橡皮区矩形 CRectTracker C# 实现


作者：fanjunxing

下载源代码


本文要求读者熟悉 C#

开发环境： Visual Studio .NET 2003 Windows 2000

测试环境：Windows 2000

更新记录：2004.4.7 第一次更新

使用许可：代码是否免费使用

功能介绍：
　　在MFC中CRectTracker是一个很有用的类，可最近学习C#时，发现没有，于是就从MFC转换了一个供大家享用。



使用该类比较简单，几乎和 MFC中 的 CRectTracker 一样，在MDI中：

public class CReportDoc 
{	...
public CRectTracker m_tracker=null; 

	public CReportDoc(MainWindow mainWin) 
	{	 ...
		m_tracker=new CRectTracker(); 
		m_tracker.m_rect.X = 10; 
		m_tracker.m_rect.Y = 10;
		m_tracker.m_rect.Width = 91;
		m_tracker.m_rect.Height = 91; 
		...
	}
	...
}      

public class CReportView : System.Windows.Forms.Form 
{
     ...
     private void InitializeComponent() 
     { 
	...
	this.MouseDown += 
	new System.Windows.Forms.MouseEventHandler(this.CReportView_MouseDown); 
	this.Paint += 
	new System.Windows.Forms.PaintEventHandler(this.PaintHandler); 

	// 因为C#中不支持OnSetCursor所以只好用MouseMove替代了，
	// 各位兄台还有更好的方法，请告之
	this.MouseMove+=new MouseEventHandler(CReportView_MouseMove); 
     }

     private void PaintHandler(Object sender, PaintEventArgs e) 
     {
	Graphics gs=e.Graphics; 

	//其余的画图代码
	myDoc.m_tracker.OnDraw(gs); 
     }
     private void CReportView_MouseDown(object sender, 
                                   MouseEventArgs e) 
     {
     if(e.Button==MouseButtons .Left) 
     {
	Rectangle rectSave=new Rectangle(); 
	Point pt=new Point(e.X,e.Y);
	myDoc.m_tracker.GetTrueRect(ref rectSave);
	if (myDoc.m_tracker.HitTest(pt) < 0) 
	{ // just to demonstrate CRectTracker::TrackRubberBand 
		CRectTracker tracker=new CRectTracker();
		if (tracker.TrackRubberBand(this, 
		                            pt, 
					myDoc.m_bAllowInvert))
		{   // see if rubber band intersects with the doc''s tracker 
			tracker.NormalizeRect(ref tracker.m_rect);
			// so intersect rect works
			if (tracker.m_rect.IntersectsWith(myDoc.m_tracker.m_rect))
			{  // if so, put resize handles on it (ie. select it) 
				if ((myDoc.m_tracker.m_nStyle &
					 CRectTracker.StyleFlags.resizeInside)!=0) 
				{   // swap from resize inside to 
					// resize outside for effect
					myDoc.m_tracker.m_nStyle &= 
					~CRectTracker.StyleFlags.resizeInside; 
					myDoc.m_tracker.m_nStyle |= 
					CRectTracker.StyleFlags.resizeOutside;
				} 
				else 
				{// just use inside resize handles on first time 
					myDoc.m_tracker.m_nStyle &= 
					 ~CRectTracker.StyleFlags.resizeOutside; 
					myDoc.m_tracker.m_nStyle |= 
						 CRectTracker.StyleFlags.resizeInside; 
				} 
			}
		}
		myDoc.UpdateAllViews(null); 
	     } 
	} 
	else 
	{
	    if (myDoc.m_tracker.Track(this, 
		 pt, 
	          myDoc.m_bAllowInvert,null)) 
	    {   
		// normal tracking action, when tracker is "hit"
		myDoc.UpdateAllViews(null);
	    }
	}
     }

     private void CReportView_MouseMove(object sender, MouseEventArgs e)
     {
	Point mousept=new Point(e.X,e.Y); 
	if(!myDoc.m_tracker.SetCursor(this,0,mousept)) 
	this.Cursor=Cursors.Arrow;
     }
     ...
}