Thread: need help, Problem in JScrollPane

Sir i have a problem with JScrollPane, it suppose to appear JScrollPane when they reach the limit size, but as you can see nothings happen, can someone help me with this one, that will be appreciated... thx

Output:

import javax.swing.*;
 
import java.awt.*;
 
public class test {
 
	static int colsPass = 10, rowsPass = 10;
	static int fHeight, fWidth;
	static int[] colsAlign = new int[3];
	static int[] rowsAlign = new int[3];
	static int set = 0;
	static int tCell = 0;
	static int loop1, loop2;
 
	public static void main(String[] args){
		scrollPane();
	}
 
	private static void scrollPane() {
 
		fWidth = ((colsPass*3)*20)+230;
		fHeight = (colsPass*20)+200;
		tCell = rowsPass * colsPass;
 
		JFrame frame = new JFrame("test scroll");
		frame.setSize(fWidth + 35, fHeight + 120);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		JPanel panel = new JPanel();
		panel.setLayout(null);
		panel.setLocation(fWidth, fHeight);
		frame.add(panel);
 
		JPanel panel2 = new JPanel();
		panel2.setLayout(null);
		panel2.setLocation(fWidth, fHeight);
		JScrollPane scroll = new JScrollPane(panel2);
		scroll.setBounds(10, 10, fWidth, fHeight);
		panel.add(scroll);
 
		JTextField[] txtArray1 = new JTextField[tCell];
		JTextField[] txtArray2 = new JTextField[tCell];
		JTextField[] txtArray3 = new JTextField[tCell];
 
		try {
			rowsAlign[0] = 60;
			rowsAlign[1] = 60;
			rowsAlign[2] = 60;
			for (loop1 = 0; loop1 <= rowsPass-1; loop1++){
				colsAlign[0] = 60;
				colsAlign[1] = (colsPass*25)+100;
				colsAlign[2] = ((colsPass*2)*25)+140;
 
				for (loop2 = 0; loop2 <= colsPass-1; loop2++){
					txtArray1[set] = new JTextField("");
					txtArray1[set].setBounds(colsAlign[0], rowsAlign[0], 20, 20);
					panel2.add(txtArray1[set]);
					colsAlign[0] += 25;
 
					txtArray2[set] = new JTextField("");
					txtArray2[set].setBounds(colsAlign[1], rowsAlign[1], 20, 20);
					panel2.add(txtArray2[set]);
					colsAlign[1] += 25;
 
					txtArray3[set] = new JTextField("");
					txtArray3[set].setBounds(colsAlign[2], rowsAlign[2], 20, 20);
					panel2.add(txtArray3[set]);
					colsAlign[2] += 25;
					set++;
 
				}
				loop2 = 0;
				rowsAlign[0] += 25;
				rowsAlign[1] += 25;
				rowsAlign[2] += 25;
			}
		}
		catch (Exception e) {}
		frame.setVisible(true);
	}
}

You set the layout of the JPanel within the JScrollPane to null which may be part of the problem. I'd recommend first setting up the panel with an appropriate layout (a combination of BoxLayouts with verticals and horizontals would work), all the while setting the preferred size (and maximums/minimums if necessary) of each component so it can let the JScrollPane know if it needs to scroll

how can i set up layout to JPanel, can you pls. give me some example. if you dont mind.

isn't ok to set an JScrollPane to JPanel and another JPanel within the JScrollPane ?

You can set up a JPanel within a JPanel, for example, the following code will set up two JPanels with dimensions 200x200 adjacent to each other using the BoxLayout which I alluded to above (see How to Use BoxLayout (The Java™ Tutorials > Creating a GUI With JFC/Swing > Laying Out Components Within a Container) )

Dimension dim = new Dimension(200,200);
JPanel panel1 = new JPanel();
panel1.setPreferredSize(dim);
JPanel panel2 = new JPanel();
panel2.setPreferredSize(dim);
JPanel holder = new JPanel();
holder.setLayout( new BoxLayout( holder, BoxLayout.LINE_AXIS ) );
holder.add(panel1);
holder.add(panel2);

All done, thx for your help, i hope there's a lot of people like you in this forum, thx.. very appreciated.....