半透明のフレームを持ち、ユーザーが望む場所に線を描画する単純なアプリを構築しようとしています.マウスイベントをキャッチするリスナーも追加しましたが、これらはそれに応じて表示されます.すべて正常に動作していますが、問題は次のとおりです: 1)ウィンドウは透明ではありません 2) 完全に黒く、線が白く見えます。
誰でもできますか ここにコードがあります：
import java.awt.Color;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class MouseListen2 extends JFrame implements MouseListener {
String str = "Nothing";
int x[][] = new int[100][2];
int count = 0;
int flag = 1;
boolean draw = false;
MouseListen2() {
super("Line Draw App");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(400, 300);
this.addMouseListener(this);
setBackground(new Color(0, 0, 0, 0));
JPanel jp = new JPanel() {
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
Paint gp = new GradientPaint(300, 700, new Color(20, 20, 210, 0), 100, 00, new Color(10, 20, 40, 255));
g2.setPaint(gp);
g2.fillRect(0, 0, getWidth(), getHeight());
}
};
setContentPane(jp);
setVisible(true);
//c.setOpaque(true);
}
public void paint(Graphics g) {
//Graphics g=this.getGraphics();
//super.paint(g);
Graphics2D g2 = (Graphics2D) g;
g2.clearRect(0, 0, getWidth(), getHeight());
g2.drawString(str, 50, 50);
//initially count=0 hence i<-1 so loop will not automatically run in the beginning
for (int i = 0; i < count - 1; i = i + 2) {
g2.drawLine(x[i][0], x[i][1], x[i + 1][0], x[i + 1][1]);
}
//repaint(); using this here creates an infinite loop as after mouse event paint is called and at the end
//this method is again called using the repaint() and so on the loop continues.
}
public static void main(String[] args) {
JFrame.setDefaultLookAndFeelDecorated(true);
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new MouseListen2();
}
});
}
@Override
public void mouseClicked(MouseEvent e) {
str = "clicked";
repaint();
}
@Override
public void mousePressed(MouseEvent e) {
str = "pressed";
repaint();
x[count][0] = e.getX();
x[count][1] = e.getY();
count++;
}
@Override
public void mouseReleased(MouseEvent e) {
str = "released";
draw = true;
x[count][0] = e.getX();
x[count][1] = e.getY();
count++;
//draw();
repaint();
}
@Override
public void mouseEntered(MouseEvent e) {
str = "entered";
repaint();
}
@Override
public void mouseExited(MouseEvent e) {
str = "exited";
repaint();
}
}