當我更改窗口大小時，我想繪制一些隨機三角形并縮放它們。我有一個單獨的類MyTriangle擴展MyShape. 我也有兩個變量：scaleX和scaleY. 每當我嘗試將三角形x和y值相乘并更改窗口大小時，三角形就會變得瘋狂并突然消失。當我嘗試寫作時graphics.fillPolygon(new int[]{(int)(x1*scX),(int)(x2*scX)(int)(x3*scX)}, new int[]{(int)(y1*scY),(int)(y2*scY),(int)(y3*scY), 3);由于某種原因，我的窗口沒有任何反應。//from MyShape class://scX = window.getWidth()/(double)window.defaultWidth;//scY = window.getHeight()/ (double)window.defaultHeight;public class MyTriangle extends MyShape { int[] x; int[] y; public MyTriangle(int x1, int x2, int x3, int y1, int y2, int y3, int red, int green, int blue) { super(x1, x2, x3, y1, y2, y3, red, green, blue); this.x=new int[]{x1,x2,x3}; this.y=new int[]{y1,y2,y3}; } @Override protected void paintComponent(Graphics graphics) { super.paintComponent(graphics); for(int i = 0; i<3; i++){ x[i]=(int)(x[i]*scX); y[i]=(int)(y[i]*scY); } graphics.fillPolygon(x,y,3); }我應該怎么做才能讓它工作？像這樣的縮放適用于矩形和橢圓形。
2 回答
慕尼黑5688855
TA貢獻1848條經驗 獲得超2個贊
每次繪制時都會縮放它。因此，如果在您進行縮放后比例因子沒有設置為 1，那么每次繪制它時它都會變大或變小。在paintComponent 中創建新數組以傳遞縮放值但保留原始值。
*編輯
@Override
protected void paintComponent(Graphics graphics) {
int[] xS = new int[3];
int[] yS = new int[3];
super.paintComponent(graphics);
for(int i = 0; i<3; i++){
xS[i]=(int)(x[i]*scX);
yS[i]=(int)(y[i]*scY);
}
graphics.fillPolygon(xS,yS,3);
}
慕神8447489
TA貢獻1780條經驗 獲得超1個贊
由于您正在處理多邊形，因此最簡單的解決方案是利用 API 的現有功能，通過使用 aAffineTransform來更改輸出的比例
https://i.stack.imgur.com/e2vLR.gif
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame();
MyTriangle shape = new MyTriangle(50, 100, 0, 0, 100, 100, 0, 0, 0);
JSlider slider = new JSlider(0, 400);
slider.setValue(100);
frame.add(shape);
frame.add(slider, BorderLayout.SOUTH);
slider.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent arg0) {
double value = slider.getValue() / 100d;
shape.setScale(value);
}
});
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class MyTriangle extends JPanel {
int[] x;
int[] y;
double scX;
double scY;
public MyTriangle(int x1, int x2, int x3, int y1, int y2, int y3, int red, int green, int blue) {
this.x = new int[]{x1, x2, x3};
this.y = new int[]{y1, y2, y3};
scX = 1;
scY = 1;
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
public void setScale(double scale) {
scX = scale;
scY = scale;
repaint();
}
@Override
protected void paintComponent(Graphics graphics) {
super.paintComponent(graphics);
Graphics2D g2d = (Graphics2D) graphics.create();
AffineTransform at = AffineTransform.getScaleInstance(scX, scY);
g2d.setTransform(at);
g2d.fillPolygon(x, y, 3);
g2d.dispose();
}
}
}
我強烈建議您查看2D 圖形教程以獲取更多詳細信息
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