How to Read DXF file with acadsharp?

[farshadvl]

hi guys . I have used this code but get error : object references not set ....

using (DxfReader reader = new DxfReader(file, null))
{
CadDocument doc = reader.Read();
}

why? and what should I do?

[DomCR]

Hi @farshadvl,

This seems an error in the Reader, could you provide more information about the exception?
If you could provide the file that caused the error that would help a lot.

[farshadvl]

hi
this is error result :

•   $exception	{"Object reference not set to an instance of an object."}	System.NullReferenceException
  

•   Data	{System.Collections.ListDictionaryInternal}	System.Collections.IDictionary {System.Collections.ListDictionaryInternal}
  
    StackTrace	"   at ACadSharp.CadDocument.RegisterCollection[T](IObservableCollection`1 collection)\r\n   at ACadSharp.IO.CadDocumentBuilder.RegisterTables()\r\n   at ACadSharp.IO.DXF.DxfDocumentBuilder.BuildDocument()\r\n   at ACadSharp.IO.DxfReader.Read()\r\n   at KianSazehPiping.Forms.App.Form_DXF.button1_Click_1(Object sender, EventArgs e) in D:\\Source\\KianSazehPiping\\KianSazehPiping\\Forms\\App\\DXF.cs:line 1186"	string
  

•   TargetSite	{Void RegisterCollection[T](ACadSharp.IObservableCollection`1[T])}	System.Reflection.MethodBase {System.Reflection.RuntimeMethodInfo}
  

[DomCR]

Looking at the exception seems that one of the main tables in the document was null, this is usually caused because the version of the DXF is equal or lower than AC1009, there is a branch in development to fix this issue.

In the mean time you can try to use the methods ReadEntities or ReadTables to try to get the information that you want.

Hope this helps.

[farshadvl]

tnx man. I use nugetpackage and If you update that package I really appreciate it.

[DomCR]

I did a release 4 days ago, check that you have the latest version.

[farshadvl]

Hi DomCR I have update package to latest version ACadSharp -Version 2.3.1-beta
again it says object refrence.... when read dxf file :
CadDocument doc = DxfReader.Read(file);

can u check it.my dxf file here I have uploaded
4-FUG-16802-AAR61-N_Sht_1.zip

[farshadvl]

can you explain an example how to use ReadEntitiy?
How can I load dxf file into CadDocument an dafter that ReadEntities?

[DomCR]

I've added examples on how can you read the entities

ACadSharp/ACadSharp.Examples/ReaderExamples.cs

Line 40 in bdafc5f

public static void ReadEntitiesFromDxf(string file)

I've tested the method with your file, unfortunately the file does not follow the proper DXF format specified in the documentation and the polylines are not read, this is not the first time that I see this kind of dxf so I'll try to find a fix for this issue.

[DomCR]

• Read polylines for irregular DXF  #359

[DomCR]

Out of curiosity, could you provide the source of the file? I mean if is a public DXF generator that I can use to run some test.

[farshadvl]

Tnx man . I appreciate your response.
this file was generated from PDMS software. this DXF is output from this application.

[farshadvl]

Hi Dom I have read this dxf with this library:IxMilia
this is my code:
` DxfFile dxfFile = DxfFile.Load(file);

                    if (dxfFile != null)
                    {
                        foreach (DxfEntity entity in dxfFile.Entities)
                        {
                            if (entity.EntityType == DxfEntityType.Text)
                            {
                                var text = (DxfText)entity;
                                richTextBox1.Text += "[" + text.Location + "]" + text.Value + Environment.NewLine;
                            }
                        }

                    }`

[DomCR]

Hi @farshadvl,

I haven't used the library from IxMilia, but the latest master branch of ACadSharp should be able to read the file that you provided, here is an equivalent code for what you want to achieve.

	CadDocument doc = DxfReader.Read(test, this.onNotification);
	foreach (TextEntity text in doc.Entities.OfType<TextEntity>())
	{
		//Do something for each text entity
		text.Value = "New text value";
	}

If you are using the Nuget package let me know and I'll release an update.

Hope this helps.