多的Graphics2D对象
-
19-09-2019 - |
题
我有JPanel的Graphics对象并且工作正常:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Rectangle2D;
import javax.swing.JPanel;
public class GraphicsTest extends JPanel
{
private Graphics2D g2d;
private String state;
private int x, y;
@Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g2d = (Graphics2D) g;
g2d.setClip(0, 0, getWidth(), getHeight());
g2d.setColor(Color.BLACK);
g2d.drawString("STATE: " + state, 5, 15);
g2d.drawString("Mouse Position: " + x + ", " + y, 5, 30);
g2d.setColor(Color.red);
Rectangle2D r2d = new Rectangle2D.Double(x,y,10,10);
g2d.draw(r2d);
Test t = new Test();
super.add(t);
repaint();
}
public void setState(String state) { this.state = state; }
public String getState() { return state; }
public void setX(int x) { this.x = x; }
public void setY(int y) { this.y = y; }
}
我是一个新的图形组件实验,当我实例化一个新的测试和GraphicsTest添加它没有任何反应。它是什么,我做错了吗?
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Rectangle2D;
import javax.swing.JComponent;
public class Test extends JComponent
{
private Graphics2D g2d;
private String state;
private int x, y;
@Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g2d = (Graphics2D) g.create();
g2d.setColor(Color.GREEN);
g2d.fill(new Rectangle2D.Double(60, 60,
10, 10));
repaint();
}
public void setState(String state) { this.state = state; }
public String getState() { return state; }
public void setX(int x) { this.x = x; }
public void setY(int y) { this.y = y; }
}
谢谢!
解决方案
您应该添加测试部件只有一次,并设置一个布局:
public GraphicTest()
{
super();
setLayout(new BorderLayout());
add(new Test(),BorderLayout.CENTER);
}
另外,不要保存Graphics2D
对象,因为一旦paintComponent
完成,不叫里面repaint
paintComponent
他们将是无效的。使用计时器如果需要在更改组件的外观repaint
方法动画和呼叫setXXX
。
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