C# Discussion Boards - CodeProject

Rickard Andersson²⁰17-Sep-03 10:46

17-Sep-03 10:46

hm.. is this for a ListView? It looks like you do this for a DataGrid?

Rickard Andersson
Here is my card, contact me later!
UIN: 50302279
Sonork: 37318
Interests: C++, ADO, SQL, Winsock, 0s and 1s

Windows service, OnShutDown not executed

EnkelIk16-Sep-03 23:18

EnkelIk

16-Sep-03 23:18

Hi all.

I have written a very simple windows service where I have made overrides for OnStart, OnStop and OnShutdown. In the properties I have set CanStop and CanShutdown to true. The only thing that is to be done at the moment is that when either event is fired a line should be written to the log.

This works fine for OnStart and OnStop but it's like OnShutdown is never executed. Can anyone tell me what I'm doing wrong? This is my code:

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.ServiceProcess;

namespace MyServiceTest
{
public class MyService : System.ServiceProcess.ServiceBase
{
private System.Diagnostics.EventLog eventLog1;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;

public MyService()
{
// This call is required by the Windows.Forms Component Designer.
InitializeComponent();

//Create event log
if(!System.Diagnostics.EventLog.SourceExists("MyServiceLogSourse"))
System.Diagnostics.EventLog.CreateEventSource("MyServiceLogSourse","MyServiceLog");

//register name of source
eventLog1.Source = "MyServiceLogSourse";
eventLog1.Log="MyServiceLog";
}

// The main entry point for the process
static void Main()
{
System.ServiceProcess.ServiceBase[] ServicesToRun;

// More than one user Service may run within the same process. To add
// another service to this process, change the following line to
// create a second service object. For example,
//
// ServicesToRun = New System.ServiceProcess.ServiceBase[] {new Service1(), new MySecondUserService()};
//
ServicesToRun = new System.ServiceProcess.ServiceBase[] { new MyService() };

System.ServiceProcess.ServiceBase.Run(ServicesToRun);
}

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.eventLog1 = new System.Diagnostics.EventLog();
((System.ComponentModel.ISupportInitialize)(this.eventLog1)).BeginInit();
//
// MyService
//
this.CanShutdown = true;
this.ServiceName = "MyService";
((System.ComponentModel.ISupportInitialize)(this.eventLog1)).EndInit();

}

/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}

/// <summary>
/// Set things in motion so your service can do its work.
/// </summary>
protected override void OnStart(string[] args)
{
// Write to log
eventLog1.WriteEntry("MyService starts");
}

/// <summary>
/// Stop this service.
/// </summary>
protected override void OnStop()
{
// Write to log
eventLog1.WriteEntry("MyService stops");
}
protected override void OnShutdown()
{
// Write to log
eventLog1.WriteEntry("MyService shutting down");
}

}
}

Thanks
/EnkelIk

Re: Windows service, OnShutDown not executed

EnkelIk16-Sep-03 23:36

EnkelIk

16-Sep-03 23:36

Sorry, left out a bit of information there: OnStart and OnStop executes when I start and stop the service manually. When I restart the computer OnStart is the only method that executes (when the service is automatically restarted); I expected at least OnShutdown to execute to.

/EnkelIk

Keyboard hooks - Problem

CyberKewl16-Sep-03 22:21

CyberKewl

16-Sep-03 22:21

I have a problem with keyboard hooks - every time i press hold the CTRL+SHIFT key for quite some time, my application will crash with the error message :

"An unhandled exception of type 'System.NullReferenceException' occurred in
system.windows.forms.dll

Additional information: Object reference not set to an instance of an
object."

I've searched high and low for a solution to this matter but to no avail. Here's the code that i am using, it is meant to disable keys like ALT+TAB, CTRL+ESC, etc:

protected delegate int LowLevelKeyboardProcDelegate(int nCode, int wParam, ref KBDLLHOOKSTRUCT lParam);

[ DllImport( "user32.dll", EntryPoint="SetWindowsHookExA", CharSet=CharSet.Ansi )]

protected static extern int SetWindowsHookEx(int idHook , LowLevelKeyboardProcDelegate lpfn, int hMod , int dwThreadId);

[ DllImport( "user32.dll")]
protected static extern int CallNextHookEx(int hHook,int nCode, int wParam, ref KBDLLHOOKSTRUCT lParam);

[ DllImport("user32.dll")]
protected static extern int UnhookWindowsHookEx(long hhook);

const int WH_KEYBOARD_LL = 13;
public struct KBDLLHOOKSTRUCT
{
public int vkCode;
int scanCode;
public int flags;
int time;
int dwExtraInfo;
}
protected int intLLKey = 0;

protected int LowLevelKeyboardProc(int nCode,int wParam,ref KBDLLHOOKSTRUCT lParam)
{
bool blnEat = false;

switch (wParam)
{
case 256:
case 257:
case 260:
case 261:
//Alt+Tab, Alt+Esc, Ctrl+Esc, Windows Key
if (((lParam.vkCode == 9) && (lParam.flags == 32))
|| ((lParam.vkCode == 27) && (lParam.flags == 32))
|| ((lParam.vkCode == 27) && (lParam.flags == 0))
|| ((lParam.vkCode == 91) && (lParam.flags == 1))
|| ((lParam.vkCode == 92) && (lParam.flags == 1))
|| ((true) && (lParam.flags == 32)))

{
blnEat = true;
}
break;
}
if (blnEat)
return 1;
else
{
return CallNextHookEx(0, nCode, wParam, ref lParam);
}
}
public void KeyboardHook()
{
intLLKey = SetWindowsHookEx(WH_KEYBOARD_LL, new LowLevelKeyboardProcDelegate(LowLevelKeyboardProc), System.Runtime.InteropServices.Marshal.GetHINSTANCE(System.Reflection.Assembly.GetExecutingAssembly().GetModules()[0]).ToInt32(),0);
}

unicode in c#

Anonymous16-Sep-03 21:13

Anonymous

16-Sep-03 21:13

Sir

i write a code in C#

char myChar='/u0634';

Console.WriteLine("Unicode Character is {0}",myChar);

but it not give the actual character of that unicode.

what's the problem pls any tell me.

Thanks in Advance.

Re: unicode in c#

Oleksandr Kucherenko17-Sep-03 0:02

Oleksandr Kucherenko

17-Sep-03 0:02

Hi!

Console automaticaly convert string to OEM encoding and then type it in console window...

that is why not all unicode charecters can be converted and shown in console window.

try to do the same on WindowForm...

Good Luck
Alex Kucherenko

One ScrollBar controls two DataViews

JoeGunchy16-Sep-03 14:40

JoeGunchy

16-Sep-03 14:40

I have two ListViews, DataGrids whatever, and they both contain data from 2 seperate datasets. I'd like to have a scrollbar on one view that when scrolled would automatically adjust the other view so they both stay in sync. Both datasets would contain the same number of rows. Can this be done with C#.NET?

Fairly easily?
Any help/sample code would be greatly appriciated!
Thanks Smile | :)

C# is the best

S^nyp16-Sep-03 12:13

S^nyp

16-Sep-03 12:13

C#, at least I think, is alot better than vc++6 since everything is soo easy to use and soo powerful. Smile | :)

<marquee>Universal Project... Soon to be a .net

Re: C# is the best

Rickard Andersson²⁰17-Sep-03 1:30

Rickard Andersson²⁰

17-Sep-03 1:30

So, you're saying that VB is better than C++?

Rickard Andersson
Here is my card, contact me later!
UIN: 50302279
Sonork: 37318
Interests: C++, ADO, SQL, Winsock, 0s and 1s

Re: C# is the best

S^nyp17-Sep-03 1:42

S^nyp

17-Sep-03 1:42

I'm not saying that since I myself is a c++ proggrammer. It's just that it is said that C# combines the power of c++ with the ease of vb, though I know that C# has some issues, I think that this will probably erase mfc and visual c++ 6 though it will be alive, it won't be the preffered language anymore, just wait a couple of years and you'll see how it will progress.
Wink | ;)

<marquee>Universal Project... Soon to be a .net

Re: C# is the best

Rickard Andersson²⁰17-Sep-03 2:42

Rickard Andersson²⁰

17-Sep-03 2:42

Snyp wrote:
I think that this will probably erase mfc and visual c++ 6 though it will be alive, it won't be the preffered language anymore, just wait a couple of years and you'll see how it will progress.

It will do progress, but will not erase C++, ever!

Rickard Andersson
Here is my card, contact me later!
UIN: 50302279
Sonork: 37318
Interests: C++, ADO, SQL, Winsock, 0s and 1s

Re: C# is the best

S^nyp17-Sep-03 11:06

S^nyp

17-Sep-03 11:06

GRR... I didn't say that it will KILL C++, I said that it won't be the preferred language...;)

<marquee>Universal Project... Soon to be a .net

Re: C# is the best

Rickard Andersson²⁰17-Sep-03 21:53

Rickard Andersson²⁰

17-Sep-03 21:53

Whatever, dude! Big Grin | :-D

Rickard Andersson
Here is my card, contact me later!
UIN: 50302279
Sonork: 37318
Interests: C++, ADO, SQL, Winsock, 0s and 1s

Re: C# is the best

S^nyp18-Sep-03 10:46

S^nyp

18-Sep-03 10:46

Ya ok

<marquee>Universal Project... Soon to be a .net

Embed WindowsMediaPlayer Problem

pahluwalia16-Sep-03 11:46

pahluwalia

16-Sep-03 11:46

Hi ,
I am trying to add a WindowsMediaPlayer Control in my app so that the user can play the audio file from my app page ! I have added the ref to WMPLib.dll.

My code is as follows:

AxWMPLib.AxWindowsMediaPlayer newMedia = new AxWMPLib.AxWindowsMediaPlayer();

ResourceManager resources = new ResourceManager(typeof(testControl));
newMedia.OcxState = ((AxHost.State)(resources.GetObject("newMedia.OcxState")));

newMedia.Enabled = true;
newMedia.Location = new Point(tX, tY);
newMedia.Name = tName;
newMedia.Size = new Size(tW, tH);
thisPanel.Controls.Add(newMedia);
if (tDefault != null) newMedia.URL = tDefault;

newMedia.URL = @"c:\myfile.mp3";

The last line newMedia.URL = @"c:\myfile.mp3" results in InvalidActiveXStateException. I know the filename is correct as I can play it from Explorer.

Any suggestions Confused | :confused:

!?!

Thanks,
Paul

Simple/Stupid Casting Question

MKlucher16-Sep-03 11:13

MKlucher

16-Sep-03 11:13

In ASP (Code behind module) I'm tring to so a simple assignment of a dropdownlist value to an int but it can't convert the string to int. So how would I cast this?

<br />
dgResult.PageSize = ddlPageResults.SelectedValue;<br />

I tried (INT) but that's C++ I couln't do the ToInt32 either it didn't look like. I know this is super simple but I couln't find an aswer.

Re: Simple/Stupid Casting Question

Travis D. Mathison16-Sep-03 11:43

Travis D. Mathison

16-Sep-03 11:43

Try converting the string to int with the Int32.Parse() method.

Re: Simple/Stupid Casting Question

Braulio Dez16-Sep-03 21:04

Braulio Dez

16-Sep-03 21:04

Hi,

you can try:

<br />
try {<br />
  int MyInt = Convert.ToInt32(MyString); // Try to convert whatever to int<br />
}<br />
catch(Exception ex)<br />
{<br />
// Hey That was not a number !<br />
}<br />

Good Luck !
Braulio

ReEdit Data freezes Controls; No Edition possible

STW16-Sep-03 11:01

STW

16-Sep-03 11:01

I have Data in a typed DataSet and a Form to Edit it.
First Time I edit the Data with the form everything works fine. But if I want to reedit the Data, as I first changes something by the form everything freezes, means that I can't change data in any Control on the form. Even the OK, Cancel Buttons doesn't work anymore. I have to exit by the Close Button of the Form.

Any Ideas?

HOW TO SPREAD TEXT OVER COLUMNS IN A LISTVIEW IN C#

ARTURO CAJINA16-Sep-03 9:57

ARTURO CAJINA

16-Sep-03 9:57

hi,Does anyone know how to spread text over columns in a listview in c#?

THIS is EASY IN C++ .you ONLY have TO SET the SetItemData Method of the CListCtrl to 0.
IF you WANT text TO BE DISPLAYED IN COLUMNS SET SetItemData to 1.

example:

m_ListCtrl.SetItemData(0,0); //this lines makes text spread over columns

m_ListCtrl.SetItemData(0,1); //text to be displayed column by column

how can this be accomplished in c#?

thanks

Re: HOW TO SPREAD TEXT OVER COLUMNS IN A LISTVIEW IN C#

Alvaro Mendez17-Sep-03 5:58

Alvaro Mendez

17-Sep-03 5:58

I personally haven't worked with ListView controls in C#, but I did a quick search in MSDN and found a property called "Tag" in the ListViewItem class which may serve your purpose.

Regards,
Alvaro

Hey! It compiles! Ship it.

Wait Cursor

Joel Matthias16-Sep-03 9:52

Joel Matthias

16-Sep-03 9:52

Has anybody determined how to set the cursor to a wait cursor during a long operation where Application.DoEvents() is being called (and thus allowing .NET to reset the cursor to that set for the control the cursor is currently over).

The only solution I have found is to set the current cursor of every control to the wait cursor, but what a pain.

Thanks - Joel

VssConnect - Remote SourceSafe(r) Access http://www.voxcode.com[^]

Selected Checkbox...

.gonad16-Sep-03 9:28

.gonad

16-Sep-03 9:28

Hi.

i have a few checkboxes on my form and i want to show a simple messagebox when one of those checkboxes are checked. how can i do this dynamically?

for instance, instead of writing an if statement per checkbox, like this:

if(checkbox1.checked = true)<br />
{<br />
  MessageBox.Show("checked");<br />
}

write it dynamically, like this:
(the <selected checkbox=""> is the name of the selected checkbox)

if(<selected checkbox>.checked = true)<br />
{<br />
  MessageBox.Show("checked");<br />
}

i know this is pretty easy for all you guru friends out there. Smile | :)

Thanks,

.gonad.

Re: Selected Checkbox...

Tomas Petricek16-Sep-03 9:44

Tomas Petricek

16-Sep-03 9:44

I'm not sure if I understand you, but you can maybe use first parameter of your event handler method (sender). You have to set same function as event handler for all checkboxes.

private void checkBox1_CheckedChanged(object sender, System.EventArgs e)
{
  CheckBox checked=(CheckBox)sender;
  // checked is checkbox that was just checked/unchecked

}

i'm only pointer to myself

Re: Selected Checkbox...

.gonad16-Sep-03 10:46

.gonad

16-Sep-03 10:46

Hi.

Thanks for your help. this worked exactly as you said, but i do have a queston.

Can you explain what the
(CheckBox)sender
is specifying? also, can i use this for a textbox, or other controls, as well? for example,

TextBox tb = (TextBox)sender;

I'm new at this stuff, can't you tell?

Thanks again.

.gonad.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.