C# Signatures:

// When calling with any variable parameters and Ansi
[DllImport("msvcrt.dll", CharSet = CharSet.Ansi,
    CallingConvention = CallingConvention.Cdecl)]
static extern int sprintf(
    StringBuilder buffer,
    string format,
    __arglist);

// When calling with any variable parameters and Unicode
[DllImport("msvcrt.dll", CharSet = CharSet.Unicode,
    CallingConvention = CallingConvention.Cdecl)]
static extern int swprintf(
    StringBuilder buffer,
    string format,
    __arglist);

// When calling with 1 arg
[DllImport("msvcrt.Dll", CallingConvention=CallingConvention.Cdecl)]
static extern int sprintf([In,Out]StringBuilder buffer, String fmt,
    String arg1);

// When calling with 2 args
[DllImport("msvcrt.Dll", CallingConvention=CallingConvention.Cdecl)]
static extern int sprintf([In,Out]StringBuilder buffer, String fmt,
    String arg1, String arg2);

// When calling with 3 args
[DllImport("msvcrt.Dll", CallingConvention=CallingConvention.Cdecl)]
static extern int sprintf([In,Out]StringBuilder buffer, String fmt,
    String arg1, String arg2, String arg3);

VB Signature:

<DllImport("msvcrt.dll", CharSet:=CharSet.Ansi,
  CallingConvention:=CallingConvention.Cdecl,
  ExactSpelling:=True)> _
  Public Shared Function sprintf(ByVal TargetString As System.Text.StringBuilder,
    ByVal  FormatSpecifier As String, ByVal i As Int32) As Int32
  End Function

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

StringBuilder buffer = new StringBuilder(255);

swprintf(buffer, "Greetings from thread %d\n", __arglist(Thread.CurrentThread.ManagedThreadId));

Console.WriteLine(buffer.ToString());

Alternative Managed API:

System.String.Format()