vb.net write a .pdf but locks the file once it is written

Try

<...>
ReportName.Export()
ReportName.Close()
'---------------------------------------------------
ReportName = Nothing
myexportoptions = Nothing
mydiskfiledestinationoptions = Nothing

'---------------------------------------------------
SendMessage(myexportfile)
'System.IO.File.Delete(myexportfile)

BTW, do you get any error?

On the other hand a SendMessage() sub could cause this problem. Post your code here if the above does not help

I think this may be the code your looking for.

Private Sub StoreAirbill()
        'Declare and instantiate the dataset row.
        Dim sir As ShipmentInformation.ShipmentInformationRow

        'Ready dataset row for data insertion.
        sir = ShipmentInformationDataset.ShipmentInformation.NewRow

        'Databind dataset fields to form fields.
        sir.AirbillNumber = txtAirbillNumber.Text

        'Removed labels from form but left information incase I need to add it back.
        sir.Labels = ""
        sir.Origin = txtorigin.Text
        sir.Destination = txtdestination.Text
        sir.DeclaredValue = txtdeclaredvalue.Text
        sir.DeliveryDate = txtdate.Text
        sir.Time = txttime.Text
        sir.ShipperRefNumber = txtshipperref.Text
        sir.ConsigneeRefNumber = txtconsigneeref.Text
        sir.ThirdPartyRefNumber = txtthirdref.Text

        If optnextday.Checked = True Then
            sir.NextDay = "X"
        ElseIf opt2ndday.Checked = True Then
            sir.SecondDay = "X"
        ElseIf opt3to5day.Checked = True Then
            sir.Threeto5Day = "X"
        End If

        If Optshipper.Checked = True Then
            sir.Shipper = "X"
        ElseIf optconsignee.Checked = True Then
            sir.Consignee = "X"
        ElseIf optthirdparty.Checked = True Then
            sir.ThirdParty = "X"
        End If

        sir.ShipperName = txtShipperName.Text
        sir.ShipperAddress = txtshipperaddress.Text
        sir.ShipperCity = txtshippercity.Text
        sir.ShipperState = txtshipperstate.Text
        sir.ShipperZip = txtshipperzip.Text
        sir.ShipperContact = txtshippercontactname.Text
        sir.ShipperPhone = txtshippernumber.Text
        'sir.ShipperShow = txtShipperShow.Text
        'sir.ShipperBooth = txtShipperBooth.Text

        sir.ConsigneeName = cmbConsigneeName.Text
        sir.ConsigneeAddress = txtconsigneeaddress.Text
        sir.ConsigneeCity = txtconsigneecity.Text
        sir.ConsigneeState = txtconsigneestate.Text
        sir.ConsigneeZip = txtconsigneezip.Text
        sir.ConsigneeContact = txtconsigneecontactname.Text
        sir.ConsigneePhone = txtconsigneenumber.Text
        'sir.ConsigneeBooth = txtConsigneeBooth.Text
        'sir.ConsigneeBooth = txtConsigneeBooth.Text


        sir.ThirdName = cmbThirdPartyName.Text
        sir.ThirdAddress = txtthirdaddress.Text
        sir.ThirdCity = txtthirdcity.Text
        sir.ThirdState = txtthirdstate.Text
        sir.ThirdZip = txtthirdzip.Text
        sir.ThirdContact = txtthirdcontactname.Text
        sir.ThirdPhone = txtthirdnumber.Text

        sir.Pieces1 = txtPieces1.Text
        sir.Length1 = txtLength1.Text
        sir.Width1 = txtWidth1.Text
        sir.Height1 = txtHeight1.Text
        sir.Description1 = txtDescription1.Text
        sir.Weight1 = txtWeight1.Text

        sir.Pieces2 = txtPieces2.Text
        sir.Length2 = txtLength2.Text
        sir.Width2 = txtWidth2.Text
        sir.Height2 = txtHeight2.Text
        sir.Description2 = txtDescription2.Text
        sir.Weight2 = txtWeight2.Text

        sir.Pieces3 = txtPieces3.Text
        sir.Length3 = txtLength3.Text
        sir.Width3 = txtWidth3.Text
        sir.Height3 = txtHeight3.Text
        sir.Description3 = txtDescription3.Text
        sir.Weight3 = txtWeight3.Text

        sir.Pieces4 = txtPieces4.Text
        sir.Length4 = txtLength4.Text
        sir.Width4 = txtWidth4.Text
        sir.Height4 = txtHeight4.Text
        sir.Description4 = txtDescription4.Text
        sir.Weight4 = txtWeight4.Text

        sir.Instructions = txtSpecialInstructions.Text

        'Insert data to dataset.
        ShipmentInformationDataset.ShipmentInformation.Rows.Add(sir)

        'Print the airbill using information entered into the dataset.
        CreatePDF()


        'Clears all information out of the dataset to ready it for a new entry.
        ShipmentInformationDataset.Clear()

I don't see where you use the above code in a code provided in question.
Once again: do you get any error? If you do, show us the code raising error. If not, tell me how you know the file is locked?

Sorry, I had posted a response to your first post.  I must not have hit submit?  Anyway, yes I do get an error.  Here is what happens:  If I leave 'System.IO.File.Delete(myexportfile) uncommented then the first bill I process I get an error stating that System.IO.IOException the file you are trying to access is locked.  Now if I comment out that 'System.IO.File.Delete(myexportfile) then the first time I write a new bill number ( & txtAirbillNumber.Text &) it works fine and I can write as many as I want to.  But if I write a bill with the same AirBillNumber I get the error that the file I am trying to access isd locked.  Now I can open the folder that I'm writing the bills to and say I process 10 bills, If I right click and say delete on any of them, windows tells me thay are in use.  If I shut down the program and restart, then I can delete the bills.  I came home for lunch but I will post the code with the code you provided in it again.  With the code you provided, my result was the same.  I will also post the complete error I get.    Thanks again.

I did what you said last night.  So the bug was in my Sendmessage just as you said.  I added 'MyAttachment.Dispose()' to the end and now everything works as it should.  Thanks again for your help. :)

Glad to be helpful

And thanks for the points. They made me a VB.NET Master in EE :)