GDI+学习之------ 画线、区域填充、写字

《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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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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：

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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

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



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

写字（SolidBrush）

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

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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);

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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。