THPDFPage.DrawArc Method

THPDFPage.DrawArc

沿指定矩形限定的椭圆周长绘制弧线

Delphi 语法:

function DrawArc( X1, Y1, X2, Y2, X3, Y3, X4, Y4: Single ):TCurrPoint;

TCurrPoint Type Definition

THPDFCurrPoint defines a point in page coordinates

Unit
HPDFDoc

type
    THPDFCurrPoint = record
        X: Extended;
        Y: Extended;
    end;

说明:
The THPDFCurrPoint type defines a location on the PDF page. X specifies the horizontal coordinate and Y specifies the vertical coordinate.

C++ 语法:

TCurrPoint __fastcall DrawArc( float X1, float Y1, float X2, float Y2, float X3, float Y3, float X4, float Y4 );

说明

使用 DrawArc 绘制椭圆曲线。该弧沿由点 (X1,Y1) 与 (X2,Y2) 限定的椭圆周长绘制，并按逆时针方向从起点到终点。起点由椭圆与经过椭圆中心和 (X3,Y3) 的直线交点确定；终点由椭圆与经过椭圆中心和 (X4, Y4) 的直线交点确定

代码示例

program ArcExample;
{$APPTYPE CONSOLE}
uses
    SysUtils, Graphics, Classes, HPDFDoc;
var
    HPDF: THotPDF;
begin
    HPDF := THotPDF.Create( nil );
    try
        HPDF.AutoLaunch := true;                                                    // PDF file will be shown automatically
        HPDF.FileName := '.\Curve.pdf';                                             // Set PDF filename
        HPDF.BeginDoc;                                                              // Create PDF file
        HPDF.CurrentPage.DrawArc(10, 10, 110, 110, 50, 10, 10, 50); // Draw Arc
        HPDF.CurrentPage.Stroke;                                                    // Stroke curve
        HPDF.EndDoc;                                                                // Close PDF file
    finally
        HPDF.Free;
    end;
end.