在Java AWT中绘制矩形

Question

I am interested in drawing a Rectangle object using AWT methods (I know, it's old). I have looked at other code on the forum that has answers, but they are not working for me. Here is what I am looking to do...

paint(Graphics g) {
    Rectangle r = new Rectangle(5,5,20,20);
    g.drawRect(r.getX(),r.getY(),r.getWidth(),r.getHeight());
}

But what I have to do is:

g.drawRect((int)r.getX().........);

and cast every value to an int. Am I doing something wrong? The code examples that I found have the solution without the casting. If I don't cast, I get an error. Surely, there should be something more simple.

Thanks in advance.

Answer 1

在javadoc中，我们可以看到这些方法返回一个双精度值，并且Graphics中的drawRect方法使用整数作为参数，如此处所述 ，因此您必须将double转换为整数。

Answer 2

You can cast Graphics to Graphics2D to use its draw() method to draw 'java.awt.shap' objects like this:

paint(Graphics g) {
   Grahpics2D g2 = (Graphics2D) g;
   Shape s = new Rectangle(5,5,20,20);
   g2.draw(s);
}

Answer 3

This is an easy way to do it. I figured it out:

paint(Graphics g) {
    Rectangle r = new Rectangle(5,5,30,30);
    g.drawRect(r.x,r.y,r.width,r.height);
}