窗体在屏幕居中
this.SetBounds((Screen.GetBounds(this).Width / 2) - (this.Width / 2), (Screen.GetBounds(this).Height / 2) - (this.Height / 2), this.Width, this.Height, BoundsSpecified.Location);
this.SetBounds((Screen.GetBounds(this).Width / 2) - (this.Width / 2), (Screen.GetBounds(this).Height / 2) - (this.Height / 2), this.Width, this.Height, BoundsSpecified.Location);