C# memory leak after calling another form

Question

Is This Problem Called Memory Leak? My Application include 5 Different Form. I Showing One of Them by Using this Code :

Form2 frm2 = new Form2();
frm2.ShowDlialog();
Form2 Includes : Buttons, TextBox, Lables, Listbox to Add Items Into the ListBox. (ADO.NET)

When frm2 Appears, It Get 1MB Memory (Based on Task Manager). After Closing Form2, The Memory Still High And it Does not Decrease. If I Call frm2.ShowDlialog() For Multiple Time, Application Memory Increased Every Time.

What I have tried:

I Searched in Google and tried :

Number 1 :

Form2 frm2 = new Form2();
frm2.ShowDlialog();
frm2.Dispose();

Number 2 : (in Form2_FormClosing)

GC.Collect();

Note: For example, When I Run Internet Download Manager software and open Dialog Form , The Memory Usage not Increased. What should I do to avoid Memory Leaks in My WinForms?

Answer 1

try using block to ensure the release of resources properly.
using (var frm2 = new Form2())
{
frm2.ShowDialog();
}

Answer 2

Hard to say without seeing the code for Form2. I would make sure you are removing any event handlers you add in code when the form is closing