int x = (System.Windows.Forms.SystemInformation.WorkingArea.Width - this.Size.Width) / 2;  int y = (System.Windows.Forms.SystemInformation.WorkingArea.Height - this.Size.Height) / 2;  this.StartPosition = FormStartPosition.Manual; //窗体的位置由Location属性决定  this.Location = (Point)new Size(x, y);         //窗体的起始位置为(x,y)

System.Windows.Forms.SystemInformation.WorkingArea.Width //屏幕宽度System.Windows.Forms.SystemInformation.WorkingArea.Height //屏幕高度（去系统任务栏，当显示有任务栏的时候）this.Size.Width   //自己窗体的宽度，this.Size.Width   //自己窗体的高度this.ClientRectangle.Width  //工作区域宽度this.ClientRectangle.Height  //工作区域高度设置窗口初始位置this.StartPosition = FormStartPosition.Manual; //窗体的位置由Location属性决定this.StartPosition = FormStartPosition.CenterParent; //窗体在其父窗体中居中this.StartPosition = FormStartPosition.CenterScreen; //窗体在当前显示窗口中居中，尺寸在窗体大小中指定this.StartPosition = FormStartPosition.WindowsDefaultBounds; //窗体定位在windows默认位置，边界也由windows默认决定this.StartPosition = FormStartPosition.WindowsDefaultLocation; //窗体定位在windows默认位置，尺寸在窗体大小中指定 

this.StartPosition = FormStartPosition.Manual; //窗体的位置由Location属性决定this.Location = (Point)new Size(0, 0); //窗体的起始位置为0,0 

this.ClientSize = new System.Drawing.Size(x1,y1); //X1 为宽度，Y1为高度

Rectangle rect = Screen.GetWorkingArea(this);Point p = new Point(rect.Width,rect.Height);this.Location = p;