我有一个方法Image
,需要轮换Image
,将其存储在新变量中,然后返回新的public Image getImage() {
buffImage.createGraphics().rotate(direction);
return buffImage;
}
。这是我的尝试,图像似乎是空的或什么的。它只是没有显示在屏幕上:
buffImage.createGraphics().rotate(direction);
当我取出x
时,图像在屏幕上绘制就没问题了,当然也没有旋转。
答案 0 :(得分:3)
So, based on the example in this answer,您应该能够设计一种旋转方法,可以将源图像旋转给定数量的度,例如......
// Make sure you actually load some image and assign it to this
// variable, otherwise you will have a NullPointerException to
// deal with
private BufferedImage source;
public Image rotateBy(double degrees) {
// The size of the original image
int w = source.getWidth();
int h = source.getHeight();
// The angel of the rotation in radians
double rads = Math.toRadians(degrees);
// Some nice math which demonstrates I have no idea what I'm talking about
// Okay, this calculates the amount of space the image will need in
// order not be clipped when it's rotated
double sin = Math.abs(Math.sin(rads));
double cos = Math.abs(Math.cos(rads));
int newWidth = (int) Math.floor(w * cos + h * sin);
int newHeight = (int) Math.floor(h * cos + w * sin);
// A new image, into which the original can be painted
BufferedImage rotated = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = rotated.createGraphics();
// The transformation which will be used to actually rotate the image
// The translation, actually makes sure that the image is positioned onto
// the viewable area of the image
AffineTransform at = new AffineTransform();
at.translate((newWidth - w) / 2, (newHeight - h) / 2);
// And we rotate about the center of the image...
int x = w / 2;
int y = h / 2;
at.rotate(rads, x, y);
g2d.setTransform(at);
// And we paint the original image onto the new image
g2d.drawImage(source, 0, 0, null);
g2d.dispose();
return rotated;
}
答案 1 :(得分:0)
您可以使用Rotated Icon并在Icon
中显示JLabel
。
旋转图标是一个可重复使用的类,因此您无需担心将旋转代码添加到需要此功能的每个类中。