How do I center a window onscreen in C#?

Question

I need a way to center the current window. So for example, if a user pushes a button, I want the window to center itself onscreen. I know you can use the startposition prope

Answer 1

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

Answer 2

In Windows Forms:

this.StartPosition = FormStartPosition.CenterScreen;

In WPF:

this.WindowStartupLocation = WindowStartupLocation.CenterScreen;

That's all you have to do...

Answer 3

Use Location property of the form. Set it to the desired top left point

desired x = (desktop_width - form_witdh)/2

desired y = (desktop_height - from_height)/2

Answer 4

Use this:

this.CenterToScreen();  // This will take care of the current form

Answer 5

A single line:

this.Location = new Point((Screen.PrimaryScreen.WorkingArea.Width - this.Width) / 2,
                          (Screen.PrimaryScreen.WorkingArea.Height - this.Height) / 2);

Answer 6

 Centering a form in runtime

1.Set following property of Form:
   -> StartPosition : CenterScreen
   -> WindowState: Normal

This will center the form at runtime but if form size is bigger then expected, do second step.

2. Add Custom Size after InitializeComponent();

public Form1()
{
    InitializeComponent();
    this.Size = new Size(800, 600);
}