grids.java

这个是Java的swing相关的典型的源码

/*
public class Canvasextends Component implements Accessible

A Canvas component represents a blank rectangular area of the screen onto which the application can draw or from which the application can trap input events from the user. 

An application must subclass the Canvas class in order to get useful functionality such as creating a custom component. The paint method must be overridden in order to perform custom graphics on the canvas. 
*/

import java.awt.Canvas;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

/**
 * Program to draw grids.
 * 
 * @author Ian Darwin, http://www.darwinsys.com/
 */
class GridsCanvas extends Canvas {
  int width, height;

  int rows;

  int cols;

  GridsCanvas(int w, int h, int r, int c) {
    setSize(width = w, height = h);
    rows = r;
    cols = c;
  }

  public void paint(Graphics g) {
    int i;
    width = getSize().width;
    height = getSize().height;

    // draw the rows
    int rowHt = height / (rows);
    for (i = 0; i < rows; i++)
      g.drawLine(0, i * rowHt, width, i * rowHt);

    // draw the columns
    int rowWid = width / (cols);
    for (i = 0; i < cols; i++)
      g.drawLine(i * rowWid, 0, i * rowWid, height);
  }
}

/** This is the demo class. */

public class Grids extends Frame {
  /*
   * Construct a GfxDemo2 given its title, width and height. Uses a
   * GridBagLayout to make the Canvas resize properly.
   */
  Grids(String title, int w, int h, int rows, int cols) {
    setTitle(title);

    // Now create a Canvas and add it to the Frame.
    GridsCanvas xyz = new GridsCanvas(w, h, rows, cols);
    add(xyz);

    addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        setVisible(false);
        dispose();
        System.exit(0);
      }
    });

    // Normal end ... pack it up!
    pack();
  }

  public static void main(String[] a) {
    new Grids("Test", 300, 300, 5, 10).setVisible(true);
  }
}