dxfFileOperator.rar_dxf_c++builderdxf_c++dxf_dxf_dxfbuilde

共28个文件

cpp：14个

h：14个

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DXF（Drawing Exchange Format）文件是AutoCAD软件广泛使用的二维矢量图形格式，它允许不同设计软件之间交换图形数据。本文将深入探讨如何在C++ Builder环境下操作DXF文件，包括文件的读取和显示。理解DXF文件结构至关重要。DXF文件基于ASCII文本，分为多个部分，如头部（HEADER）、图层（LAYER）、线型（LTYPE）、实体（ENTITIES）和结束（EOF）。每个部分都有特定的标记和数据结构，用于定义图形元素，如点、线、圆、文字等。在C++ Builder中处理DXF文件，我们需要创建一个类来解析这些文件。这个类可以包含一系列方法，用于读取文件的不同部分。例如，`loadHeader()`方法用于读取文件头部信息，获取版本、单位等设置；`loadLayers()`方法则用于解析图层信息，包括颜色、线型等；`loadEntities()`则是核心方法，负责解析实际的图形实体。解析实体时，需要识别并处理各种图形元素。例如，线条（LINE）、圆（CIRCLE）、弧形（ARC）、多段线（POLYLINE）等。每个元素都有其特定的属性，如起点、终点、半径、角度等，这些都需要根据DXF格式的规范进行解码。显示DXF文件通常需要一个图形界面，如VCL或FireMonkey组件。C++ Builder提供了丰富的控件，如TCanvas，用于绘制2D图形。在读取DXF文件后，我们可以遍历解析出的实体，使用TCanvas的绘图函数，如`MoveTo()`、`LineTo()`、`Circle()`等，将它们绘制到界面上。对于更复杂的元素，如多段线和弧形，可能需要额外的计算步骤来确保精确绘制。为了优化性能和内存使用，我们还可以考虑使用缓冲区或图形加速技术。例如，可以先将DXF实体转换为屏幕坐标，然后一次性绘制到内存画布，最后再将此画布显示到界面上。此外，C++ Builder支持第三方库，如FreeDWG库，可以简化DXF文件的读写工作。这类库通常提供API接口，可以直接调用来处理DXF文件，避免了手动解析文件的复杂性。处理DXF文件在C++ Builder中涉及到文件I/O操作、字符串解析、图形绘制等多个方面。通过创建一个自定义的DXF解析类，并结合C++ Builder的图形界面功能，可以实现高效、准确地读取和显示DXF文件。对于复杂的项目，考虑使用现有的库可以显著提高开发效率。在实践中，不断学习和熟悉DXF格式的细节，以及C++ Builder的图形编程技巧，是提升工作效率的关键。

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dxfFileOperator.rar （28个子文件）

dxfFileOperator

dxfImport.cpp 21KB

dxfCadArc.cpp 3KB

dxfcadtext.h 1KB

dxfGeometry.cpp 7KB

dxfcadpoint.cpp 1KB

DxfShowControl.h 2KB

dxfElement.cpp 1KB

DxfGeometry.h 2KB

dxfcadBlock.h 1KB

dxfcadpolyline.cpp 3KB

dxfcadline.h 928B

dxfCadLayer.cpp 1KB

dxfCadLayer.h 854B

dxfcadpoint.h 757B

DxfShowControl.cpp 4KB

dxfImport.h 1KB

dxfDataSet.h 492B

dxfcadinsert.cpp 1KB

dxfcadarc.h 1KB

dxfCadBlock.cpp 3KB

dxfDataSet.cpp 452B

dxfcadpolyline.h 1KB

dxfcadline.cpp 2KB

dxfCadText.cpp 3KB

dxfKeySet.cpp 1KB

dxfElement.h 914B

dxfcadinsert.h 711B

dxfKeySet.h 646B

//-------------------------------------------------- #include <Classes.hpp> #include <stdio.h> #include <Forms.hpp> #include "dxfImport.h" #include "StdioFile.h" DxfImport::DxfImport() { } double DxfImport::StringToDouble(AnsiString value) { char *tempbuff; int len, i, dotpos; double ret; len = value.Length(); tempbuff = new char[len+1]; strcpy(tempbuff, value.c_str()); if (*tempbuff == '-' || *tempbuff == '+' || *tempbuff == '.') i = 1; else i = 0; for (; i<len; i++) { if ( !isdigit(*(tempbuff + i)) && *(tempbuff + i) != '.' ) { delete tempbuff; return 0; } } try { ret = atof(tempbuff); } catch(Exception &e) { ret = 0; } delete tempbuff; return ret; } AnsiString DxfImport::kVal(KeySet * keyset, AnsiString Key ) { int i; for(i=0; i<keyset->Count(); i++) if(Key == keyset->Keys[i]->Key) return keyset->Keys[i]->Value; return ""; } int DxfImport::FindLayer(AnsiString Name ) { int i; for(i=0;i<Layer.Count();i++) if(Name == Layer.Layers[i]->Name) return i; return -1; } bool DxfImport::IsDXFCommand(AnsiString InText ) { if(InText=="POINT"||InText=="LINE"||InText=="POLYLINE"||InText=="CIRCLE"||InText=="ARC" || InText=="TEXT" || InText=="INSERT") return true; else return false; } bool DxfImport::PrepareDXFBlock( DataSet * MyKey, DxfCadBlock *block) { int p=0; bool isclosed=false; char tempbuff[200]; if(MyKey->Type=="POINT") { } else if(MyKey->Type=="LINE") { DxfCadLine line; line.P1.X = StringToDouble(kVal(&(MyKey->KeySets),"10")); line.P1.Y = StringToDouble(kVal(&(MyKey->KeySets),"20")); line.P2.X = StringToDouble(kVal(&(MyKey->KeySets),"11")); line.P2.Y = StringToDouble(kVal(&(MyKey->KeySets),"21")); if (!block->AddGraph(&line)) { sprintf(tempbuff, "BlockElements超过最大限值：%d", DXF_BLOCK_MAX_ELEMENTS); Application->MessageBox(tempbuff, "Dxf转换错误", MB_OK); return false; } } else if(MyKey->Type=="ARC") { DxfCadArc arc; arc.Center.X = StringToDouble(kVal(&(MyKey->KeySets),"10")); arc.Center.Y = StringToDouble(kVal(&(MyKey->KeySets),"20")); arc.Radius = StringToDouble(kVal(&(MyKey->KeySets),"40")); arc.Angle1 = StringToDouble(kVal(&(MyKey->KeySets),"50")); arc.Angle2 = StringToDouble(kVal(&(MyKey->KeySets),"51")); if (!block->AddGraph(&arc)) { sprintf(tempbuff, "BlockElements超过最大限值：%d", DXF_BLOCK_MAX_ELEMENTS); Application->MessageBox(tempbuff, "Dxf转换错误", MB_OK); return false; } } else if(MyKey->Type=="CIRCLE") { DxfCadArc circle; circle.Center.X= StringToDouble(kVal(&(MyKey->KeySets),"10")); circle.Center.Y= StringToDouble(kVal(&(MyKey->KeySets),"20")); circle.Radius = StringToDouble(kVal(&(MyKey->KeySets),"40")); circle.Angle1=0.0; circle.Angle2=360.0; if (!block->AddGraph(&circle)) { sprintf(tempbuff, "BlockElements超过最大限值：%d", DXF_BLOCK_MAX_ELEMENTS); Application->MessageBox(tempbuff, "Dxf转换错误", MB_OK); return false; } } else if(MyKey->Type=="POLYLINE") { DxfCadPolyLine poly; int index=0; while(stricmp(MyKey->KeySets.Keys[index]->Value, "VERTEX") && index < MyKey->KeySets.Count()-1) { if(MyKey->KeySets.Keys[index]->Key !="70") { int tempValue; tempValue = StringToDouble(MyKey->KeySets.Keys[index]->Value); if( tempValue ==1 ) { isclosed=true; break; } } index++; } while (p < MyKey->KeySets.Count()-1) { while( stricmp(MyKey->KeySets.Keys[p]->Value, "VERTEX") && ( p < MyKey->KeySets.Count()-1)) p=p+1; if(p<MyKey->KeySets.Count()-1) { while(stricmp(MyKey->KeySets.Keys[p]->Key, "10") && (p<MyKey->KeySets.Count()-1)) p=p+1; tagCadPoint tempoint; tempoint.X = StringToDouble(MyKey->KeySets.Keys[p]->Value); while(stricmp(MyKey->KeySets.Keys[p]->Key, "20") && (p<MyKey->KeySets.Count()-1)) p=p+1; tempoint.Y = StringToDouble(MyKey->KeySets.Keys[p]->Value); if (!poly.Push(&tempoint)) { char tempbuff[200]; sprintf(tempbuff, "Polyline超过最大点限值：%d", DXF_MAX_POINTS); Application->MessageBox(tempbuff, "Dxf转换错误", MB_OK); return false; } while(stricmp(MyKey->KeySets.Keys[p]->Key, "0") && (p<MyKey->KeySets.Count()-1)) p=p+1; } } if(isclosed==true && poly.m_iPoints > 0 ) { tagCadPoint tempoint; tempoint.X = poly.Points[0]->X; tempoint.Y = poly.Points[0]->Y; if (!poly.Push(&tempoint)) { char tempbuff[200]; sprintf(tempbuff, "Polyline超过最大点限值：%d", DXF_MAX_POINTS); Application->MessageBox(tempbuff, "Dxf转换错误", MB_OK); return false; } } if (!block->AddGraph(&poly)) { sprintf(tempbuff, "BlockElements超过最大限值：%d", DXF_BLOCK_MAX_ELEMENTS); Application->MessageBox(tempbuff, "Dxf转换错误", MB_OK); return false; } } return true; } bool DxfImport::PrepareDXFEntity( DataSet * MyKey) { long layerNo=0; long p=0; bool isclosed=false; char tempbuff[200]; DxfCadLine line; DxfCadArc arc; DxfCadArc circle; DxfCadText text; DxfCadPolyLine poly; layerNo =FindLayer(kVal(&(MyKey->KeySets),"8")); if (layerNo < 0) layerNo=0; if(MyKey->Type=="POINT") { } else if(MyKey->Type=="LINE") { line.LayerNo = layerNo; line.P1.X = StringToDouble(kVal(&(MyKey->KeySets),"10")); line.P1.Y = StringToDouble(kVal(&(MyKey->KeySets),"20")); line.P2.X = StringToDouble(kVal(&(MyKey->KeySets),"11")); line.P2.Y = StringToDouble(kVal(&(MyKey->KeySets),"21")); if (!Graph->AddGraph(&line)) { sprintf(tempbuff, "Graph超过最大限值：%d", DXF_MAX_GRAPHS); Application->MessageBox(tempbuff, "Dxf转换错误", MB_OK); return false; } } else if(MyKey->Type=="ARC") { arc.LayerNo = layerNo; arc.Center.X = StringToDouble(kVal(&(MyKey->KeySets),"10")); arc.Center.Y = StringToDouble(kVal(&(MyKey->KeySets),"20")); arc.Radius = StringToDouble(kVal(&(MyKey->KeySets),"40")); arc.Angle1 = StringToDouble(kVal(&(MyKey->KeySets),"50")); arc.Angle2 = StringToDouble(kVal(&(MyKey->KeySets),"51")); if (!Graph->AddGraph(&arc)) { sprintf(tempbuff, "Graph超过最大限值：%d", DXF_MAX_GRAPHS); Application->MessageBox(tempbuff, "Dxf转换错误", MB_OK); return false; } } else if(MyKey->Type=="CIRCLE") { circle.LayerNo = layerNo; circle.Center.X= StringToDouble(kVal(&(MyKey->KeySets),"10")); circle.Center.Y= StringToDouble(kVal(&(MyKey->KeySets),"20")); circle.Radius = StringToDouble(kVal(&(MyKey->KeySets),"40")); circle.Angle1=0.0; circle.Angle2=360.0; if (!Graph->AddGraph(&circle)) { sprintf(tempbuff, "Graph超过最大限值：%d", DXF_MAX_GRAPHS); Application->MessageBox(tempbuff, "Dxf转换错误", MB_OK); return false; } } else if(MyKey->Type=="TEXT") { text.LayerNo = layerNo; text.StartPoint.X= StringToDouble(kVal(&(MyKey->KeySets),"10")); text.Star