[RESOLVED] [2005] When 2 types equal

[tylerm]

I converted the C# code for the ICSharp Zip Library to VB.NET for unzipping and when I converted:

C#:

while ((objEntry = s.GetNextEntry()) != null) {}

to

VB.NET

While Not ((objEntry = s.GetNextEntry) Is Nothing)
End While

It throws an error at objEntry = s.GetNextEntry saying:

Operator '=' is not defined for types 'ICSharpCode.SharpZipLib.Zip.ZipEntry' and 'ICSharpCode.SharpZipLib.Zip.ZipEntry'

The C# code works perfect, any solutions?

[Atheist]

I think you need to rewrite it like this:

objEntry = s.GetNextEntry
      While Not objEntry Is Nothing
          'Do stuff...
          objEntry = s.GetNextEntry
      End While

EDIT: haha pressed the URL button instead of the code button

[tylerm]

Ok so that worked, but I noticed that if I have a sub folder in the zip, like:

\Root
..\Data
....\file2.txt
....\file3.txt
..\file1.txt

It will create the Data folder and file2 and 3 but not file1.

Converted Code:

Using s As ZipInputStream = New ZipInputStream(File.OpenRead(ImportPublisher_Path.Text))
            Dim objEntry As ZipEntry
            objEntry = s.GetNextEntry
            While Not objEntry Is Nothing
                objEntry = s.GetNextEntry
                Dim directoryName As String = Path.GetDirectoryName(objEntry.Name)
                Dim fileName As String = Path.GetFileName(objEntry.Name)
                If directoryName.Length > 0 Then
                    Directory.CreateDirectory(directoryName)
                End If
                If Not (fileName = String.Empty) Then
                    Using streamWriter As FileStream = File.Create(objEntry.Name)
                        Dim size As Integer = 2048
                        Dim data As Byte() = New Byte(2048) {}
                        While True
                            size = s.Read(data, 0, data.Length)
                            If size > 0 Then
                                streamWriter.Write(data, 0, size)
                            Else
                                Exit While
                            End If
                        End While
 
                    End Using
                End If
            End While
 
        End Using

Orginal C# code:

using (ZipInputStream s = new ZipInputStream(File.OpenRead(args[0]))) {
        
            ZipEntry theEntry;
            while ((theEntry = s.GetNextEntry()) != null) {
                
                Console.WriteLine(theEntry.Name);
                
                string directoryName = Path.GetDirectoryName(theEntry.Name);
                string fileName      = Path.GetFileName(theEntry.Name);
                
                // create directory
                if ( directoryName.Length > 0 ) {
                    Directory.CreateDirectory(directoryName);
                }
                
                if (fileName != String.Empty) {
                    using (FileStream streamWriter = File.Create(theEntry.Name)) {
                    
                        int size = 2048;
                        byte[] data = new byte[2048];
                        while (true) {
                            size = s.Read(data, 0, data.Length);
                            if (size > 0) {
                                streamWriter.Write(data, 0, size);
                            } else {
                                break;
                            }
                        }
                    }
                }
            }
        }

[jmcilhinney]

The reason that that is legal in C# is because in C-based languages an assignment statement has a return value. All assignments return the value that was assigned. In VB assignments do NOT return a value, so you must do as Atheist says and perform two steps. You have to perform the assignment first, then test the value of the variable that was assigned to.

[Atheist]

Yeah if you look at my previous post again, you see that I have commented the code with "Do stuff", and after that I have the objEntry = s.GetNextEntry line.
Thats how you need to do aswell, inside this while-loop, the objEntry = s.GetNextEntry line has to be the last line and not the first, or else it will skip the first "Entry" that is returned by the GetNextEntry function.

[tylerm]

Ok, that worked perfect, thanks alot guys!