Android Question Randomaccessfile: Reading unsigned integer

[grafsoft]

Hi,

I am reading an int with the readint method of RandomAccessFile. Now I have a negative integer, but what I need is an unsignedd int. I have trie3d to add different powers of 2, but to no avail.

Thanks for your help!

Peter

 

[DonManfred]

Using the forumsearch COULD HAVE HELPED. It is working!

Sub ToUnsigned(b As Byte) As Int
   Return Bit.And(0xFF, b)
End Sub

'check:
Log(Bit.ToHexString(ToUnsigned(0xAA)))

 

[Erel]

It is actually a bit more complicated to convert an int to unsigned int.
1. Add AndLong from here: https://www.b4x.com/android/forum/threads/bit-and-and-bit-or-for-longs.53755/#post-336996

2.

Sub ToUnsigned(i As Int) As Long
 Return AndLong(i, 0xFFFFFFFF)
End Sub

 

[grafsoft]

Thank you, but it does not work. Start, choose the number 1 and press OK. Line 80 in main.b4a.

 

[Erel]

Do you get any error?

 

[grafsoft]

No. But I have a value of -400818176, which is converted into -4.00818176E8

Unsigned should be positive, I think a value of about 7000 should come out.

 

[Erel]

Use this code:

Sub ToUnsigned(i As Int) As Long
   Return AndLong(i, 4294967295)
End Sub

 

[grafsoft]

Still does not work, produces -400818176. I made a little project that does only use this function and added it to this post.

 

[Erel]

Your code is wrong. The return type is Long. You cannot store the possible range of unsigned int values in an Int.

 

[grafsoft]

Thank you!