/// <summary>
/// defines Command interface
/// Command Patterns命令模式
/// 20220918
/// geovindu,Geovin Du,塗聚文
/// </summary>
public interface Command
{
/// <summary>
///
/// </summary>
void Execute();
/// <summary>
///
/// </summary>
void Undo();
/// <summary>
///
/// </summary>
/// <returns></returns>
bool isUndo();
}
/// <summary>
/// Summary description for ColorCommand.
/// Command Patterns命令模式
/// 20220918
/// geovindu,Geovin Du,塗聚文
/// </summary>
public class ColorCommand : Command
{
protected Color color; //line color
protected PictureBox pbox; //box to draw in
protected ArrayList drawList; //list of lines
protected int x, y, dx, dy; //coordinates
/// <summary>
///
/// </summary>
/// <param name="pict"></param>
public ColorCommand(PictureBox pict)
{
pbox = pict; //copy in picture box
drawList = new ArrayList(); //create list
}
/// <summary>
///
/// </summary>
public void Execute()
{
//create a new line to draw
DrawData dl = new DrawData(x, y, dx, dy);
drawList.Add(dl); //add it to the list
x = x + dx; //increment the positions
y = y + dy;
pbox.Refresh();
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public bool isUndo()
{
return false;
}
/// <summary>
///
/// </summary>
public void Undo()
{
DrawData dl;
int index = drawList.Count - 1;
if (index >= 0)
{
dl = (DrawData)drawList[index];
drawList.RemoveAt(index);
x = dl.getX();
y = dl.getY();
}
pbox.Refresh();
}
/// <summary>
///
/// </summary>
/// <param name="g"></param>
public void draw(Graphics g)
{
Pen rpen = new Pen(color, 1);
int h = pbox.Height;
int w = pbox.Width;
//draw all the lines in the list
for (int i = 0; i < drawList.Count; i++)
{
DrawData dl = (DrawData)drawList[i];
g.DrawLine(rpen, dl.getX(), dl.getY(), dl.getX() + dx, dl.getDy() + h);
}
}
}
/// <summary>
/// Summary description for DrawData.
/// Command Patterns命令模式
/// 20220918
/// geovindu,Geovin Du,塗聚文
/// </summary>
public class DrawData
{
/// <summary>
///
/// </summary>
private int x, y, dx, dy;
/// <summary>
///
/// </summary>
/// <param name="x_"></param>
/// <param name="y_"></param>
/// <param name="dx_"></param>
/// <param name="dy_"></param>
public DrawData(int x_, int y_, int dx_, int dy_)
{
x = x_;
dx = dx_;
y = y_;
dy = dy_;
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public int getX()
{
return x;
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public int getY()
{
return y;
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public int getDx()
{
return dx;
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public int getDy()
{
return dy;
}
}
/// <summary>
/// Summary description for RedCommand.
/// Command Patterns命令模式
/// 20220918
/// geovindu,Geovin Du,塗聚文
/// </summary>
public class RedCommand : ColorCommand
{
/// <summary>
///
/// </summary>
/// <param name="pict"></param>
public RedCommand(PictureBox pict)
: base(pict)
{
color = Color.Red;
x = 0;
dx = 20;
y = 0;
dy = 0;
}
}
/// <summary>
/// Summary description for UndoCommand.
/// Command Patterns命令模式
/// 20220918
/// geovindu,Geovin Du,塗聚文
/// </summary>
public class UndoComd : Command
{
/// <summary>
///
/// </summary>
private ArrayList undoList;
/// <summary>
///
/// </summary>
public UndoComd()
{
undoList = new ArrayList();
}
/// <summary>
///
/// </summary>
/// <param name="comd"></param>
public void add(Command comd)
{
if (!comd.isUndo())
{
undoList.Add(comd);
}
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public bool isUndo()
{
return true;
}
/// <summary>
///
/// </summary>
public void Undo() { }
/// <summary>
///
/// </summary>
public void Execute()
{
int index = undoList.Count - 1;
if (index >= 0)
{
Command cmd = (Command)undoList[index];
cmd.Undo();
undoList.RemoveAt(index);
}
}
}
/// <summary>
/// Summary description for CommandHolder.
/// Command Patterns命令模式
/// 20220918
/// geovindu,Geovin Du,塗聚文
/// </summary>
public interface CommandHolder
{
/// <summary>
///
/// </summary>
/// <returns></returns>
Command getCommand();
/// <summary>
///
/// </summary>
/// <param name="cmd"></param>
void setCommand(Command cmd);
}
/// <summary>
/// draws bluelines and caches list for undo
/// Command Patterns命令模式
/// 20220918
/// geovindu,Geovin Du,塗聚文
/// </summary>
public class BlueCommand : ColorCommand
{
/// <summary>
///
/// </summary>
/// <param name="pict"></param>
public BlueCommand(PictureBox pict)
: base(pict)
{
color = Color.Blue;
x = pbox.Width;
dx = -20;
y = 0;
dy = 0;
}
}
/// <summary>
/// Command Patterns命令模式
/// 20220918
/// geovindu,Geovin Du,塗聚文
/// </summary>
public partial class CommandButton : Button, CommandHolder
{
private Command command;
/// <summary>
///
/// </summary>
/// <param name="comd"></param>
public void setCommand(Command comd)
{
command = comd;
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public Command getCommand()
{
return command;
}
public CommandButton()
{
InitializeComponent();
}
public CommandButton(IContainer container)
{
container.Add(this);
InitializeComponent();
}
}
調用試試：
/// <summary>
/// Command Patterns
/// Command Patterns命令模式
/// 20220918
/// geovindu,Geovin Du,塗聚文
/// </summary>
public partial class CommandPatternsForm : Form
{
private BlueCommand blueC;
private RedCommand redC;
private UndoComd undoC;
/// <summary>
///
/// </summary>
public CommandPatternsForm()
{
InitializeComponent();
init();
}
/// <summary>
///
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void CommandPatternsForm_Load(object sender, EventArgs e)
{
}
/// <summary>
///
/// </summary>
private void init()
{
btBlue.setCommand(blueC = new BlueCommand(pBox));
btRed.setCommand(redC = new RedCommand(pBox));
btUndo.setCommand(undoC = new UndoComd());
EventHandler evh = new EventHandler(commandClick);
btBlue.Click += evh;
btRed.Click += evh;
btUndo.Click += evh;
pBox.Paint += new PaintEventHandler(paintHandler);
}
/// <summary>
///
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void commandClick(object sender, EventArgs e)
{
//get the command
Command comd = ((CommandHolder)sender).getCommand();
undoC.add(comd); //add to undo list
comd.Execute(); //and execute it
}
/// <summary>
///
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
public void paintHandler(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
blueC.draw(g);
redC.draw(g);
}
}
輸出：
