How to set the height of a window using c#?

Question

Is it possible to set the height of a window using the window handle or process handle?

I have the following so far, assume the application in question is notepad.

Process[] processes = Process.GetProcessesByName("notepad");

foreach (Process p in processes)
{

    if (p.MainWindowTitle == title)
    {

        handle = p.MainWindowHandle;

        while ((handle = p.MainWindowHandle) == IntPtr.Zero)
        {
            Thread.Sleep(1000);
            p.Refresh();
        }

        break;
    }

}

Can I make use of handle or p to set the height of the window?

Using the window handle, pinvoke GetWindowRect to get rect, modify the height and then pinvoke MoveWindow. — David Heffernan, Jun 26 '11 at 14:34

David Heffernan · Accepted Answer · 2014-08-29T05:35:01.217

This is how I would do it:

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;

namespace ConsoleApplication1
{
    class Program
    {
        [StructLayout(LayoutKind.Sequential)]
        public struct RECT
        {
            public int left;
            public int top;
            public int right;
            public int bottom;
        }

        [DllImport("user32.dll", SetLastError = true)]
        static extern bool GetWindowRect(IntPtr hWnd, ref RECT Rect);

        [DllImport("user32.dll", SetLastError = true)]
        static extern bool MoveWindow(IntPtr hWnd, int X, int Y, int Width, int Height, bool Repaint);

        static void Main(string[] args)
        {
            Process[] processes = Process.GetProcessesByName("notepad");
            foreach (Process p in processes)
            {
                IntPtr handle = p.MainWindowHandle;
                RECT Rect = new RECT();
                if (GetWindowRect(handle, ref Rect))
                    MoveWindow(handle, Rect.left, Rect.right, Rect.right-Rect.left, Rect.bottom-Rect.top + 50, true);
            }
        }
    }
}

While you can do it with SetWindowPos, and SetWindowPos is the newer and more capable API, MoveWindow is just easier to call.

Excellent! Works in Silverlight OOB (and probably elevated in-browser as well). Of course it will require FindWindow to get handle. — Konstantin Salavatov, Aug 07 '13 at 07:36
I think the Rect struct is wrong. It should be Left, Top, Right, Bottom — atomaras, Aug 28 '14 at 22:12

BFree · Answer 2 · 2011-06-26T14:49:43.583

You should be able to use the Win32 SetWindowPos function (use for both position and size). Here's a link for how to do it in C#.

Here's a quick sample. This will move notepad to (10,10) on the screen, and resize it to (450,450):

class Program
{
    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, SetWindowPosFlags uFlags);

    static void Main(string[] args)
    {
        Console.WriteLine("Start notepad and hit any key...");
        Console.ReadKey(true);
        Process[] processes = Process.GetProcessesByName("notepad");

        foreach (Process p in processes)
        {
            var handle = p.MainWindowHandle;

            SetWindowPos(handle, new IntPtr(SpecialWindowHandles.HWND_TOP), 10,10,450,450,SetWindowPosFlags.SWP_SHOWWINDOW);

            break;

        }

    }
}

public enum SpecialWindowHandles
{
    HWND_TOP = 0,
    HWND_BOTTOM = 1,
    HWND_TOPMOST = -1,
    HWND_NOTOPMOST = -2
}

[Flags]
public enum SetWindowPosFlags : uint
{
    SWP_ASYNCWINDOWPOS = 0x4000,

    SWP_DEFERERASE = 0x2000,

    SWP_DRAWFRAME = 0x0020,

    SWP_FRAMECHANGED = 0x0020,

    SWP_HIDEWINDOW = 0x0080,

    SWP_NOACTIVATE = 0x0010,

    SWP_NOCOPYBITS = 0x0100,

    SWP_NOMOVE = 0x0002,

    SWP_NOOWNERZORDER = 0x0200,

    SWP_NOREDRAW = 0x0008,

    SWP_NOREPOSITION = 0x0200,

    SWP_NOSENDCHANGING = 0x0400,

    SWP_NOSIZE = 0x0001,

    SWP_NOZORDER = 0x0004,

    SWP_SHOWWINDOW = 0x0040,
}

That is awesome! I'd like to leave the width of the window as the original width how can I do this? — Abs, Jun 26 '11 at 14:57
Call GetWindowRect. MoveWindow is easier to use than SetWindowPos. — David Heffernan, Jun 26 '11 at 15:12
@David - I am not familiar with that, maybe you can add an example? — Abs, Jun 26 '11 at 15:27
@Abs: Use the GetWindowRect function to get the size as David suggested, and use the width from that. See here: http://www.pinvoke.net/default.aspx/user32/getwindowrect.html — BFree, Jun 26 '11 at 15:28

How to set the height of a window using c#?

2 Answers2

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