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c#winformsbinarywriter

Write empty bytes using binarywriter

so i am using binarywriter to write some strings over the original strings, but i need to overwrite the whole string in the binary file, so i am trying to write the new string, and overwrite the rest of the old string with 0x00 (empty bytes), this is what i tried, but not working:

bw.Write(enc.GetBytes(listView1.Items[i].SubItems[2].Text + (31 - enc.GetByteCount(listView1.Items[i].SubItems[2].Text)) * '\0'));

31 is the constant int that all old strings can't tresspass (don't ask me, it's a script thingy)

Solution

  • That's because: 

    number * '\0'
= number * 0  ('\0' converted to int)
=> always equal to 0

    To generate a string filled with \0 (or any char) of a certain length, use:

    new string(`\0`, number)

    In your case:

    string newStr = listView1.Items[i].SubItems[2].Text;
bw.Write(enc.GetBytes(newStr + new string('\0', (31 - enc.GetByteCount(newStr)))));