无法从 C# 中的 HEX 获取负浮点值

Question

I have to read some hex data from a file. It works in C++ and Matlab but not in C# (which is the language I'm using).

One data is made of 4 bytes, per exemple: d0bd a7fa

In C++/Matlab I can get the right value: -1.3362

But in C# I get this: 62.663810729980469

Here here's the C# code I'm using:

int exp = 6;
b.BaseStream.Seek(pos, SeekOrigin.Begin);
uint getValAbs = b.ReadUInt32();
(the below formula comes from the file format)
float actualValue = (float)(getValAbs * (Math.Pow(2, exp - 32)));
actualValue = 62.663810729980469;

and in matlab its

Spec(:,isub)    = fread(fid,fnpts,'long') * pow2(subfexp-32);

and it gives me the right value...

Any idea?

Answer 1

The error is here:

b.ReadUInt32();

They are using 'long' that is signed , so

b.ReadInt32();