中利用設計繪圖程序初步呢

首先我們說下通過鼠標的移動來繪制直線。

這里要捕獲到鼠標的兩個消息：WM_LBUTTONDOWN, WM_LBUTTONUP。響應WM_LBUTTONDOWN消息記錄直線的起始點，響應WM_LBUTTONUP消息記錄直線的終點并繪制直線。

好了，我們看看怎么響應。

void CDrawView::OnLButtonDown(UINT nFlags, CPoint point)

{

//MessageBox(\"Left Button Clicks DrawView\");

m_ptOrigin = point ; //這里先定義了一個內部變量保存直線的起始點

CView::OnLButtonDown(nFlags, point);

}

下面看看響應WM_LBUTTONUP消息記錄直線的終點并繪制直線。

//方法一

void CDrawView::OnLButtonUp(UINT nFlags, CPoint point)

{

HDC hdc;

hdc = ::GetDC(m_hWnd); //調用全局函數

MoveToEx(hdc,m_ptOrigin.x,m_ptOrigin.y,0);

LineTo(hdc,point.x,point.y);

::ReleaseDC(m_hWnd,hdc);

CView::OnLButtonUp(nFlags, point);

}

//方法二

void CDrawView::OnLButtonUp(UINT nFlags, CPoint point)

{

CDC *pDC = GetDC();

pDC-MoveTo(m_ptOrigin);

pDC-LineTo(point);

ReleaseDC(pDC);

}

//方法三

void CDrawView::OnLButtonUp(UINT nFlags, CPoint point)

{

CClientDC dc(this) ; //CClientDC對象構造的時候就調用了GetDC，析構的時候調用

ReleaseDC ，只能訪問客戶區

CClientDC dc(GetParent());

veTo(m_ptOrigin);

neTo(point);

}

//方法四

void CDrawView::OnLButtonUp(UINT nFlags, CPoint point)

{

CWindowDC dc(this) ; //CWindowDC可以訪問客戶區和非客戶區

veTo(m_ptOrigin);

neTo(point);

}

void CDrawView::OnLButtonUp(UINT nFlags, CPoint point)

{

CWindowDC dc(GetDesktopWindow()) ; //現在可以訪問桌面

veTo(m_ptOrigin);

neTo(point);

}

連續線繪圖：

思路：鼠標移動的信號被捕捉到，然后隨時響應該信號，繪制圖線。

這里要設置一個BOOL變量 m_bDraw 來判斷是否鼠標左鍵按下了。

//畫連續的線條

void CDrawView::OnMouseMove(UINT nFlags, CPoint point)

{

if ( m_bDraw )

{

CClientDC dc(this) ;

veTo(m_ptOrigin); //移動到原來的點

neTo(point); //繪制直線

m_ptOrigin = point ; //將現在的點賦值給原來的坐標，以便下次調用

}

CView::OnMouseMove(nFlags, point);

}

//改變畫筆的顏色

void CDrawView::OnMouseMove(UINT nFlags, CPoint point)

{

if ( m_bDraw )

{

CClientDC dc(this) ;

CPen pen( PS_SOLID , 1 , RGB(255,128,128) );

CPen *pOldPen = lectObject(pen);

veTo(m_ptOrigin);

neTo(point);

m_ptOrigin = point ;

lectObject(pOldPen);

}

CView::OnMouseMove(nFlags, point);

}

//畫扇型

void CDrawView::OnMouseMove(UINT nFlags, CPoint point)

{

if ( m_bDraw )

{

CClientDC dc(this) ;

CPen pen( PS_SOLID , 1 , RGB(255,128,128) );

CPen *pOldPen = lectObject(pen);

但由于F-86過于笨重 veTo(m_ptOrigin);

neTo(m_ptOld);

veTo(m_ptOrigin);

neTo(point);

m_ptOld = point ;

lectObject(pOldPen);

}

CView::OnMouseMove(nFlags, point);

}

//畫帶邊線的扇型

void CDrawView::OnMouseMove(UINT nFlags, CPoint point)

{

if ( m_bDraw )

{

CClientDC dc(this) ;

CPen pen( PS_SOLID , 1 , RGB(255,128,128) );

CPen *pOldPen = lectObject(pen);

veTo(m_ptOrigin);

neTo(m_ptOld);

veTo(m_ptOrigin);

neTo(point);

veTo(m_ptOld);

neTo(point);

m_ptOld = point ;

lectObject(pOldPen);

}

CView::OnMouseMove(nFlags, point);

}

//看看繪圖的模式設置方法

void CDrawView::OnMouseMove(UINT nFlags, CPoint point)

{

if ( m_bDraw )

{

CClientDC dc(this) ;

tROP2(R2_BLACK); //繪圖的模式設置,始終繪制黑色圖形

CPen pen( PS_SOLID , 1 , RGB(255,128,128) );

CPen *pOldPen = lectObject(pen);

veTo(m_ptOrigin);

neTo(m_ptOld);

veTo(m_ptOrigin);

neTo(point);

veTo(m_ptOld);

neTo(point);

m_ptOld = point ;

lectObject(pOldPen);

}

CView::OnMouseMove(nFlags, point);

}

到此，我們知道了一般地繪圖方法了。查看本文來源