Re: Dynamically Created AX Control not released.

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

This the normal behavior, every dll loaded in a process must be explicitly
unloaded, this is not done automatically.
For COM dll's (like OCX) the dll is loaded in a compatible apartment (STA
for an OCX) by the CLR COM interop layer, and is unloaded when the apartment
is torn down, that is when your main UI thread ends.
When you need this to be deterministic you will have to load the DLL
yourself, by calling "CoLoadLibrary", and unload it when done by calling
CoUnloadLibrary.
Another option would be to call CoFreeUnusedLibraryEx, that way you don't
need to call CoLoadLibrary yourself, but I don't know it's a good idea to
remove DLL's that were previously loaded by the CLR.

Willy.



"talon2112" <talon2112@xxxxxxxxx> wrote in message
news:1119028617.795136.227590@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>I am dynamically creating ActiveX controls on WinForms in VS.Net 2003.
>
> While this code works great, the OCX file that serves the Active X
> control does not get released until after the application has exited.
>
> This is a fairly significant issue for our software as we are actually
> trying to delete the file and replace it with a different copy. Anyone
> have any ideas on what is holding the file open and if there's any way
> to get at that object to shut it down?
>
>
> using System;
> using System.Drawing;
> using System.Collections;
> using System.ComponentModel;
> using System.Windows.Forms;
> using System.Data;
>
> namespace ocxtest
> {
> /// <summary>
> /// Summary description for Form1.
> /// </summary>
> public class Form1 : System.Windows.Forms.Form
> {
> private System.Windows.Forms.Button button1;
> private System.Windows.Forms.Button button2;
> private System.ComponentModel.Container components = null;
> public Form1()
> {
> //
> // Required for Windows Form Designer support
> //
> InitializeComponent();
> }
> protected override void Dispose( bool disposing )
> {
> if( disposing )
> {
> if (components != null)
> {
> components.Dispose();
> }
> }
> base.Dispose( disposing );
> }
>
> #region Windows Form Designer generated code
> /// <summary>
> /// Required method for Designer support - do not modify
> /// the contents of this method with the code editor.
> /// </summary>
> private void InitializeComponent()
> {
> this.button1 = new System.Windows.Forms.Button();
> this.button2 = new System.Windows.Forms.Button();
> this.SuspendLayout();
> //
> // button1
> //
> this.button1.Location = new System.Drawing.Point(432, 16);
> this.button1.Name = "button1";
> this.button1.Size = new System.Drawing.Size(80, 24);
> this.button1.TabIndex = 0;
> this.button1.Text = "button1";
> this.button1.Click += new
> System.EventHandler(this.button1_Click);
> //
> // button2
> //
> this.button2.Location = new System.Drawing.Point(432, 56);
> this.button2.Name = "button2";
> this.button2.Size = new System.Drawing.Size(80, 24);
> this.button2.TabIndex = 1;
> this.button2.Text = "button2";
> this.button2.Click += new
> System.EventHandler(this.button2_Click);
> //
> // Form1
> //
> this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
> this.ClientSize = new System.Drawing.Size(528, 270);
> this.Controls.Add(this.button2);
> this.Controls.Add(this.button1);
> this.Name = "Form1";
> this.Text = "Form1";
> this.ResumeLayout(false);
>
> }
> #endregion
>
> /// <summary>
> /// The main entry point for the application.
> /// </summary>
> [STAThread]
> static void Main()
> {
> Application.Run(new Form1());
> }
>
> private ActiveXControl ax ;
>
> private void button1_Click(object sender, System.EventArgs e)
> {
> Type t = Type.GetTypeFromProgID("a.ctl");
> ax = new ActiveXControl(t.GUID.ToString());
> this.Controls.Add(ax);
> ax.CreateControl();
> }
>
> private void button2_Click(object sender, System.EventArgs e)
> {
> this.Controls.Remove(ax);
> ax.Dispose();
> ax = null;
> }
> }
> public class ActiveXControl : System.Windows.Forms.AxHost
> {
> public ActiveXControl(string clsid) : base(clsid)
> {
> }
> protected override void Dispose(bool disposing)
> {
> if (disposing)
> {
> this.ContainingControl = null;
> }
> base.Dispose (disposing);
> }
> }
> }
>


.

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