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

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

2、连接线--------DrawLines

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  1. Pen blackPen(Color(255, 0, 0, 0), 3);  
  2.   
  3. PointF point1(10.0f, 10.0f);  
  4. PointF point2(10.0f, 100.0f);  
  5. PointF point3(200.0f, 50.0f);  
  6. PointF point4(250.0f, 80.0f);  
  7.   
  8. PointF points[4] = {point1, point2, point3, point4};  
  9. PointF* pPoints = points;  
  10.   
  11. 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

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

4、一次画多个矩形----DrawRectangles

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

5、画曲线-----DrawCurve

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  1. Pen greenPen(Color::Green, 3);  
  2. PointF point1(100.0f, 100.0f);  
  3. PointF point2(200.0f, 50.0f);  
  4. PointF point3(400.0f, 10.0f);  
  5. PointF point4(500.0f, 100.0f);  
  6.   
  7. PointF curvePoints[4] = {  
  8.     point1,  
  9.     point2,  
  10.     point3,  
  11.     point4};  
  12.   
  13.     PointF* pcurvePoints = curvePoints;  
  14.   
  15.     // 画曲线  
  16.     graphics.DrawCurve(&greenPen, curvePoints, 4);  
  17.   
  18.     //画连接点和直线连接线  
  19.     SolidBrush redBrush(Color::Red);  
  20.     graphics.FillEllipse(&redBrush, Rect(95, 95, 10, 10));//画连接点  
  21.     graphics.FillEllipse(&redBrush, Rect(195, 45, 10, 10));  
  22.     graphics.FillEllipse(&redBrush, Rect(395, 5, 10, 10));  
  23.     graphics.FillEllipse(&redBrush, Rect(495, 95, 10, 10));  
  24.   
  25.     Pen redPen(Color::Red, 2);  
  26.     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

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  1. Pen greenPen(Color::Green, 3);  
  2. PointF point1(100.0f, 100.0f);//开始点  
  3. PointF point2(200.0f, 50.0f);  
  4. PointF point3(400.0f, 10.0f);  
  5. PointF point4(500.0f, 100.0f);  
  6. PointF point5(600.0f, 200.0f);  
  7. PointF point6(700.0f, 400.0f);  
  8. PointF point7(500.0f, 500.0f);//结束点  
  9.   
  10. PointF curvePoints[7] = {  
  11.     point1,  
  12.     point2,  
  13.     point3,  
  14.     point4,  
  15.     point5,  
  16.     point6,  
  17.     point7};  
  18.   
  19.     PointF* pcurvePoints = curvePoints;  
  20.   
  21.     //画闭合曲线  
  22.     graphics.DrawClosedCurve(&greenPen, curvePoints, 7);  
  23.   
  24.     //画连接点  
  25.     SolidBrush redBrush(Color::Red);  
  26.     SolidBrush startBrush(Color::Blue);  
  27.     SolidBrush endBrush(Color::Black);  
  28.     graphics.FillEllipse(&startBrush, Rect(95, 95, 10, 10));  
  29.     graphics.FillEllipse(&redBrush, Rect(495, 95, 10, 10));  
  30.     graphics.FillEllipse(&redBrush, Rect(195, 45, 10, 10));  
  31.     graphics.FillEllipse(&redBrush, Rect(395, 5, 10, 10));  
  32.     graphics.FillEllipse(&redBrush, Rect(595, 195, 10, 10));  
  33.     graphics.FillEllipse(&redBrush, Rect(695, 395, 10, 10));  
  34.     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

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

8、画弧线----DrawArc

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

9、画扇形----DrawPie

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  1. Pen blackPen(Color(255, 0, 255, 0), 3);  
  2.   
  3. // 定义椭圆,然后在里面截一部分作为最终的扇形  
  4. RectF ellipseRect(0, 0, 200, 100);  
  5. REAL startAngle = 40.0f;  
  6. REAL sweepAngle = 100.0f;  
  7.   
  8. //画扇形  
  9. 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

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  1. SolidBrush blackBrush(Color(255, 0, 0, 0));  
  2.   
  3. PointF point1(100.0f, 100.0f);  
  4. PointF point2(200.0f, 50.0f);  
  5. PointF point3(250.0f, 200.0f);  
  6. PointF point4(50.0f, 150.0f);  
  7. PointF points[4] = {point1, point2, point3, point4};  
  8.   
  9. //填充闭合区域  
  10. graphics.FillClosedCurve(&blackBrush, points, 4);  
  11. //为闭合区域画边框  
  12. Pen curPen(Color::Green,3);  
  13. 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

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  1. SolidBrush blackBrush(Color(255, 0, 0, 0));  
  2. RectF ellipseRect(0.0f, 0.6f, 200.8f, 100.9f);  
  3. //填充椭圆  
  4. graphics.FillEllipse(&blackBrush, ellipseRect);  
  5. //画边框,当然也可以不画  
  6. Pen borderPen(Color::Green,3);  
  7. 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:

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  1. FillPie(Brush* brush, RectF& rect, REAL startAngle, REAL sweepAngle)    //填充扇形,对应DrawPie  
  2.   
  3. FillPolygon(Brush* brush, PointF* points, INT count)                       //填充多边形,对应DrawPolygon  
  4.   
  5. FillRectangle(Brush* brush, RectF& rect)                                          //填充矩形,对应DrawRectangle  
  6.   
  7. 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

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  1. Status FillPath( const Brush* brush, const GraphicsPath*path);  
  2.   
  3. 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);

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  1. Graphics graphics(this->GetDC()->m_hDC);  
  2.   
  3. SolidBrush brush(Color(255,0,0,255));  
  4.   
  5. FontFamily fontfamily(L"宋体");  
  6. Font font(&fontfamily,24,FontStyleRegular,UnitPixel);  
  7.   
  8. PointF  pointf(0,0);//PointF类对点进行了封装,这里是指定写字的开始点  
  9.   
  10. graphics.DrawString(L"GDI写字",-1,&font,pointf,&brush);  
  11. //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);

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  1. WCHAR string[256];  
  2. wcscpy(string, L"Sample Text");  
  3.   
  4. // Initialize arguments.  
  5. Font myFont(L"Arial", 16);//字体  
  6. RectF layoutRect(0.0f, 0.0f, 200.0f, 50.0f);//矩形  
  7.   
  8. //设定字体格式  
  9. StringFormat format;  
  10. format.SetAlignment(StringAlignmentCenter); //水平方向的对齐方式,这里设置为水平居中  
  11. format.SetLineAlignment(StringAlignmentFar);//垂直方向的对齐方式,这里设置为垂直居下  
  12. SolidBrush blackBrush(Color(255, 0, 0, 0));  
  13.   
  14. //画矩形边框  
  15. graphics.DrawRectangle(&Pen(Color::Green, 3), layoutRect);  
  16. //填充矩形背景  
  17. graphics.FillRectangle(&SolidBrush(Color(255,255,0,0)),layoutRect);  
  18. //DrawString,一定要先画背景再写字,要不然,字会被背景覆盖  
  19. graphics.DrawString(  
  20.     string,  
  21.     wcslen(string),  
  22.     &myFont,  
  23.     layoutRect,  
  24.     &format,  
  25.     &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。


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