GDI+学习及代码总结之------画线、区域填充、写字

转自：http://blog.csdn.net/harvic880925/article/details/9023329

《精通GDI编程》里的代码，在学习过程中对它加以总结，以防以后用到，所有代码都是在MFC 单文档中实现的，写在View::OnDraw(CDC */*pDC*/)中

画线/边框（Pen）

1、画单线-------DrawLine

 Pen pen(Color(255,0,0,0),3);
 PointF L_PTStart(0,0);
 PointF L_PTEnd(100,10);
 graphics.DrawLine(&pen,L_PTStart,L_PTEnd);

2、连接线--------DrawLines

 Pen blackPen(Color(255, 0, 0, 0), 3);

 PointF point1(10.0f, 10.0f);
 PointF point2(10.0f, 100.0f);
 PointF point3(200.0f, 50.0f);
 PointF point4(250.0f, 80.0f);

 PointF points[4] = {point1, point2, point3, point4};
 PointF* pPoints = points;

 graphics.DrawLines(&blackPen, pPoints, 4);

讲解：points数组中的每个点都是连接线上的转折点，DrawLines会把它们按照顺序一个个连接起来

3、画矩形-----DrawRectangle,只画边框，不画背景色

 Pen blackPen(Color(255,255, 0, 0), 3);
 Rect rect(0, 0, 100, 100);
 graphics.DrawRectangle(&blackPen, rect);

4、一次画多个矩形----DrawRectangles

 Pen blackPen(Color(255, 0, 255, 0), 3);
 // 定义三个矩形
 RectF rect1(0.0f, 0.0f, 50.0f, 60.0f);
 RectF rect2(60.0f, 70.0f, 70.0f, 100.0f);
 RectF rect3(100.0f, 0.0f, 50.0f, 50.0f);
 RectF rects[] = {rect1, rect2, rect3};
 //RectF是对Rect的封装
 graphics.DrawRectangles(&blackPen, rects, 3);

5、画曲线-----DrawCurve

 Pen greenPen(Color::Green, 3);
 PointF point1(100.0f, 100.0f);
 PointF point2(200.0f, 50.0f);
 PointF point3(400.0f, 10.0f);
 PointF point4(500.0f, 100.0f);

 PointF curvePoints[4] = {
     point1,
     point2,
     point3,
     point4};

     PointF* pcurvePoints = curvePoints;

     // 画曲线
     graphics.DrawCurve(&greenPen, curvePoints, 4);

     //画连接点和直线连接线
     SolidBrush redBrush(Color::Red);
     graphics.FillEllipse(&redBrush, Rect(95, 95, 10, 10));//画连接点
     graphics.FillEllipse(&redBrush, Rect(195, 45, 10, 10));
     graphics.FillEllipse(&redBrush, Rect(395, 5, 10, 10));
     graphics.FillEllipse(&redBrush, Rect(495, 95, 10, 10));

     Pen redPen(Color::Red, 2);
     graphics.DrawLines(&redPen,curvePoints,4);//画连接线

注意：这里为了比较画曲线与画直线连接线的区别，我用绿色画的曲线，用红色画的直线连接线，同时画出了连接点，大家可以比较一下。

6、画闭合曲线

 Pen greenPen(Color::Green, 3);
 PointF point1(100.0f, 100.0f);//开始点
 PointF point2(200.0f, 50.0f);
 PointF point3(400.0f, 10.0f);
 PointF point4(500.0f, 100.0f);
 PointF point5(600.0f, 200.0f);
 PointF point6(700.0f, 400.0f);
 PointF point7(500.0f, 500.0f);//结束点

 PointF curvePoints[7] = {
     point1,
     point2,
     point3,
     point4,
     point5,
     point6,
     point7};

     PointF* pcurvePoints = curvePoints;

     //画闭合曲线
     graphics.DrawClosedCurve(&greenPen, curvePoints, 7);

     //画连接点
     SolidBrush redBrush(Color::Red);
     SolidBrush startBrush(Color::Blue);
     SolidBrush endBrush(Color::Black);
     graphics.FillEllipse(&startBrush, Rect(95, 95, 10, 10));
     graphics.FillEllipse(&redBrush, Rect(495, 95, 10, 10));
     graphics.FillEllipse(&redBrush, Rect(195, 45, 10, 10));
     graphics.FillEllipse(&redBrush, Rect(395, 5, 10, 10));
     graphics.FillEllipse(&redBrush, Rect(595, 195, 10, 10));
     graphics.FillEllipse(&redBrush, Rect(695, 395, 10, 10));
     graphics.FillEllipse(&endBrush, Rect(495, 495, 10, 10));

注意：蓝色点是开始点，黑色点是结束点
7、画多边形-----DrawPolygon，既然能画闭合的曲线，肯定也有闭合的直线，当然闭合的直线也就是所谓的多边形

 Pen blackPen(Color(255, 0, 0, 0), 3);
 //创建点数组，DrawPolygon会按这些点的顺序逐个连接起来
 PointF point1(100.0f, 100.0f);
 PointF point2(200.0f, 130.0f);
 PointF point3(150.0f, 200.0f);
 PointF point4(50.0f, 200.0f);
 PointF point5(0.0f, 130.0f);
 PointF points[5] = {point1, point2, point3, point4, point5};
 PointF* pPoints = points;
 // 画多边形，也就是闭合直线
 graphics.DrawPolygon(&blackPen, pPoints, 5);

8、画弧线----DrawArc

 Pen redPen(Color::Red, 3);
 RectF ellipseRect(0, 0, 200, 100);
 REAL startAngle = 0.0f;//起始度数
 REAL sweepAngle = 90.0f;//结尾时的度数
 // 画弧线
 graphics.DrawArc(&redPen, ellipseRect, startAngle, sweepAngle);
 //画出边框，做为参考
 Pen greenPen(Color::Green, 1);
 graphics.DrawRectangle(&greenPen,ellipseRect);

9、画扇形----DrawPie

 Pen blackPen(Color(255, 0, 255, 0), 3);

 // 定义椭圆，然后在里面截一部分作为最终的扇形
 RectF ellipseRect(0, 0, 200, 100);
 REAL startAngle = 40.0f;
 REAL sweepAngle = 100.0f;

 //画扇形
 graphics.DrawPie(&blackPen, ellipseRect, startAngle, sweepAngle);

先出效果图：

这里要对它两上名词讲解一下，什么叫startAngle(开始度数)，什么叫sweepAngle(范围度数也能叫扫过度数，我译的，嘿嘿)

看下MSDN里对DrawPie函数的讲解就会懂了，里面有这个图，给大家看一下

填充区域（SolidBrush）

1、填充闭合区域----FillClosedCurve，边框对应：DrawClosedCurve

 SolidBrush blackBrush(Color(255, 0, 0, 0));

 PointF point1(100.0f, 100.0f);
 PointF point2(200.0f, 50.0f);
 PointF point3(250.0f, 200.0f);
 PointF point4(50.0f, 150.0f);
 PointF points[4] = {point1, point2, point3, point4};

 //填充闭合区域
 graphics.FillClosedCurve(&blackBrush, points, 4);
 //为闭合区域画边框
 Pen curPen(Color::Green,3);
 graphics.DrawClosedCurve(&curPen,points,4);

注意：从结果图中也可以看出填充区域（背景）和边框是分离的，用FillClosedCurve来填充背景色，用DrawClosedCurve来画边框

2、填充椭圆---FillEllipse，边框对应：DrawEllipse

 SolidBrush blackBrush(Color(255, 0, 0, 0));
 RectF ellipseRect(0.0f, 0.6f, 200.8f, 100.9f);
 //填充椭圆
 graphics.FillEllipse(&blackBrush, ellipseRect);
 //画边框，当然也可以不画
 Pen borderPen(Color::Green,3);
 graphics.DrawEllipse(&borderPen,ellipseRect);

还有类似的几个函数，这里就不一 一讲解了

它们是：

 FillPie(Brush* brush, RectF& rect, REAL startAngle, REAL sweepAngle)    //填充扇形，对应DrawPie

 FillPolygon(Brush* brush, PointF* points, INT count)                       //填充多边形，对应DrawPolygon

 FillRectangle(Brush* brush, RectF& rect)                                          //填充矩形,对应DrawRectangle

 FillRectangles(Brush* brush, RectF* rects, INT count)                   //同时填充多个矩形，对应DrawRectangles

还有是关于路径和区域的，先记下，后面再说

 Status FillPath( const Brush* brush, const GraphicsPath*path);

 Status FillRegion( const Brush* brush, const Region*region);

写字（SolidBrush）

形式一：Status DrawString( const WCHAR*string, INTlength, const Font* font, const PointF&origin, const Brush*brush);

 Graphics graphics(this->GetDC()->m_hDC);

 SolidBrush brush(Color(255,0,0,255));

 FontFamily fontfamily(L"宋体");
 Font font(&fontfamily,24,FontStyleRegular,UnitPixel);

 PointF  pointf(0,0);//PointF类对点进行了封装，这里是指定写字的开始点

 graphics.DrawString(L"GDI写字",-1,&font,pointf,&brush);
 //DrawString还有另外两个重载形式，能实现更强大的功能

形式二：Status DrawString( const WCHAR*string, INT length, const Font*font, const RectF&layoutRect, const StringFormat*stringFormat, const Brush*brush);

 WCHAR string[256];
 wcscpy(string, L"Sample Text");

 // Initialize arguments.
 Font myFont(L"Arial", 16);//字体
 RectF layoutRect(0.0f, 0.0f, 200.0f, 50.0f);//矩形

 //设定字体格式
 StringFormat format;
 format.SetAlignment(StringAlignmentCenter); //水平方向的对齐方式，这里设置为水平居中
 format.SetLineAlignment(StringAlignmentFar);//垂直方向的对齐方式，这里设置为垂直居下
 SolidBrush blackBrush(Color(255, 0, 0, 0));

 //画矩形边框
 graphics.DrawRectangle(&Pen(Color::Green, 3), layoutRect);
 //填充矩形背景
 graphics.FillRectangle(&SolidBrush(Color(255,255,0,0)),layoutRect);
 //DrawString，一定要先画背景再写字，要不然，字会被背景覆盖
 graphics.DrawString(
     string,
     wcslen(string),
     &myFont,
     layoutRect,
     &format,
     &blackBrush);

形式三：Status DrawString( const WCHAR*string, INTlength, const Font* font, const PointF&origin, const StringFormat*stringFormat, const Brush* brush);

这种形式是形式一与形式二的结合，指定写字开始点和字体格式，这里就不举例了。