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DrawTools（画图工具）原始版本

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上一篇文章

一个优秀的C#开源绘图软件 DrawTools

中详细的介绍了DrawTools的几种演化的较高版本的软件的特色与功能。

这篇文章，将介绍一下这款软件的成名版本， 下载地址

DrawTool_Origin.rar

。


Introduction




DrawTools

sample shows how to create a Windows Forms application for drawing graphic objects in a Windows client area using mouse and drawing tools. Drawing tools implemented in this sample are: Rectangle, Ellipse, Line, and Pencil. There are well-known techniques for creating such type of applications, like: interaction with mouse, flicker-free drawing, implementing of drawing and selection tools, objects selection, managing of objects Z-order etc. MFC developers may learn all this stuff from MFC sample

DRAWCLI

. DrawTools C# program reproduces some of DRAWCLI functionality and uses some design decisions from this sample.


介绍



DrawTools


示例告诉你怎么创建一个

Windows

窗体，来使用鼠标和画图工具在窗体上的可用区域画图。这个示例中实现了以下画图工具：矩形，椭圆形，直线和铅笔。其中有一些众所周知的技术来创建这个

程序

，比如说：鼠标的交互，无闪烁画图，实现了画图和工具选择，物体选择，控制物体的

Z

轴次序，等等。

MFC

开发者可以从

DRAWCLI.

这个

MFC

示例中了解到所有这些特性。

DrawTools

这个

C#

程序复制了一些

DRAWCLI

的功能，并且在这个例子中使用了一些设计决定。


DrawTools solution contains two projects:

DrawTools

Windows Forms application and

DocToolkit

Class Library.

DrawTools

implements specific application stuff, and

DocToolkit

contains some standard classes for file managing.


Main features of the

DrawTools

solution are described below.


DrawTools

解决方案包括两个工程：


DrawTools


窗体应用程序和


DocToolkit


类库。


DrawTools


实现了一些特别的应用程序功能，


DocToolkit


包含有一些用于文件管理的标准类库。

以下描述了DrawTools 解决方案的主要特点：

  • DrawArea – user control which fills main application window client area. Contains instance of the GraphicsList class. Draws graphic objects, handles mouse input passing commands to GraphicsList.
  • GraphicsList – list of graphic objects. Contains ArrayList of graphic objects. Talks with each graphic object by generic way using DrawObject methods.
  • DrawObject – abstract base class for all graphic objects.
  • DrawRectangle – rectangle graphic object.
  • DrawEllipise – ellipse graphic object.
  • DrawLine – line graphic object.
  • DrawPolygon – polygon graphic object.
  • Tool – abstract base class for all drawing tools.
  • ToolPointer – pointer tool (neutral tool). Contains implementation for selection, moving, resizing of graphic objects.
  • ToolObject – abstract base class for all tools which create new graphic object.
  • ToolRectangle – rectangle tool.
  • ToolEllipse – ellipse tool.
  • ToolLine – line tool.
  • ToolPolygon – polygon tool.
  • DrawArea – 用来填充主程序在窗体上可用区域的用户控件。包括GraphicsList 类的实例。绘制图形对象, 处理鼠标输入，把（鼠标）命令传给GraphicsList。
  • GraphicsList – 图形对象的列表。包括图形对象的ArrayList。通过使用DrawObject类中的方法与其他图形对象通讯
  • DrawObject – 所有图形对象的抽象基类。
  • DrawRectangle – 矩形图形对象。
  • DrawEllipise – 椭圆形图形对象。
  • DrawLine – 直线图形对象。
  • DrawPolygon – 多边形图形对象。
  • Tool – 所有画图工具的抽象基类。
  • ToolPointer – 箭头工具 (中性工具)。包含选择，移动，改变图形对象大小的实现。
  • ToolObject – 所有工具的抽象基类，用来创建新的图形对象。ToolRectangle – 矩形工具。
  • ToolEllipse – 椭圆形工具。
  • ToolLine – 直线工具。
  • ToolPolygon – 多边形工具。


DocToolkit Library




DocToolkit

Library contains set of classes which may be used for creation of document-centric Windows Forms applications. Instances of classes exported from the DocToolkit Library are kept in the main form of the

DrawTools

project and used for general file-related operations.




DocToolkit

类库



DocToolkit

类库包含一些类的集合，这些类用来创建文档中心（

document-centric

）的窗体应用程序。从

DocToolkit

类库输出的类的实例被保存在

DrawTools

工程的主窗口中，用作一般的文件操作。

  • DocManager class: Makes file-related operations: open, new, save, updating of the form title, registering of file type for Windows Shell. Built using the article

    Creating Document-Centric Applications in Windows Forms

    by

    Chris Sells

    .
  • DragDropManager class: Allows to open files dropped from Windows Explorer in Windows Form application.
  • MruManager class: Manages Most Recently Used Files list.
  • PersistWindowState class: Allows to keep last window state in the Registry and restore it when form is loaded. Source:

    Saving and Restoring the Location, Size and Windows State of a .NET Form

    By

    Joel Matthias

    .
  • DocManager 类: 处理文件操作:打开，新建，保存，更新窗体标题，为Windows Shell注册文件类型。创建这个类引用了

    Chris Sells

    的

    文章


    Creating Document-Centric Applications in Windows Forms

    。
  • DragDropManager 类: 在Windows Form应用程序中允许你通过拖拽的方式从浏览器(文件浏览器)中打开文件。
  • MruManager 类: 管理大多数最近使用的文件列表。
  • PersistWindowState 类: 允许你把最近一次的窗口状态保存到注册表 ，在窗体载入的时候重新获得。来源:

    Saving and Restoring the Location, Size and Windows State of a .NET Form

    By

    Joel Matthias

    .


Handling of Windows controls state at application idle time


Every Windows Forms application has a number of controls like menu items, buttons, toolbar buttons etc. Depending on current situation and user commands, these controls may have different states: enabled/disabled, checked/unchecked, visible/invisible etc. Every user action may change this state. Setting of controls’ state in every message handler may be error-prone. Instead of this, it is better to manage controls’ state in some function which is called after every user action. MFC has the great



ON_UPDATE_COMMAND_UI



feature which allows to update toolbar buttons’ state at application idle time. Such a feature may be implemented also in .NET programs.


在程序空闲的时候操作


Windows


的控件状态

每一个Windows窗体应用程序都会有许多控件，比如说菜单项，按钮，工具栏按钮等等。根据当前状态和用户的命令，这些控件可能有不同的状态：

enabled/disabled

，

checked/unchecked, visible/invisible

等等。用户的每一个操作可能改变这些状态。在每一个消息句柄中改变控件的状态可能导致错误。取而代之的方法是，在用户每一个操作后调用一些函数，在这些函数中管理控件的状态。

MFC

有一个很好的特性叫


ON_UPDATE_COMMAND_UI


，


它允许在应用程序的空闲时间更新工具栏按钮的状态。这个特性也可以在.NET程序中实现。

Consider the situation when user clicks the Rectangle toolbar button. This button should be checked, and previously active tool should be unchecked. Rectangle button message handler doesn’t change form controls’ state, it just keeps current selection in some variable. Idle message handler selects active tool and unselects inactive tool.

考虑一下这种情形：当用户点击工具栏上的Rectangle按钮，这个按钮就要显示为被选中，前一个激活的工具就要显示为没选中。Rectangle按钮的消息句柄并没有改变窗体控件的状态，它只是在一些变量中保存了当前的选择。空闲的消息句柄选择激活的工具，取消未激活工具的选择。

private void Form1_Load(object sender, System.EventArgs e)

{

// Submit to Idle event to set controls state at idle time

Application.Idle += new EventHandler(Application_Idle);

}

private void Application_Idle(object sender, EventArgs e)

{

SetStateOfControls();

}

public void SetStateOfControls()

{

// Select active tool

tbPointer.Pushed = (drawArea.ActiveTool == DrawArea.DrawToolType.Pointer);

tbRectangle.Pushed = (drawArea.ActiveTool == DrawArea.DrawToolType.Rectangle);

tbEllipse.Pushed  = (drawArea.ActiveTool == DrawArea.DrawToolType.Ellipse);

tbLine.Pushed = (drawArea.ActiveTool == DrawArea.DrawToolType.Line);

tbPolygon.Pushed = (drawArea.ActiveTool == DrawArea.DrawToolType.Polygon);

menuDrawPointer.Checked =

(drawArea.ActiveTool == DrawArea.DrawToolType.Pointer);

menuDrawRectangle.Checked =

(drawArea.ActiveTool == DrawArea.DrawToolType.Rectangle);

menuDrawEllipse.Checked =

(drawArea.ActiveTool == DrawArea.DrawToolType.Ellipse);

menuDrawLine.Checked = (drawArea.ActiveTool == DrawArea.DrawToolType.Line);

menuDrawPolygon.Checked =

(drawArea.ActiveTool == DrawArea.DrawToolType.Polygon);

//

}

// Rectangle tool is selected

private void CommandRectangle()

{

drawArea.ActiveTool = DrawArea.DrawToolType.Rectangle;

}


Hit Test



DrawObject



class has virtual



HitTest



function which detects whether point belongs to graphic object:


Hit Test



DrawObject


类有一个叫


HitTest


的虚拟函数，用来侦测是否Point属于图形对象。

public virtual int HitTest(Point point)

{

return -1;

}


Derived classes use virtual



PointInObject



to make hit test. This function is called from



HitTest



.



DrawRectangle



class implements this function by a simple way:

继承类使用虚拟的


PointInObject


来做点击测试。这个函数调用自


HitTest


。


DrawRectangle


类使用了一种简单的方法实现了这个函数：

protected override bool PointInObject(Point point)

{

return rectangle.Contains(point);

// rectangle is class member of type Rectangle

}



DrawLine



implementation of this function is more complicated:



DrawLine


对这个函数的实现更加复杂：

protected override bool PointInObject(Point point)

{

GraphicsPath areaPath;

Pen areaPen;

Region areaRegion;

// Create path which contains wide line

// for easy mouse selection

AreaPath = new GraphicsPath();

AreaPen = new Pen(Color.Black, 7);

AreaPath.AddLine(startPoint.X, startPoint.Y, endPoint.X, endPoint.Y);

// startPoint and EndPoint are class members of type Point

AreaPath.Widen(AreaPen);

// Create region from the path

AreaRegion = new Region(AreaPath);

return AreaRegion.IsVisible(point);

}



DrawPolygon



function works by the same way, but



AreaPath



contains all lines in the polygon.



DrawPolygon


函数使用了同样的方法，但是


AreaPath


包含了多边形的所有线。


Serialization



GraphicList



class implements



ISerializable



interface which allows to make binary serialization of the class object.



DrawObject



class has two virtual functions which are used for serialization:


序列化



GraphicList


类实现了


ISerializable


接口，这个接口用作类对象的二进制序列化。


DrawObject


类有两个虚函数用来做序列化。

public virtual void SaveToStream(SerializationInfo info, int orderNumber)

{


//

}

public virtual void LoadFromStream(SerializationInfo info, int orderNumber)