====C#受信側=====
private struct Status{
public int Hp;
public int Mp;
public int Sp;
}
protected override void WndProc(ref Message m)
{
switch(m.Msg)
{
case 0x8101:
Status s = (Status)m.GetLParam(typeof(Status));
MessageBox.Show(m.LParam.ToString());
txtHp.Text = s.Hp.ToString();
txtMp.Text = s.Mp.ToString();
txtSp.Text = s.Sp.ToString();
break;
}
base.WndProc(ref m);
}

====結果====
txtHp.Text = 1244916
txtMp.Text = 1
txtSp.Text = 1360384