using System; using System.Drawing; using System.Runtime.InteropServices; using System.Windows.Forms; namespace centrewindow { public partial class Form1 : Form { public struct RECT { public int Left; // x position of upper-left corner public int Top; // y position of upper-left corner public int Right; // x position of lower-right corner public int Bottom; // y position of lower-right corner } [DllImport("user32.dll")] public static extern IntPtr SetWindowPos(IntPtr hWnd, int hWndInsertAfter, int x, int Y, int cx, int cy, int wFlags); [DllImport("user32.dll")] public static extern bool GetWindowRect(HandleRef hwnd, out RECT lpRect); public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { CentreWindow(Handle, GetMonitorDimensions()); } private void CentreWindow(IntPtr handle, Size monitorDimensions) { RECT rect; GetWindowRect(new HandleRef(this, handle), out rect); var x1Pos = monitorDimensions.Width/2 - (rect.Right - rect.Left)/2; var x2Pos = rect.Right - rect.Left; var y1Pos = monitorDimensions.Height/2 - (rect.Bottom - rect.Top)/2; var y2Pos = rect.Bottom - rect.Top; SetWindowPos(handle, 0, x1Pos, y1Pos, x2Pos, y2Pos, 0); } private Size GetMonitorDimensions() { return SystemInformation.PrimaryMonitorSize; } } }
Centers any window you can get the handle of
StartPosition = FormStartPosition.CenterScreen;ORthis.CenterToScreen();