VectorDraw Developer Framework（VDF）是一個用於應用程序可視化的圖形引擎庫。有了VDF提供的功能，您可以輕鬆地創建、編輯、管理、輸出、輸入和打印2D和3D圖形文件。
VectorDraw web library (javascript)不僅能打開CAD圖紙，而且能顯示任何支持HTML5標準平臺上的通用矢量對象，如Windows，安卓，iOS和Linux。無需任何安裝，VectorDraw web library (javascript)就可以運行在任何支持canvas標籤和Javascript的主流瀏覽器（Chrome, Firefox, Safari, Opera, Dolphin, Boat等等）中。這意味着可以用DXF，DWG，DGN，SKP（Google的Sketchup），VDML等多種格式在任何臺式、平板電腦，智能手機和便攜式筆記本上展現出你的業務。
問：
透明度如何在VDF中發揮作用？
答：
在版本6023中，我們爲vdFigure對象添加了一個名爲TransparencyMethod的新屬性。此屬性從vdFigure.TransparencyMethodEnum獲取值，如下所示：
| TransparencyMethodEnum.ByLayer | 該對象採用透明度（AlphaBlending值）的顏色爲圖層pencolor AlphaBlending。 |
| TransparencyMethodEnum.ByBlock | 該對象獲取所有者的顏色透明度（AlphaBlending值）。所有者是一個帶有AlphaBlending筆顏的vdInsert。 |
| TransparencyMethodEnum.Default默認值 | 如果對象是真彩色，則對象將獲得自己的透明度值。如果筆觸是索引，則使用調色板的顏色透明度值。 |
| TransparencyMethodEnum.KeepOwn | 該對象總是採用它自己的pencolor透明度（AlphaBlending值）。 |
除此屬性外，還有Solid2dTransparency屬性，該屬性僅應用於陰影線/填充對象，並且僅應用於2D（線）模式，而不應用於3D（Wire3d / Shade / Hide / ShadeOn / Render）模式。因此，如果您希望填充的對象僅在2D而不是3D中透明，則可以使用此屬性。
另一方面，如果您希望對象在3D和2D模式下透明，則需要使用TransparencyMethod屬性並將AlphaBlending值設置爲vdFigure （KeepOwn，Default）或vdLayer（ByLayer）或parent（vdBlock）。AlphaBlending將值從0（完全透明，如不可見）取值到255（根本不透明）。
本方法適用於版本6.6023.x及更高版本，因爲以前的6023版本中不存在用於vdFigure的TransparencyMethod。
下面的代碼將向您演示對象的透明度如何在VDF中工作：
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
vdDocument doc;
private void Form1_Load(object sender, EventArgs e)
{
doc = vdFramedControl1.BaseControl.ActiveDocument;
}
private void button1_Click(object sender, EventArgs e)
{
//Transparency of vdCurves (line, polyline etc).
// For better display of this transparency a thicker line type is used in the code
doc.New();
vdRect rect = new vdRect(doc, new gPoint(0, 0, -0.1), 10, 2, 0);
rect.HatchProperties = new vdHatchProperties(VdConstFill.VdFillModeSolid);
doc.Model.Entities.AddItem(rect); // this is added just for better transparency display
// Using the transparency in the object by setting the AlphaBlending
vdCircle cir1 = new vdCircle(doc, new gPoint(2, 2), 1.0d);
cir1.LineWeight = VdConstLineWeight.LW_211;
cir1.PenColor.ColorIndex = 2;
cir1.PenColor.AlphaBlending = 120;
// the PenColor.AlphaBlending will be applied
cir1.TransparencyMethod = vdFigure.TransparencyMethodEnum.KeepOwn;
doc.Model.Entities.AddItem(cir1);
// Using the transparency in the Layer
vdLayer lay = new vdLayer(doc, "Transparent");
lay.PenColor.FromSystemColor(Color.Red); // layer is red !!!
lay.PenColor.AlphaBlending = 120; // setting layer's transparency
doc.Layers.AddItem(lay);
vdCircle cir2 = new vdCircle(doc, new gPoint(4.7, 2), 1.2d);
cir2.LineWeight = VdConstLineWeight.LW_200;
cir2.Layer = lay;
cir2.PenColor.ColorIndex = 2;
// but object is not colored by layer, only transparency is by layer here
// Layer's alpha blending wil be applied
cir2.TransparencyMethod = vdFigure.TransparencyMethodEnum.ByLayer;
doc.Model.Entities.AddItem(cir2);
// Using the transparency inside blocks/inserts
vdBlock blk = new vdBlock(doc, "Transparecy");
vdCircle cir3 = new vdCircle(doc, new gPoint(8, 2, 0), 1.5); // bigger circle
cir3.PenColor.ColorIndex = 2;
cir3.LineWeight = VdConstLineWeight.LW_158;
// the insert's Aplha blending will be applied
cir3.TransparencyMethod = vdFigure.TransparencyMethodEnum.ByBlock;
blk.Entities.AddItem(cir3);
cir3 = new vdCircle(doc, new gPoint(8, 2, 0), 0.7); //smaller circle
cir3.PenColor.ByBlock = true;
cir3.LineWeight = VdConstLineWeight.LW_158;
// the layer's Aplha blending will be applied which isn't transparent
cir3.TransparencyMethod = vdFigure.TransparencyMethodEnum.ByLayer;
blk.Entities.AddItem(cir3);
doc.Blocks.AddItem(blk);
vdInsert ins = new vdInsert(doc, blk, new gPoint(0, 0, 0), 0, 1, 1, 1);
// setting the inserts draw to use the Alpha Blending
ins.TransparencyMethod = vdFigure.TransparencyMethodEnum.Default;
ins.PenColor.FromSystemColor(Color.Yellow);
ins.PenColor.AlphaBlending = 120; // setting transparency to 120
doc.Model.Entities.AddItem(ins);
doc.Model.ZoomExtents(); doc.Redraw(true);
}
private void button2_Click(object sender, EventArgs e)
{
// Hatches/Filled objects and Transparency
doc.New();
vdRect rect = new vdRect(doc, new gPoint(0, 0, -0.1), 10, 2, 0);
rect.HatchProperties = new vdHatchProperties(VdConstFill.VdFillModeSolid);
doc.Model.Entities.AddItem(rect); // this is added just for better transparency display
// 2D Transparency Does NOT work in 3D modes (hide/shade/render/wire3D)
vdCircle cir1 = new vdCircle(doc, new gPoint(2, 2), 1.0d);
cir1.HatchProperties = new vdHatchProperties(VdConstFill.VdFillModeSolid);
cir1.HatchProperties.Solid2dTransparency = 80; // values 0 (invisible) to 255 (no transparency)
cir1.PenColor.FromSystemColor(Color.Red);
cir1.HatchProperties.FillColor.FromSystemColor(Color.Green);
doc.Model.Entities.AddItem(cir1);
// Transparency in PenColor work ALSO in 3D modes (hide/shade/render/wire3D)
vdCircle cir2 = new vdCircle(doc, new gPoint(4.7, 2), 1.2d);
cir2.HatchProperties = new vdHatchProperties(VdConstFill.VdFillModeSolid);
cir2.PenColor.FromSystemColor(Color.Green);
cir2.HatchProperties.FillColor.FromSystemColor(Color.Red);
cir2.HatchProperties.FillColor.AlphaBlending = 80;// values 0 (invisible) to 255 (no transparency)
doc.Model.Entities.AddItem(cir2);
// the above modes can be compbined with TransparencyMethod of vdfigure (that work in 3D modes), like
vdCircle cir3 = new vdCircle(doc, new gPoint(8, 2, 0), 1.5);
cir3.PenColor.ColorIndex = 4;
cir3.LineWeight = VdConstLineWeight.LW_200;
cir3.PenColor.AlphaBlending = 80;
cir3.HatchProperties = new vdHatchProperties(VdConstFill.VdFillModeSolid);
cir3.HatchProperties.FillColor.FromSystemColor(Color.Green);
cir3.HatchProperties.FillColor.AlphaBlending = 80;
cir3.TransparencyMethod = vdFigure.TransparencyMethodEnum.KeepOwn;
doc.Model.Entities.AddItem(cir3);
doc.Model.ZoomExtents(); doc.Redraw(true);
}
}