - pointSize.width + 1, ControlHeight - pointSize.height + 1));
    this.setSize(new Dimension(X - pointSize.width + 1, ControlHeight - pointSize.height + 1));
}

//Method is used to get the current pattern code as a string
public String GetPattern()
{
    String Result = "";

    for(Line Line : Lines)
    { 
        Result += Line.start.toString() + ";" + Line.end.toString() + ": \n";
    }

    return Result;
}

//Method is used to clear the current pattern
public void ClearPattern()
{
    //Clear the lines
    Lines.clear();

    //Reset the * 
    Done = false;

    //Repaint the control to show that there no longer are any lines.
    this.repaint();
}

}

最佳答案

我发现了问题......

这行代码就是问题所在。 BasicStroke 值不是我输入的原始值 (c+p)，而是接近名称的值。

//重置线条粗细
g.setStroke(new BasicStroke(Lock.this.drawnLineThickness));

我通过将代码更正为原始代码来修复它:

//重置线条粗细
g.setStroke(new BasicStroke(Lock.this.drawingLineThickness));

关于Java自定义控件重绘导致绘制不正确(不同)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31805527/