Intptr Handle are not Garbage Collected - c#-4.0

Question

Native Window Handles are not garbage collected. So after searching on internet I came to know about SafeProcessHandle below on MSDN article. Tried to implement it but i am receiving 'System.Runtime.InteropServices.SEHException'
https://msdn.microsoft.com/en-us/library/system.runtime.interopservices.safehandle.aspx
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Threading;
namespace TestHandle
{
class Program
{
[DllImport("user32.dll")]
static extern IntPtr GetForegroundWindow();
[DllImport("user32.dll")]
static extern int GetWindowText(IntPtr hWnd, StringBuilder text, int count);
[DllImport("user32.dll", SetLastError = true)]
static extern int GetWindowThreadProcessId(IntPtr hWnd, out int lpdwProcessId);
static void Main(string[] args)
{
while (true)
{
IntPtr hWnd = GetForegroundWindow();
int processID = 0;
int threadID = GetWindowThreadProcessId(hWnd, out processID);
using (Process p = Process.GetProcessById(processID))
{
StringBuilder text = new StringBuilder(256);
GetWindowText(hWnd, text, 256);
Console.WriteLine(text.ToString());
}
Console.WriteLine(hWnd);
Thread.Sleep(100);
}
char tmp = 'q';
while (Console.Read() != tmp) ;
}
}
}
In order to obtain currently opened window, I am trying to implement it through Timer and also tried through while loop but it increases memory footprint and if i am designing a long running Console Application which works till PC is running then things are getting worse. Can someone help me on this?

Answer 1

GetForegroundWindow returns a window handle that you do not need to tidy up. The code shown in the question do not leak and has no need for safe handles. You use safe handles when you have a requirement to tidy up unmanaged resources. That is not the case here.
If indeed you do have a problem with a leak, it is not related to the code shown which does not need to be modified.
Update
Regarding your update it is pointless to obtain the process ID and a .net Process object. You don't use them. You can request the window text with the window handle, as indeed you do.
Nothing here suggests a leak of any unmanaged resource and nothing here requires safe handles. If process memory use grows then that would be the normal behaviour for a GC based process. Each time round the loop a new StringBuilder object is created.
The code can be much simpler:
StringBuilder text = new StringBuilder(256);
while (true)
{
IntPtr hWnd = GetForegroundWindow();
GetWindowText(hWnd, text, 256);
Console.WriteLine(text.ToString());
Console.WriteLine(hWnd);
Thread.Sleep(100);
}
Note that I am re-using a single StringBuilder object which will at least prevent steady increase of managed memory use.
You should also check return values of API calls for errors but I don't want to go into the detail of how to do that here.