1、繪製矩形
創建一個繪製矩形的函數，本次是用繪製多邊形的函數定義的，定義繪製四條變的矩形區域。
先進行函數聲明：
void DrawRectangle1(Gdiplus::Point rectangle_points[], CPoint oript, CPoint detpt)
然後定義函數（selected_rect_是之前定義了一個矩形框，使畫的東西在框的區域內）：
void CdrawtestDlg::DrawRectangle1Gdiplus(Gdiplus::Point rectangle_points[], CPoint oript, CPoint detpt){ if (!(oript.x >= selected_rect_.left && oript.x <= selected_rect_.right && oript.y > selected_rect_.top && oript.y < selected_rect_.bottom)) { return; } if (!(detpt.x >= selected_rect_.left && detpt.x <= selected_rect_.right && detpt.y > selected_rect_.top && detpt.y < selected_rect_.bottom)) { return; } if (drawing_mode_ == deawingrectangle) { rectangle_points[0] = Gdiplus::Point(oript.x, oript.y); rectangle_points[1] = Gdiplus::Point(detpt.x, oript.y); rectangle_points[2] = Gdiplus::Point(detpt.x, detpt.y); rectangle_points[3] = Gdiplus::Point(oript.x, detpt.y); InvalidateRect(selected_rect_, false); } }
定義變量：
/*矩形定義*/ BOOL is_selected;//是否選中 BOOL is_select;//是否選中 BOOL is_scale;//是否縮放 BOOL is_move;//是否移動
並初始化爲FALSE，在對話框點擊繪製按鈕那響應爲TURE。
在ONPaint函數中添加以下代碼：
if (drawing_mode_==deawingrectangle||is_move||is_scale)
{
g.DrawPolygon(&pen3,rectangle_point_,4);
}
添加消息響應函數鼠標左鍵按下的響應，並添加以下代碼：
if (draw_mode_ == rectangle) { drawing_mode_ = deawingrectangle; rectangle_point_[0].X = point.x; rectangle_point_[0].Y = point.y; rectangle_point_[1].X = point.x; rectangle_point_[1].Y = point.y; rectangle_point_[2].X = point.x; rectangle_point_[2].Y = point.y; rectangle_point_[3].X = point.x; rectangle_point_[3].Y = point.y; }
添加鼠標移動的響應函數並編輯：
if (drawing_mode_ == deawingrectangle) { SetCursor(h_cur_); DrawRectangle1Gdiplus(rectangle_point_, CPoint(rectangle_point_[0].X, rectangle_point_[0].Y), point); }
添加鼠標擡起響應函數：
if (drawing_mode_ == deawingrectangle) { Gdiplus::GraphicsPath gpath_rectangle; temp_path.AddPolygon(rectangle_point_, 4); temp_path.AddPath(&gpath_rectangle, FALSE); gpath_rectangle.Reset(); InvalidateRect(selected_rect_, false); drawing_mode_ = invalid; }
這樣就可以畫矩形了，效果如下：
2、添加旋轉、縮放並且移動
主要是要跟隨鼠標移動進行旋轉
首先我們要繪製標誌點，當選中標誌點的時候矩形旋轉
所以在鼠標左鍵按下的響應函數添加以下代碼：
void CdrawtestDlg::OnLButtonDown(UINT nFlags, CPoint point) { // TODO: 在此添加消息處理程序代碼和/或調用默認值 if (is_draw) { if (draw_mode_==arrow) { drawing_mode_=drawingarrow; arrow_points_[0].X = point.x; arrow_points_[0].Y = point.y; arrow_points_[1].X = point.x; arrow_points_[1].Y = point.y; arrow_points_[2].X = point.x; arrow_points_[2].Y = point.y; arrow_points_[3].X = point.x; arrow_points_[3].Y = point.y; arrow_points_[4].X = point.x; arrow_points_[4].Y = point.y; arrow_points_[5].X = point.x; arrow_points_[5].Y = point.y; } if (draw_mode_ == line) { start_pt_ = point; drawing_mode_ = drawingline; } if (draw_mode_ == rectangle) { drawing_mode_ = deawingrectangle; rectangle_point_[0].X = point.x; rectangle_point_[0].Y = point.y; rectangle_point_[1].X = point.x; rectangle_point_[1].Y = point.y; rectangle_point_[2].X = point.x; rectangle_point_[2].Y = point.y; rectangle_point_[3].X = point.x; rectangle_point_[3].Y = point.y; } if (draw_mode_ == ellipse) { drawing_mode_ = drawingellipse; start_pt_ = old_pt_ = point; } } if (is_selected) { Graphics graphics(this->m_hWnd); //構造環境變量指針 Point testPoint(point.x,point.y);//鼠標座標 Point TestPoint((rectangle_point_[0].X+rectangle_point_[1].X)/2-3,(rectangle_point_[0].Y+rectangle_point_[1].Y)/2-53);//選擇座標 SolidBrush solidBrush(Color(0,0,0,0)); SolidBrush brush1(Color(0,0,0)); Pen pen(Color(255,0,0,0)); GraphicsPath path; //定義路徑 /***********************此部分爲選中爲矩形區域***************************************************************************/ //構造矩形區域 path.AddClosedCurve(rectangle_point_,4); //鏈接區域 Region pathRegion(&path); //區域指向路徑 graphics.FillRegion(&solidBrush,&pathRegion); //填充區域 if (pathRegion.IsVisible(testPoint,&graphics))//如果在選擇區域是矩形 { INT count=path.GetPointCount(); Point* dataPoints=new Point[count]; for (INT j=0;j<count;j++) { graphics.FillEllipse( &brush1, dataPoints[j].X-3.0f, dataPoints[j].Y-3.0f, 6.0f, 6.0f ); //選中標誌 graphics.FillEllipse(&brush1,rectangle_point_[0].X-10,rectangle_point_[0].Y-10,6,6); graphics.FillEllipse(&brush1,rectangle_point_[1].X+10,rectangle_point_[1].Y-10,6,6); graphics.FillEllipse(&brush1,rectangle_point_[2].X+10,rectangle_point_[2].Y+10,6,6); graphics.FillEllipse(&brush1,rectangle_point_[3].X-10,rectangle_point_[3].Y+10,6,6); } //畫選中的把把 PointF point1((rectangle_point_[0].X+rectangle_point_[1].X)/2,(rectangle_point_[0].Y+rectangle_point_[1].Y)/2); PointF point2((rectangle_point_[0].X+rectangle_point_[1].X)/2,(rectangle_point_[0].Y+rectangle_point_[1].Y)/2-50); PointF points[2]={point1,point2}; PointF* pPoints=points; graphics.DrawLine(&pen,point1.X,point1.Y,point2.X,point2.Y); graphics.FillEllipse(&brush1,(rectangle_point_[0].X+rectangle_point_[1].X)/2-3,(rectangle_point_[0].Y+rectangle_point_[1].Y)/2-53,6,6); //畫選中的中心點 StartPoint.X = rectangle_point_[0].X; StartPoint.Y = rectangle_point_[0].Y; EndPoint.X = point.x; EndPoint.Y = point.y; C.X=(rectangle_point_[0].X+rectangle_point_[1].X)/2; C.Y=(rectangle_point_[0].Y+rectangle_point_[3].Y)/2; graphics.DrawLine(&pen,C.X,C.Y-3,C.X,C.Y+3); graphics.DrawLine(&pen,C.X-3,C.Y,C.X+3,C.Y); //初始化縮放座標點 rectangle_Spoint_[0].X=rectangle_point_[0].X; rectangle_Spoint_[0].Y=rectangle_point_[0].Y; rectangle_Spoint_[1].X=rectangle_point_[1].X; rectangle_Spoint_[1].Y=rectangle_point_[1].Y; rectangle_Spoint_[2].X=rectangle_point_[2].X; rectangle_Spoint_[2].Y=rectangle_point_[2].Y; rectangle_Spoint_[3].X=rectangle_point_[3].X; rectangle_Spoint_[3].Y=rectangle_point_[3].Y; //選中中心點 if (C.X-5<point.x && point.x<C.X+5) { if (C.Y-5< point.y && point.y<C.Y+5) { graphics.FillEllipse(&brush1,C.X-5,C.Y-5,10,10); is_move = TRUE; } } is_scale=TRUE;//只要在選中去內左鍵點過，就可以實現縮放功能 } //testPoint爲鼠標座標，TestPoint爲測試座標，是否選中(粑粑)標誌點 else if(((rectangle_point_[0].X+rectangle_point_[1].X)/2-13) < point.x && point.x<((rectangle_point_[0].X+rectangle_point_[1].X)/2+7)){ if (((rectangle_point_[0].Y+rectangle_point_[1].Y)/2-63)< point.y && point.y<((rectangle_point_[0].Y+rectangle_point_[1].Y)/2-43)) { graphics.FillEllipse(&brush1,(rectangle_point_[0].X+rectangle_point_[1].X)/2-7,(rectangle_point_[0].Y+rectangle_point_[1].Y)/2-55,15,15); is_select=TRUE; }} else return; } CDialogEx::OnLButtonDown(nFlags, point); }
在鼠標移動添加以下代碼：
void CdrawtestDlg::OnMouseMove(UINT nFlags, CPoint point) { // TODO: 在此添加消息處理程序代碼和/或調用默認值 GraphicsPath temp_path; if (is_draw) { if (drawing_mode_ == drawingline) { SetCursor(h_cur_); DrawLine(start_pt_, point); start_pt_ = point; } if (drawing_mode_ == drawingarrow) { SetCursor(h_cur_); DrawArrow(arrow_points_, CPoint(arrow_points_[0].X, arrow_points_[0].Y), point); } if (drawing_mode_ == deawingrectangle) { SetCursor(h_cur_); DrawRectangle1Gdiplus(rectangle_point_, CPoint(rectangle_point_[0].X, rectangle_point_[0].Y), point); } if (drawing_mode_ == drawingellipse) { SetCursor(h_cur_); old_pt_ = point; DrawEclipse(start_pt_, point); } } if (is_selected) { if (is_select) { Graphics graphics(this->m_hWnd); Pen pen(Color(255,0,0,0)); SetCursor(h_move_); DrawRectangle1Gdiplus(rectangle_point_, CPoint(rectangle_point_[0].X, rectangle_point_[0].Y), point); StartPoint.X = rectangle_point_[0].X; StartPoint.Y = rectangle_point_[0].Y; EndPoint.X = point.x; EndPoint.Y = point.y; C.X=(rectangle_point_[0].X+rectangle_point_[1].X)/2; C.Y=(rectangle_point_[0].Y+rectangle_point_[3].Y)/2; float theta =atan2f(EndPoint.X-C.X,EndPoint.Y-C.Y); double R,B; R=sqrt((double)(C.Y-rectangle_point_[0].Y)*(C.Y-rectangle_point_[0].Y)+(double)(C.X-rectangle_point_[0].X)*(C.X-rectangle_point_[0].X)); B=sin(theta/2)*2*R; //繪製中間選中標誌點 graphics.DrawLine(&pen,C.X,C.Y-3,C.X,C.Y+3); graphics.DrawLine(&pen,C.X-3,C.Y,C.X+3,C.Y); ////旋轉變換成菱形了~~~T-T~~~~ rectangle_points_[0].X=(rectangle_point_[0].X-C.X)*cos(theta)-(rectangle_point_[0].Y-C.Y)*sin(theta)+C.X; rectangle_points_[0].Y=(rectangle_point_[0].X-C.X)*sin(theta)-(rectangle_point_[0].Y-C.Y)*cos(theta)+C.Y; rectangle_points_[1].X=(rectangle_point_[1].X-C.X)*cos(theta)-(rectangle_point_[1].Y-C.Y)*sin(theta)+C.X; rectangle_points_[1].Y=(rectangle_point_[1].X-C.X)*sin(theta)-(rectangle_point_[1].Y-C.Y)*cos(theta)+C.Y; rectangle_points_[2].X=(rectangle_point_[2].X-C.X)*cos(theta)-(rectangle_point_[2].Y-C.Y)*sin(theta)+C.X; rectangle_points_[2].Y=(rectangle_point_[2].X-C.X)*sin(theta)-(rectangle_point_[2].Y-C.Y)*cos(theta)+C.Y; rectangle_points_[3].X=(rectangle_point_[3].X-C.X)*cos(theta)-(rectangle_point_[3].Y-C.Y)*sin(theta)+C.X; rectangle_points_[3].Y=(rectangle_point_[3].X-C.X)*sin(theta)-(rectangle_point_[3].Y-C.Y)*cos(theta)+C.Y; graphics.DrawLine(&pen,rectangle_points_[0].X,rectangle_points_[0].Y,rectangle_points_[2].X,rectangle_points_[2].Y); graphics.DrawLine(&pen,rectangle_points_[1].X,rectangle_points_[1].Y,rectangle_points_[3].X,rectangle_points_[3].Y); Gdiplus::GraphicsPath gpath_rectangle1; temp_path.AddPolygon(rectangle_points_, 4); temp_path.AddPath(&gpath_rectangle1, FALSE); gpath_rectangle1.Reset(); InvalidateRect(selected_rect_, false); drawing_mode_ = invalid; } if (is_move)//移動代碼 { SetCursor(h_move_); DrawRectangle1Gdiplus(rectangle_point_, CPoint(rectangle_point_[0].X, rectangle_point_[0].Y), point); StartPoint.X = rectangle_point_[0].X; StartPoint.Y = rectangle_point_[0].Y; EndPoint.X = point.x; EndPoint.Y = point.y; double dx,dy; dx=EndPoint.X-StartPoint.X; dy=EndPoint.Y-StartPoint.Y; rectangle_point_[0].X=rectangle_point_[0].X+dx; rectangle_point_[0].Y=rectangle_point_[0].Y+dy; rectangle_point_[1].X=rectangle_point_[1].X+dx; rectangle_point_[1].Y=rectangle_point_[1].Y+dy; rectangle_point_[2].X=rectangle_point_[2].X+dx; rectangle_point_[2].Y=rectangle_point_[2].Y+dy; rectangle_point_[3].X=rectangle_point_[3].X+dx; rectangle_point_[3].Y=rectangle_point_[3].Y+dy; Gdiplus::GraphicsPath gpath_rectangle; temp_path.AddPolygon(rectangle_point_, 4); temp_path.AddPath(&gpath_rectangle, FALSE); gpath_rectangle.Reset(); InvalidateRect(selected_rect_, false); drawing_mode_ = invalid; } }
在鼠標擡起添加以下代碼：
void CdrawtestDlg::OnLButtonUp(UINT nFlags, CPoint point) { // TODO: 在此添加消息處理程序代碼和/或調用默認值 GraphicsPath temp_path; if (is_draw) { if (drawing_mode_==drawingline) { drawing_mode_=invalid; temp_path.AddPath(gpath_line_,FALSE); gpath_line_->Reset(); } if (drawing_mode_ == drawingarrow) { GraphicsPath temp_arrow_path; temp_arrow_path.AddPolygon(arrow_points_, 6); InvalidateRect(selected_rect_, false); drawing_mode_ = invalid; vec_arrow_drawcwlls_.push_back(DrawCell(pen_color_, pen_width_, &temp_arrow_path)); } if (drawing_mode_ == deawingrectangle) { Gdiplus::GraphicsPath gpath_rectangle; temp_path.AddPolygon(rectangle_point_, 4); temp_path.AddPath(&gpath_rectangle, FALSE); gpath_rectangle.Reset(); InvalidateRect(selected_rect_, false); drawing_mode_ = invalid; } if (drawing_mode_ == drawingellipse) { temp_path.AddEllipse(Rect(start_pt_.x, start_pt_.y, old_pt_.x - start_pt_.x, old_pt_.y - start_pt_.y)); InvalidateRect(selected_rect_, false); drawing_mode_ = invalid; } vec_drawcells_.push_back(DrawCell(pen_color_, pen_width_, &temp_path)); } if (is_selected) { if (is_move||is_scale||is_select) { Gdiplus::GraphicsPath gpath_rectangle; temp_path.AddPolygon(rectangle_point_, 4); temp_path.AddPath(&gpath_rectangle, FALSE); gpath_rectangle.Reset(); InvalidateRect(selected_rect_, false); drawing_mode_ = invalid; } if (is_Emove) { /*temp_path.AddEllipse(Rect(start_pt_.x, start_pt_.y, old_pt_.x - start_pt_.x, old_pt_.y - start_pt_.y)); InvalidateRect(selected_rect_, false); drawing_mode_ = invalid;*/ } } CDialogEx::OnLButtonUp(nFlags, point); }
並添加滾輪響應實現鼠標控制縮放：
BOOL CdrawtestDlg::OnMouseWheel(UINT nFlags, short zDelta, CPoint pt) { // TODO: 在此添加消息處理程序代碼和/或調用默認值 GraphicsPath temp_path; if (is_scale) { if (zDelta>0)//向上滾 { rectangle_point_[0].X=rectangle_point_[0].X-5; rectangle_point_[0].Y=rectangle_point_[0].Y-5; rectangle_point_[1].X=rectangle_point_[1].X+5; rectangle_point_[1].Y=rectangle_point_[1].Y-5; rectangle_point_[2].X=rectangle_point_[2].X+5; rectangle_point_[2].Y=rectangle_point_[2].Y+5; rectangle_point_[3].X=rectangle_point_[3].X-5; rectangle_point_[3].Y=rectangle_point_[3].Y+5; } if (zDelta<0)//向下滾 { //測試代碼 rectangle_point_[0].X=rectangle_point_[0].X+5; rectangle_point_[0].Y=rectangle_point_[0].Y+5; rectangle_point_[1].X=rectangle_point_[1].X-5; rectangle_point_[1].Y=rectangle_point_[1].Y+5; rectangle_point_[2].X=rectangle_point_[2].X-5; rectangle_point_[2].Y=rectangle_point_[2].Y-5; rectangle_point_[3].X=rectangle_point_[3].X+5; rectangle_point_[3].Y=rectangle_point_[3].Y-5; } } return CDialogEx::OnMouseWheel(nFlags, zDelta, pt); }
好了，這樣就可以實現鼠標控制移動，縮放，旋轉的功能！
程序下載鏈接：
http://download.csdn.net/download/weixin_38002417/10109488