C# Discussion Boards - CodeProject

Member 7681714-Aug-03 7:59

14-Aug-03 7:59

Thanks for your reply, Ista.

I tried that, but let's say I bring in the number 6000645657564980, and it gets garbled as 600064+E in the datagrid if I then convert it back to string,
whether in SQL or C#, it gives me back 6000640000000000. Any suggestions?

Re: DataGrid & Large Integers

Ista14-Aug-03 8:36

Ista

14-Aug-03 8:36

specify the column as a DataGridTextBoxColumn()

I'm not an expert yet, but I play one at work. Yeah and here too.

Null reference problem

vaslui14-Aug-03 3:56

vaslui

14-Aug-03 3:56

Did you have the same problem as I do now ? I call a member function of an object that must return an object, the member function works well it creates the object to be returned and even it returns the object but the caller does not receive anything. The strange part is that at debug time the caller actually receive the object, but when build and run the project everinthing goes wrong and I have the upper problem Cry | :((

pls help me

I'll show you some piece of code and I can show you more if necessary:

private void btnOk_Click(object sender, System.EventArgs e)<br />
{<br />
   if(txtUserName.Text.Equals(String.Empty))<br />
   {<br />
     MessageBox.Show("pls insert the username !!!");<br />
     return;<br />
   }<br />
   if(txtPassword.Text.Equals(String.Empty))<br />
   {<br />
     MessageBox.Show("pls insert a password !!!");<br />
     return;<br />
   }<br />
<br />
   if (componenta != null)<br />
   {<br />
     medic = componenta.MedicLogin(txtUserName.Text,txtPassword.Text);<br />
     if(medic != null)<br />
     {<br />
       lblData.Text = medic.FirstName;		<br />
     }<br />
     else<br />
     {<br />
       MessageBox.Show("medic null");<br />
       return;<br />
     }<br />
   }<br />
   else<br />
   {<br />
     MessageBox.Show("componeta nula");<br />
   }<br />
}

I must say also that in a console application the previous problem does not apear.

Re: Null reference problem

Frank Olorin Rizzi14-Aug-03 6:15

Frank Olorin Rizzi

14-Aug-03 6:15

I'm not sure if this is the routine that calls (and receives -in some cases- the null reference back) or if it is the one that is called (and sends back the null reference in some cases).

In either case, which line is the one where you find the null reference?

Since you mention that this problem doesn't appear in a console application...
...what is different in the trouble case vs the non-trouble one?
[I see a btnOK_Click name there, which seems to hint that this is part of a Win App project, with GUI and buttons and all that... maybe the case of a console application is much more simple, and the difference might be in some included library...]

F.O.R.

write XML CDATA

devvvy13-Aug-03 22:34

devvvy

13-Aug-03 22:34

Guys, can you do something like this?

CCustomObj obj = new CCustomObj();

XmlTextWriter wr = new XmlTextWriter("outputXml.xml", null);
wr.Formatting = Formatting.Indented;

wr.WriteStartDocument();

wr.WriteStartElement("GraphicCollection");
wr.WriteAttributeString("objID", "12345");
wr.WriteCData(obj); //Can you write the binary memory map/layout of the object with C#? And restore it later on? I know WriteCData(String) does not accept "byte". Any alternative?

wr.WriteEndElement();
wr.WriteEndDocument();

wr.Flush();

wr.Close();

Thanks

norm

adding color to a form's title

Member 50926213-Aug-03 22:03

Member 509262

13-Aug-03 22:03

if i have a form and it has a title of 'Test Application' and i want to change it to 'Test Application - UNREGISTERED' and have the UNREGISTERED in red, is this possible?

thanks,
Rob Tomson

--
There are 10 kinds of people. Those who understand binary and those who don't.

interesting find but why?

Member 50926213-Aug-03 21:01

Member 509262

13-Aug-03 21:01

i have a background image on my form and i wanted to put a transparent label on it. however, i noticed that a label cannot have it's backcolor changed to 'transparent'. so i created a groupbox and placed a label in it. i then changed to backcolor of the groupbox to 'transparent' and the label's backcolor is now transparent! what the heck? is this a 'feature' of the groupbox or is there some other way of making a label transparent that i don't know about?

Rob

--
There are 10 kinds of people. Those who understand binary and those who don't.

Re: interesting find but why?

Member 50926213-Aug-03 21:21

Member 509262

13-Aug-03 21:21

*UPDATE*

i believe i've come across a bug. try these steps:
create a groupbox on a form and set the backcolor to 'transparent'.....works great

now change the backcolor back to 'control', change the flatstyle to 'system', then try to set the backcolor to 'transparent'.....error 'Invalid property value.' okay, so it won't let you have a transparent background while the flatstyle is set to system.

so change the flatstyle back to 'normal' and change the backcolor to 'transparent'. then change the flatstyle to 'system'.....works!? but it's really buggy, the display in the groupbox fails to update and when the program is run the background of the groupbox is weirded out.

i'm NOT using csharp 2003 so i don't know if they've fixed this in the new version or not. did they? why can the backcolor not be transparent if the flatstyle is set to 'system'?

Rob Tomson

--
There are 10 kinds of people. Those who understand binary and those who don't.

Re: interesting find but why?

James T. Johnson14-Aug-03 7:48

James T. Johnson

14-Aug-03 7:48

Rob Tomson wrote:
why can the backcolor not be transparent if the flatstyle is set to 'system'?

When you set the FlatStyle property to System you are telling the Framework to always let the OS do the drawing for that control. To my knowledge either none or not all of the .NET enabled OSes support the Transparent style which would require the Framework to emulate your choice but that goes against telling the framework to let the OS draw the control.

James

"My words but a whisper -- your deafness a SHOUT.
I may make you feel but I can't make you think." - Thick as a Brick, Jethro Tull 1972

Re: interesting find but why?

Ista16-Aug-03 16:27

Ista

16-Aug-03 16:27

even if you do a SetStyle method in the constructor. It works for most controls so since a label is a derivative of the control class you would thinks so.

SetStyle must be done in the constructor only by the way

I'm not an expert yet, but I play one at work. Yeah and here too.

Event syntax

devvvy13-Aug-03 20:10

devvvy

13-Aug-03 20:10

Hi, having a little problem with Event syntax:

class SomeClass
{
public delegate int MyEventDelegate(int param);
public event MyEventDelegate MyEvent;

public int MyHandler(int param) {...};

public SomeClass()
{
MyEventDelegate d = new MyEventDelegate(this.MyHandler);
MyEvent += d; //Question: type (left side)= event, type (right side)=delegate (which is an "object" after code injected. But, it seems to me the type does match.
}

... the rest ...

};

Thanks!

norm

Re: Event syntax

Member 7681714-Aug-03 4:16

Member 76817

14-Aug-03 4:16

Hi Norm,

Try this:

class SomeClass
{
public delegate int MyEventDelegate(int param);
public event MyEventDelegate MyEvent;

public int MyHandler(int param)
{
MessageBox.Show("A number has been added!");
}

public SomeClass()
{

MyEvent += new MyEventDelegate(MyHandler);
SomeAddFunction(1, 2);

}

// To Call the Event
private void SomeAddFunction(int a, int b)
{
int c = a + b;
MyEvent(c); // This will fire the event
}

This is my first attempt at showing something on a message board, I hope it helps!

-Abraham

Re: Event syntax

devvvy14-Aug-03 4:59

devvvy

14-Aug-03 4:59

Thanks for feedback. However, I think perhaps there's a bit of misunderstanding here. I understand how to hook up event handlers with event and fire it and all that. I understand how the compiler injects code into the source and our "delegate" become a "class". What I do not understand is, however, the syntax:

int = int + int (the type matches, no problem)

But:

MyDelegate d = new MyDelegate(this.MyHandler);
this.MyEvent += d;

It seems to me type doesn't match up, here's why:

On LEFT SIDE of "+=", type is MyEvent --> It's an "event".
On RIGHT SIDE of "+=", type is MyDelegate --> It's a "delegate" (Of course it expands to a class).

How does it work? Or perhaps I'm asking too much. Sometimes, developers should just take it and code it. Thanks.

norm

Re: Event syntax

Member 7681714-Aug-03 5:29

Member 76817

14-Aug-03 5:29

I really hope someone with more experience than me can follow up on this:
I think what goes on in the back is that there is an overloaded operator that adds the delegate (or function pointer) to a collection or list (the event model?), what goes on is not really saying MyEvent(event) EQUALS MyDelegate(delegate type), but saying "add this delegate to my list of function pointers to call when I'm triggered".

Or maybe your last sentence really summed it up!

Re: Event syntax

Nick Parker14-Aug-03 7:47

Nick Parker

14-Aug-03 7:47

norm wrote:
MyDelegate d = new MyDelegate(this.MyHandler);
this.MyEvent += d;

The event hold a *linked-list* of delegates, d becomes an instance of that delegate and is added to the chain. This way, we check to make sure there are items in the *linked-list* and then fire the event:

void OnMyEvent(string str)
{
   if(MyEvent != null) // check to see if a delegate is registered
      MyEvent(str);
}

HTH

-Nick Parker

Re: Event syntax

Member 7681714-Aug-03 8:00

Member 76817

14-Aug-03 8:00

Woa! I wasn't that far off.. I shall celebrate with a cold one after work!

Re: Event syntax

devvvy15-Aug-03 20:05

devvvy

15-Aug-03 20:05

Thanks Nick. But you too, have misunderstood the question, or perhaps I didnt state it clearly enuf:

"MyDelegate d = new MyDelegate(this.MyHandler);
this.MyEvent += d;

The event hold a *linked-list* of delegates, d becomes an instance of that delegate and is added to the chain. This way, we check to make sure there are items in the *linked-list* and then fire the event:"

>> Yes, it holds a link list. But let me emphasize again:

"this.MyEvent" --> Type: event
"d" --> Type= delegate

I KNOW the syntax and that compiler expands delegates into class. Just don't understand how "type" on left/right side can be DIFFERENT. Did they overload "+=" operator on event?

norm

Question about SqlClientPermission - SecurityException

yboc13-Aug-03 20:06

yboc

13-Aug-03 20:06

I can run my C# .net application in the system I use to develop it, but when I deployed the application to a windows 2000 system with .netframework installed, I got below message:

System.Security.SecurityException: Request for the permission of type
System.Data.SqlClient.SqlClientPermission,System.Data, Version= 1.0.5000.0, Culture= neutral,
PublickeyToken=b77a5c561934e089 failed.
at System.Security.CodeAccessSecurityEngine.CheckHelper(PermissionSet grantedSet,PermissionSet deniedSet, CodeAccessPermission demand,PermissinToken permToken,
.....

It seems that I can't get the permission to access Sql server. Could you pls tell me how to resolve this issue? Can anyone help to let me know how to set the permission to the application / user ?

Thanks.
coby

Re: Question about SqlClientPermission - SecurityException

TigerNinja_29-Aug-03 20:23

TigerNinja_

29-Aug-03 20:23

Just curious, does the credentials in your connection string have the proper security access ?

R.Bischoff
.NET, Kommst du mit?

Re: Question about SqlClientPermission - SecurityException

Anonymous16-Sep-03 15:50

Anonymous

16-Sep-03 15:50

It seems that the issue is because the .net framework can't get the permission to run sql store procedure locally. What I can saw is the connection string can get the server and uid but the pwd is cut. Actually, I did nothing to cut it in the program. Really strange, isn't it?

Windows Tab Loopong Question C#

mamaflynny13-Aug-03 19:58

mamaflynny

13-Aug-03 19:58

In my application I have say, twenty tabs, that I either want to show or hide based on the value provided in a ComboBox.
Call them ATab1 Atab2...ATab20. Is it possible for me to create some looping thing so that I can go through a loop based
based on the number provided in the Combo box (also 1 to 20) ?

mamaflynny

Re: Windows Tab Loopong Question C#

Frank Olorin Rizzi14-Aug-03 6:18

Frank Olorin Rizzi

14-Aug-03 6:18

...hmmm.. not sure, but
...why not have an Array of tabs (indexed 0 through 19)
and loop by that?

I implemented this solution for a series of Image boxes,
so I'm not sure if it would work nicely for tabs...

HTH,
F.O.R.

XML parsing

devvvy13-Aug-03 18:17

devvvy

13-Aug-03 18:17

Hi, having some problem parsing XML. How do I print the name of an XML attribute?

<sometag attriba="AAA" attribb="BBB">
SomeText

if(reader.NodeType==XmlNodeType.Element)
{
Console.Write("Element: {0}", tr.Name);

for(int i=0; i

Re: XML parsing

Manster14-Aug-03 5:26

Manster

14-Aug-03 5:26

Norm,
I've been able to pull the names of elements and attributes from an xml file using xpath. The code below will help you do it. Don't forget to add: using System.Xml.XPath;

XmlTextReader xtr = new XmlTextReader( m_sXmlFilePreferences );

while( xtr.Read() )
{
switch( xtr.NodeType )
{
case XmlNodeType.Attribute:
break;
case XmlNodeType.Element:

if( xtr.HasAttributes )
{
if( xtr.Name == "Preferences" )
{
for( int i = 0; i < xtr.AttributeCount; i++ )
{
xtr.MoveToAttribute( i );

if( xtr.Name == "EmailAddress" )
{
m_sEmailAddress = xtr.Value;

txt_Email.Text = m_sEmailAddress;
}

if( xtr.Name == "UpdateAutomatically" && xtr.Value == "true" )
{
m_bUpdateInvestments = true;

checkBox1.Checked = true;
}
if( xtr.Name == "UseEncryption" && xtr.Value == "true" )
{
m_bUseEncryption = true;

checkBox2.Checked = true;
}

if( xtr.Name == "PlayAlerts" && xtr.Value == "true" )
{
m_bPlayAlerts = true;

checkBox3.Checked = true;
} }
}
} // HasAttributes
break;
case XmlNodeType.Text:
break;
case XmlNodeType.CDATA:
break;
case XmlNodeType.ProcessingInstruction:
break;
case XmlNodeType.Comment:
break;
case XmlNodeType.XmlDeclaration:
break;
case XmlNodeType.Document:
break;
case XmlNodeType.DocumentType:
break;
case XmlNodeType.EntityReference:
break;
case XmlNodeType.EndElement:
break;
default :
break;

The structure of the xml file is as follows:

EmailAddress="youremailadderess@yourisp.com"
UpdateAutomatically="true" UseEncryption="true"
PlayAlerts="true"

I hope this helps. Smile | :)

Re: XML parsing

devvvy14-Aug-03 5:28

devvvy

14-Aug-03 5:28

Thanks I've got it - I neglected MoveToAttribute()

norm

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