您可以使用布局管理器来布局JPanel
,并在其上方进行自定义绘制。
这不会阻止您使用pack()
1 。
以下mre 2 演示了如何使用JPanel
在GridLayout
上画一条线:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.util.ArrayList;
import java.util.List;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class NetworkViewPanel extends JPanel{
private final List<JLabel> labels;
public NetworkViewPanel() {
this.setLayout(new GridLayout(2,2,2));
this.setPreferredSize(new Dimension(400,300));//used by pack()
labels = new ArrayList<>();
addLabels(new String[]{ "A","B","C","D"});
}
private void addLabels(String[] text){
for(String t: text){
JLabel label = new JLabel(t);
label.setBorder(BorderFactory.createLineBorder(Color.BLUE));
label.setHorizontalAlignment(JLabel.CENTER);
add(label);
labels.add(label);
}
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g); //draw panel as layed out by layout manager
drawLines(g);
}
private void drawLines(Graphics g) {
//draw line between centers of first and last components
int x1 = labels.get(0).getBounds().x + labels.get(0).getBounds().width /2;
int y1 = labels.get(0).getBounds().y + labels.get(0).getBounds().height /2;
int x2 = labels.get(labels.size()-1).getBounds().x + labels.get(labels.size()-1).getBounds().width/2;
int y2 = labels.get(labels.size()-1).getBounds().y + labels.get(labels.size()-1).getBounds().height/2;
g.setColor(Color.RED);
g.drawLine(x1,y1,x2,y2);
}
public static void main(String[] args) {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setLocationRelativeTo(null);
f.add(new NetworkViewPanel());
f.pack();
f.setVisible(true);
}
}
1 参见:
What does .pack() do? 2 在询问或回答
时考虑发布信息
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