我需要創建一個名爲「TriangleShape」的類,它可以實現java.awt.Shape。 現在另一個類「TriangleComponent」應該有一個TriangleShape類的對象,它應該繪製一個三角形,並且具有給定的邊長。Java - 製作三角類
我設法創建它,但我讀過的三角形應以下列方式得出:
TriangleShape t = new TriangleShape(30,40,50);
g2.draw(t); //This is the Graphics2D object that I use in paintComponent
下面是我創建的代碼,但它使用的Line2D創建一個三角形。 這是TriangleShape類,假設我已經實現了Shape類的所有方法。
public class TriangleShape implements java.awt.Shape{
private double a, b, c;
private int x,y;
private Point2D loc;
public TriangleShape() {
this.a=0;
this.b=0;
this.c=0;
}
public TriangleShape(double a, double b, double c) {
//if supplied dimensions form a valid Triangle
if (this.isValid(a,b,c)) {
this.a = a;
this.b = b;
this.c = c;
}
//Otherwise make it zero sized triangle
else{
this.a=0;
this.b=0;
this.c=0;
}
}
public void resize(double a, double b, double c) {
if (this.isValid(a,b,c)) {
this.a = a;
this.b = b;
this.c = c;
}
//else let size remain unchanged
}
public TriangleShape getRandomTriangle() {
TriangleShape t = new TriangleShape(5,8,9);
return t;
}
public double area(){
double area, s;
s = (a+b+c)/2;
area = Math.sqrt(s *(s-a) * (s-b) * (s-c));
return area;
}
private boolean isValid(double a, double b, double c) {
double s = (a+b+c)/2;
if (((s-a) * (s-b) * (s-c)) <= 0)
return false;
else
return true;
}
public double perimeter() {
double p;
p = a+b+c;
return p;
}
public double getA(){
return a;
}
public double getB(){
return b;
}
public double getC(){
return c;
}
public void setLocation(Point2D location){
loc = location;
}
public Point2D getLocation(){
return loc;
}
public double getX(){
return loc.getX();
}
public double getY(){
return loc.getY();
}
而且TriangleComponent類:
public class TriangleComponent extends JComponent{
TriangleShape t;
double alpha, beta, gamma;
double a,b,c;
double X,Y;
@Override
protected void paintComponent(Graphics g) {
//super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
t = new TriangleShape(100,100,190);
t.setLocation(new Point2D.Double(100,500));
a = t.getA();
b = t.getB();
c = t.getC();
X = t.getX();
Y = t.getY();
///////////////Drawing Base line.....
g2.draw(new Line2D.Double(X,Y,(X+c),Y)); //line c...
g2.draw(new Line2D.Double((X+c), Y, ((X+c)+a*Math.cos(Math.PI+getBeta())), (Y+a*Math.sin(Math.PI+getBeta())))); //line a...
//JOIning the last end points
g2.draw(new Line2D.Double(X, Y, ((X+c)+a*Math.cos(Math.PI+getBeta())), (Y+a*Math.sin(Math.PI+getBeta()))));
System.out.println("X1 = "+X+" Y1 = "+Y);
System.out.println("X2 = "+(X+c)+" Y2 = "+Y);
System.out.println("X3 = "+((X+c)+a*Math.cos(Math.PI+getBeta()))+" Y3 = "+ (Y+a*Math.sin(Math.PI+getBeta())));
//System.out.println("Alpha = "+getAlpha());
System.out.println("Gamma = "+(getGamma()*180)/Math.PI);
}
public double getAlpha(){
double temp = Math.acos(((Math.pow(c, 2)+Math.pow(b, 2))-Math.pow(a, 2))/(2*b*c));
System.out.println("Alpha = "+temp+" Degrees");
return temp;
}
public double getBeta(){
double temp = Math.acos(((Math.pow(c, 2)+Math.pow(a, 2))-Math.pow(b, 2))/(2*a*c));
System.out.println("Beta = "+temp+" Degrees");
return (temp);// * Math.PI)/180;
}
public double getGamma(){
double temp = Math.acos(((Math.pow(a, 2)+Math.pow(b, 2))-Math.pow(c, 2))/(2*b*a));
System.out.println("Gamma = "+temp+" Degrees");
return (temp);// * Math.PI)/180;
}
}
這工作,但我需要一種方法來繪製三角形,而不依賴於Graphics2D
或直接與paintComponent
方法繪製它。有沒有辦法做到這一點?
但是,因爲我們必須在getPathIterator方法中返回PathIterator,所以如何將Path2D轉換爲PathIterator? 順便說一句,非常感謝您的回覆。 – Jaydeep 2012-02-27 10:49:29
由於Path2D類實現了Shape接口,它也有一個[getPathIterator方法](http://docs.oracle.com/javase/6/docs/api/java/ AWT/GEOM/Path2D.Float.html#的getPathIterator(java.awt.geom.AffineTransform中))。您可以簡單地從您自己的班級委派給該方法。 – Jiddo 2012-02-27 15:51:23
夥計,你該死的天才! 非常感謝! – Jaydeep 2012-02-27 20:34:23