[DllImport("coredll.dll")]

public static extern int GetSystemMetrics(int nIndex);

//屏幕宽

int nWidth = GetSystemMetrics(0);

//屏幕高

int nHeight = GetSystemMetrics(1);

Point point = new Point((nWidth - this.Width) / 2, (nHeight this.Height) / 2);

this.Location = point;