|
My C# app calls a COM server but does not release it. What's Wrong? Urgent!
Please help!
Here is how I call it:
<code>
...
void SomeFunc1()
{
for (int i; i<10; i++)
{
SomeFunc2();
}
}
void SomeFunc2()
{
MyCOMLib.MyIFace mf = null;
try
{
mf = new MyCOMLib.MyIFace();
string myParam = "Here is some param";
MyCOMLib.MyIFace2 mf2 = mf.MyMethod(myParam);
mf2.MyProperty = 1;
}
catch()
...
}
</code>
|
|
|
|
|
Not really surprising.
Anyway, help the GC by doing stuff like mf2.Release() and mf = null;
(may be the issue is on your part btw : if you have a wrong apartment model, then the COM server is not released that easy).
How low can you go ?
(MS retrofuck)
|
|
|
|
|
The problem is that for some reason, even when COM interface
IUnknown derived C# compiler throuws at me:
MyCOMLib.MyIFace2 does not contain a definition for 'Release'
and assigning to null does not release it right away for sure.
How do I work this appartment thing?
|
|
|
|
|
O!  So GC does not release objects right away, does it?!
It looks like if I call GC.Collect(); objects do get released (not right there but in a couple of milsecs).
I'm assuming that means that my COM objects are fine and can be released just fine, right? Or is this GC.Collect(); a kind of cheating?
If not, why GC doesn't clear local vars right there on the spot like VB does (I think  ) ? When does it do it?
|
|
|
|
|
GC.Collect() is kinda hardcore. This method is not normally called by a client app, except in critical scenarios (huge memory needs, and so on). It's true that, from what I know from the Java GC, the GC has no good reason to release objects as soon as they are out of scope.
The fact that GC.Collect() has actually released your COM object is that it was a weak-reference in scope.
COM are normaly finely released.
How low can you go ?
(MS retrofuck)
|
|
|
|
|
Interesting! Thanks a lot.
Curious : what's "weak-reference"?
And what do you mean by "COM are normaly finely released"?
May be my english is not that good yet 
Do you think I still have to hunt for problem or it looks like it's fine. What do I do?
|
|
|
|
|
Here is an article [^]explaining how the GC works, and what is a weak reference.
You'll notice it's about Sun's GC. But when you know where the .NET virtual machine comes from...
How low can you go ?
(MS retrofuck)
|
|
|
|
|
Hi,
I'm trying to call functions exposed by a .Net application (exe, not dll) from a COM client. The problem is that the tlb generated by regasm (or tlbexp) doesn't have enough info. I assume I need to use some funky attributes, but I just can't find them.
Does anyone have an idea?
Thanks,
Bruno
|
|
|
|
|
ComVisible and ComSource
How low can you go ?
(MS retrofuck)
|
|
|
|
|
ComVisible determines if a class/method is visible to COM, but has no effect in exes. ComSource is linked to events; I don't need those. Am I missing something?
Also, can you please explain the last part? The one with "how low..".
|
|
|
|
|
Those are entry points. If you check out .NET samples, or google, you'll find implementations that might help you.
How low can you go ?
(MS retrofuck)
|
|
|
|
|
I'm totally new to programming so don't expect me to know anything =)
I've been trying to write a simple program too list all the installed fonts in a simple list,
This I've accomplished with this code:
FontFamily[] fontFamilies;
InstalledFontCollection installedFontCollection = new InstalledFontCollection();
// Get the array of FontFamily objects.
fontFamilies = installedFontCollection.Families;
int count = fontFamilies.Length;
for(int j = 0; j < count; ++j)
{
listView1.Items.Add(fontFamilies[j].Name);
}
It adds lines to the listView1.
How would I now continue with my project and try to get the fonts to display in their own typeface, since they now are printed using the default system font.
Cheers
|
|
|
|
|
Essentially iterating through your array, make sure you have a graphics object when doing this (e.g. - grfx):
<code>
Color c = Color.Black;
Brush brush = new SolidBrush(c);
float y = 0;
FontFamily[] aff = FontFamily.Families;
foreach (FontFamily ff in aff)
{
Font font = new Font(ff, 12);
grfx.DrawString(ff.Name, font, brush, 0, y);
y += font.GetHeight(grfx);
}
</code>
HTH
Nick Parker
The greatest lesson in life is to know that even fools are right sometimes. - Winston Churchill
|
|
|
|
|
using System;
using System.Drawing;
using System.Drawing.Text;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace FontViewer
{
///
/// Summary description for Form1.
///
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.TabControl tabControl1;
private System.Windows.Forms.TabPage tabPage1;
private System.Windows.Forms.ListView listView1;
private System.Windows.Forms.MainMenu mainMenu1;
private System.Windows.Forms.MenuItem menuItem1;
private System.Windows.Forms.MenuItem menuItem2;
private System.Windows.Forms.MenuItem menuItem3;
private System.Windows.Forms.ColumnHeader columnHeader1;
private System.Windows.Forms.ColumnHeader columnHeader2;
///
/// Required designer variable.
///
private System.ComponentModel.Container components = null;
public Form1()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
}
///
/// Clean up any resources being used.
///
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
///
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
///
private void InitializeComponent()
{
System.Configuration.AppSettingsReader configurationAppSettings = new System.Configuration.AppSettingsReader();
this.tabControl1 = new System.Windows.Forms.TabControl();
this.tabPage1 = new System.Windows.Forms.TabPage();
this.listView1 = new System.Windows.Forms.ListView();
this.columnHeader2 = new System.Windows.Forms.ColumnHeader();
this.mainMenu1 = new System.Windows.Forms.MainMenu();
this.menuItem1 = new System.Windows.Forms.MenuItem();
this.menuItem2 = new System.Windows.Forms.MenuItem();
this.menuItem3 = new System.Windows.Forms.MenuItem();
this.columnHeader1 = new System.Windows.Forms.ColumnHeader();
this.tabControl1.SuspendLayout();
this.tabPage1.SuspendLayout();
this.SuspendLayout();
//
// tabControl1
//
this.tabControl1.Controls.AddRange(new System.Windows.Forms.Control[] {
this.tabPage1});
this.tabControl1.Dock = System.Windows.Forms.DockStyle.Fill;
this.tabControl1.Name = "tabControl1";
this.tabControl1.SelectedIndex = 0;
this.tabControl1.Size = new System.Drawing.Size(624, 353);
this.tabControl1.TabIndex = 2;
//
// tabPage1
//
this.tabPage1.Controls.AddRange(new System.Windows.Forms.Control[] {
this.listView1});
this.tabPage1.Location = new System.Drawing.Point(4, 22);
this.tabPage1.Name = "tabPage1";
this.tabPage1.Size = new System.Drawing.Size(616, 327);
this.tabPage1.TabIndex = 0;
this.tabPage1.Text = "Installed Fonts";
//
// listView1
//
this.listView1.CausesValidation = false;
this.listView1.Columns.AddRange(new System.Windows.Forms.ColumnHeader[] {
this.columnHeader2});
this.listView1.Dock = System.Windows.Forms.DockStyle.Fill;
this.listView1.HeaderStyle = System.Windows.Forms.ColumnHeaderStyle.Nonclickable;
this.listView1.MultiSelect = false;
this.listView1.Name = "listView1";
this.listView1.Scrollable = ((bool)(configurationAppSettings.GetValue("listView1.Scrollable", typeof(bool))));
this.listView1.Size = new System.Drawing.Size(616, 327);
this.listView1.Sorting = System.Windows.Forms.SortOrder.Ascending;
this.listView1.TabIndex = 1;
this.listView1.View = System.Windows.Forms.View.Details;
//
// columnHeader2
//
this.columnHeader2.Text = "Names";
this.columnHeader2.Width = 595;
//
// mainMenu1
//
this.mainMenu1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
this.menuItem1,
this.menuItem3});
//
// menuItem1
//
this.menuItem1.Index = 0;
this.menuItem1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
this.menuItem2});
this.menuItem1.Text = "File";
//
// menuItem2
//
this.menuItem2.Index = 0;
this.menuItem2.Shortcut = System.Windows.Forms.Shortcut.CtrlQ;
this.menuItem2.Text = "Exit";
this.menuItem2.Click += new System.EventHandler(this.menuItem2_Click);
//
// menuItem3
//
this.menuItem3.Index = 1;
this.menuItem3.Text = "About";
this.menuItem3.Click += new System.EventHandler(this.menuItem3_Click);
//
// columnHeader1
//
this.columnHeader1.Width = 612;
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(624, 353);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.tabControl1});
this.Menu = this.mainMenu1;
this.Name = "Form1";
this.Text = "Leons Font Program";
this.Load += new System.EventHandler(this.Form1_Load);
this.tabControl1.ResumeLayout(false);
this.tabPage1.ResumeLayout(false);
this.ResumeLayout(false);
}
#endregion
///
/// The main entry point for the application.
///
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
private void Form1_Load(object sender, System.EventArgs e)
{
Graphics grfx = CreateGraphics();
Color c = Color.Black;
Brush brush = new SolidBrush(c);
float y = 0;
FontFamily[] aff = FontFamily.Families;
foreach (FontFamily ff in aff)
{
if(ff.IsStyleAvailable(FontStyle.Regular))
{
Font font = new Font(ff, 12);
grfx.DrawString(ff.Name, font, brush, 0, y);
y += font.GetHeight(grfx);
}
}
}
private void menuItem3_Click(object sender, System.EventArgs e)
{
MessageBox.Show("Made By Leon Radley, 2002");
}
private void menuItem2_Click(object sender, System.EventArgs e)
{
Application.Exit();
}
}
}
Here's my program, the problem is that nothing shows when I compile it... what have I done wrong?
|
|
|
|
|
From my C# application, I want to create a MS access database create tables and update it with the data that I receive from the network! Kinda the same way cd player (that comes with win2k) stores its records on an Access DB and retreives them back.
What technology should I use to accomplish this ?
Thanks
Regards,
Venet.
Donec eris felix, multos numerabis amicos.
|
|
|
|
|
Download the Jet .NET driver here[^].
How low can you go ?
(MS retrofuck)
|
|
|
|
|
Why not just use ADO.NET's System.Data.OleDB namespace? If it's already built-in to the .NET framework...why download the Jet.NET driver?
Norm Almond: I seen some GUI's in my life but WTF is this mess 
Leppie: I made an app for my sister and she wouldnt use it till it was colorful enough
Norm:good point leppie, from that statement I can only deduce that this GUI must be aimed at children
Leppie:My sister is 25
-Norm on the MailMagic GUI
|
|
|
|
|
The If is the important thing in what you say.
Excerpt from MSDN[^] : "To access an ODBC data source using ADO.NET, use the ODBC .NET Data Provider, which is available for download at http://msdn.microsoft.com/downloads."
This driver is native in .NET 1.1 however.
How low can you go ?
(MS retrofuck)
|
|
|
|
|
I agree that ODBC is not required to access a MSACCESS database, even though most MSACCESS implementations in the real world use ODBC.
It's true you have a OLEDB Jet data provider under OLEDB .NET. Even if I don't recommend it, this may well allow to do the job.;P
How low can you go ?
(MS retrofuck)
|
|
|
|
|
Hi all.
I builded my application at home with C# and I tried it on others computers but it doesn't work. Do you know if I need to install on each computer the pack of 20Mo (I would need autorisations)? Or is there any other way as just copying a few files ?
I have another question, is it possible to compile C# appz in binary as C++ does ? This would speed up and solve the problem of my first question...
Thanks by advance.
NitroD.
|
|
|
|
|
C# cannot compile down to native, that would defeat the object of the .NET Framework. Thus, yes, if you want to run a C# program on a PC other than the one you compiled on, you have to install the .NET Framework.
Paul
Why don't you take a good look at yourself and describe what you see - Led Zeppelin, Misty Mountain Hop
|
|
|
|
|
If you try to run a .NET app on a computer with no .NET run-time installed, then you get a dirty message box saying "missing mscoree.dll". This DLL is launched from the PE and hosts the CLR.
If the computer has a .NET run-time, but in a wrong version (it will happen as soon as .NET 1.1 is RC), then you'll get an explicit message box "cannot find C:\WINNT\Microsoft .NET\Framework\v1.1.0.3800".
( in this scenario, the user may try to launch the app with his .NET run-time thanks to either the creation or modification of an associated .config file in the same directory. Of course, if the app was compiled against .NET 1.1, there is no strict guarantee is works against a .NET 1.0 run-time just because you would change a config file).
And about native generation, the JIT produces native code. Use ngen.exe. With .NET 1.0, you must explicitely use ngen.exe in a separate cmdline, because there is no direct support of this in the IDE. ngen myapp.exe will generate a native image of the managed code in myapp.exe, and put it in the GAC (c:\winnt\assembly) ready for use.
How low can you go ?
(MS retrofuck)
|
|
|
|
|
I was afraid about that...Thanks Paul and Stephane. Java can be compiled in class or native code..I hope C# will be able of the same thing later...
|
|
|
|
|
I'm trying to get a form to pop-up when the user presses a hotkey. So far the form pops up OK, (I'm registering the hotkey, and issueing a form.Show(); from within a WndProc method that ). But the form that I show doesn't get keyboard focus...
Dave
|
|
|
|
|
Have you tried Form.ShowDialog(this);?
Paul
Why don't you take a good look at yourself and describe what you see - Led Zeppelin, Misty Mountain Hop
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
