Android Question Randomaccessfile: Reading unsigned integer

DonManfred

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• Jul 31, 2017

• #2

Using the forumsearch COULD HAVE HELPED. It is working!

B4X:

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

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

 

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Erel

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• Jul 31, 2017

• #3

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.

B4X:

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

 

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G

grafsoft

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• Aug 1, 2017

• #4

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

 

Attachments

• bintest.zip

  60.3 KB · Views: 378

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Erel

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• Aug 1, 2017

• #5

Do you get any error?

 

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G

grafsoft

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• Aug 1, 2017

• #6

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.

 

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Erel

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• Aug 1, 2017

• #7

Use this code:

B4X:

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

 

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G

grafsoft

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• Aug 2, 2017

• #8

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

 

Attachments

• test2.zip

  7.1 KB · Views: 348

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Erel

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• Aug 2, 2017

• #9

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

 

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G

grafsoft

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• Aug 2, 2017

• #10

Thank you!

 

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