C# Discussion Boards - CodeProject

Re: having a long menu not taking all the screen height

dnewmon5-Dec-05 7:34

5-Dec-05 7:34

Allow the menu to close as normal when the arrows are selected, update the items, and make it appear in the same location again.

If you added the context menu to the control using the "ContextMenu" Property create a delegate for the MouseDown event and note the location of the mouse when the right mouse button is clicked.

Update the menu items, then call:
myCtrl.ContextMenu.Show(myCtrl, savedX, savedY);

David

Re: having a long menu not taking all the screen height

joebarthib5-Dec-05 21:31

joebarthib

5-Dec-05 21:31

Hi, thanks for your answer. That's a goog idea yes, I will try it. But I'm afraid the menu closing then re-opening will be unaesthetic.

Otherwise, I have found another solution on a French forum: http://www.csharpfr.com/code.aspx?ID=34929

This solution consists in using the SetMenuInfo API to set the maximum menu height. But you also need to create a new contextmenu class, as SetMenuInfo needs a handle, and the only valid handle can be obtained by calling CreateMenuhandle, which is a ContextMenu protected method!

RichTextBox Problems

alvinjv4-Dec-05 23:17

alvinjv

4-Dec-05 23:17

Considering that I'm a novice C# user there may be a very simple answer to this problem. I have 3 tabs in my application; one where the search parameters are entered and the second where the related file is displayed in a richtextBox. For some reason unless I view the richtextbox tab before I try load a file into it I am unable to view any loaded files. Any help in this regard would be appreciated.

Kind Regards,
Alvin

Re: RichTextBox Problems

S. Senthil Kumar5-Dec-05 4:17

S. Senthil Kumar

5-Dec-05 4:17

Some code would definitely help. Where are you instantiating the textbox?

Regards
Senthil
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adding and retrieving pictures

Mohammad Daba'an4-Dec-05 22:39

Mohammad Daba'an

4-Dec-05 22:39

hi, how can i save a real picture on the SQL DB and retrieve it through .net

Thanks alot
Hamody

The unexplainable, a DllNotFoundException

dxben4-Dec-05 22:33

dxben

4-Dec-05 22:33

I'm having a very odd problem. I have a basic C# form app that pInvokes into a C++ dll. When I build my C++ dll and C# app in Release mode, the C# app can load the dll and call into it just fine.

However if I build the solution in Debug mode, the C# app throws a DllNotFoundException. I've double checked and the C++ debug version of the dll is being properly copied into the C# app's bin/debug folder, so its actually there.

Why is it able to load the release version and not the debug version? Mad | :mad:

Re: The unexplainable, a DllNotFoundException

leppie5-Dec-05 7:20

leppie

5-Dec-05 7:20

dxben wrote:
I've double checked and the C++ debug version of the dll is being properly copied into the C# app's bin/debug folder, so its actually there.

And the name of the debug dll is the same?

^{xacc.ide-0.1 released! Download and screenshots}

Re: The unexplainable, a DllNotFoundException

dxben5-Dec-05 9:16

dxben

5-Dec-05 9:16

Yeah its the same. Actually someone else pointed out to me that my debug dll is probably dependent on the debug dll of the CRT and that it can't find it. So I need to make sure the debug DLL of CRT is in my path. What is the filename of the debug crt DLL?

question about remoting

savage_4-Dec-05 20:45

savage_

4-Dec-05 20:45

i have an object
public class Class2 : System.MarshalByRefObject
{
public Class2 ( ) { } // default constructor
public Class2 (string param1, string param2) { }
}

i cant use the 2nd constructor with remoting, when i use wsdl on the remoting url it doesnt have a signature for the 2nd constructor.

how do i implement this?

thanks

Re: question about remoting

S. Senthil Kumar5-Dec-05 4:15

S. Senthil Kumar

5-Dec-05 4:15

I guess you want an object instantiated with the second constructor to be registered with the remoting framework. If that's what you wanted to do, use the Marshal[^] method. Like

Class2 c2 = new Class2("x", "y");
RemotingServices.Marshal(c2,...);

Regards
Senthil
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Problem in EventHandling

Satish324-Dec-05 19:58

Satish32

4-Dec-05 19:58

HI,

I have a usercontrol with a testbox in it, and i am using "keydown" event of the textbox with in the control (for my specific functionality) .( i am using this control in my (win)form).

On form level i have one "Button". and i set "AcceptButton" property of form to this button.

My problem is, when i hit enter key while having focus on textbox of usecontrol, "Acceptbutton" property of form is executing instead of "keydown" event of usercontrol.

How do i make execute, "keydown" event of usercontrol on hitting enter key?

Regards,

satz

Re: Problem in EventHandling

S. Senthil Kumar5-Dec-05 4:11

S. Senthil Kumar

5-Dec-05 4:11

You can't get it to do both. AcceptButton is used to indicate the button that is to get the notification when the user presses Enter in the dialog.

Regards
Senthil
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bin and obj folder in C# windows application

nbobby4-Dec-05 19:27

nbobby

4-Dec-05 19:27

I have a trivial question.

When we create a C# windows application "bin" and "obj" folder is created in the project folder.
Will anyone please tell me that what is the signifance of these 2 folders.

Thanks a lot

Re: bin and obj folder in C# windows application

Heath Stewart4-Dec-05 19:47

Heath Stewart

4-Dec-05 19:47

The obj directory is a temporary directory. Visual Studio uses this for temporary files when compiling and linking. Files out of the bin directory are what you should deploy. This is the directory to which build variables like $(TargetPath) refer.

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Re: bin and obj folder in C# windows application

nbobby4-Dec-05 20:11

nbobby

4-Dec-05 20:11

Thanks Heath

I got your point

Re: bin and obj folder in C# windows application

har04mich5-Dec-05 6:52

har04mich

5-Dec-05 6:52

The bin (binaries) folder is the one you should be using. The obj folder is used to hold temp build files and for debugging purposes.
The bin folder has seperate directories for your build types and generally you want to build .pdb files with your release build in case you have to do any remote debugging.

urgent Help on C#

momoo4-Dec-05 19:24

momoo

4-Dec-05 19:24

Hi.. I'm currently doing a web design on the calendar using C# web application.I have created a calendar. I would like to ask that if i click the date on the calendar, can i retrieve the database?? I have tried several times and it seem like is not working. Below is my code, could anyone help me that if i missing on any parts?? Thanks!! My code:

.
.
.
using System.Data.SqlClient

private void Calendar1_SelectionChanged(object sender, System.EventArgs e)
{
TBDate1.Text = CAL1.SelectedDate.ToLongDateString();
SqlConnection conn=new SqlConnection("put my connection string here");
string seldate = "Select * from Particulars where DateField = '" + TBDate1.Text + "'";
SqlDataAdapter DA = new SqlDataAdapter(seldate,sqlConnection1);

DataSet DS = new DataSet();
DA.Fill(DS);
DataTable DT = new DataTable();
DataGrid1.DataSource=DS.Tables[0].DefaultView;
DataGrid1.DataBind();

}

Thanks for your help..;)

Cheers!

Re: urgent Help on C#

Heath Stewart4-Dec-05 19:40

Heath Stewart

4-Dec-05 19:40

First of all, never use string concatenation like that in SQL strings. All I have to do as an attacker is set the TBDate1.Text field (either in the page or via an HTTP GET or POST) to ' or 1=1; delete from Particulars; -- and your table is gone. With probing I could do worse, such as steal credit card information or other private information, etc. This is called a SQL injection attack and is one of the most overlooked vulnerabilities. Use parameterized queries using the SqlCommand.Parameters collection property.

That's also the answer to the problem here. Dates are typically surrounded by "#" (depending on the database management system) but using parameters eliminates having to know that:

SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "SELECT * FROM Particulars WHERE DateField = @Date";
cmd.Parameters.Add("@Date", SqlDbType.DateTime).Value = DateTime.Parse(TBDate1.Text);
// ...

Add some error-handling, though, since DateTime.Parse could fail if incorrectly formatted.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Customer Product-lifecycle Experience
Microsoft

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referring to Class Instance from other page

vikings4-Dec-05 17:46

vikings

4-Dec-05 17:46

Hello,

I've declared an instance of a class in the startup page of my app
eg Car mycar = new Car()

and have assigned various attributes into it.

I would like to refer to the instance mycar in other pages (either in the aspx or .cs )

eg mycar.model

I'm getting The type or namespace name 'mycar' could not be found (are you missing a using directive or an assembly reference?)

What's the best way to declare the instance of this class to my other pages?

thanks,

John

Re: referring to Class Instance from other page

Heath Stewart4-Dec-05 19:34

Heath Stewart

4-Dec-05 19:34

Pages are executed in separate threads, such that an instance of one page is not persistent so one page can't access the variable of another. Store singleton class instances in your Application object in global.asax or use a singleton. There's many ways to do this. You can find more suggestions in the ASP.NET forum.

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Developer Division Customer Product-lifecycle Experience
Microsoft

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Re: referring to Class Instance from other page

vikings4-Dec-05 19:50

vikings

4-Dec-05 19:50

thanks for your reply Heath,

Each user will have their own instance, with different properties - I assume a singleton is not appropriate?.

The class is declared in its own namespace.
Initially I referred to the class directly (rather than its instance) in other pages via the using 'namespace' entry. This worked, but each user overwrote the properties of the class!, hence of course I needed to use the class instance!.

I was hoping to reference the class instance in a similar way.

I may need to store the class instance in session (from the initial page), then retrieve it when needed.

thanks,

John

John

Re: referring to Class Instance from other page

Heath Stewart4-Dec-05 20:05

Heath Stewart

4-Dec-05 20:05

You only defined the class. An instance is created for each page request (even the same page in a different request, like after a post-back). This is crucial to how pages are executed in ASP.NET. If the object is to be stored per-user, store it in the Page.Session dictionary property instead. When the session expires the object will not be available. In you're using ASP.NET 2.0, look into the personalization feature. You can get an overview and read a tutorial at http://msdn.microsoft.com/library/en-us/dnvs05/html/person_fin.asp[^].

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Microsoft

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Re: referring to Class Instance from other page

nbobby4-Dec-05 19:46

nbobby

4-Dec-05 19:46

just use the namespace and the class then u will get the object of your class.

eg if

namespace WinTest
{
class abc{
public test mytest = new mytest();
}
}

class test
{
public int i;
}

now in class2 u can get the object as follows

WinTest.abc.mytest.i;

hope it will help

Re: referring to Class Instance from other page

vikings4-Dec-05 19:52

vikings

4-Dec-05 19:52

thanks nbobby,

this looks just like what I'm after.

best regards,

John

John

Re: referring to Class Instance from other page

Heath Stewart4-Dec-05 20:08

Heath Stewart

4-Dec-05 20:08

Keep in mind that this is a different instance, not the same instance created in the other page. A class and a class instance (as you mentioned in your subject) are two different things. Classes can be referred to from anywhere so long as the assembly in which the class is defined can be loaded, and that the class is not inaccessible due to its accessibility modifier (like an internal class). To keep the same instance you need to keep the instance alive. For per-user instances you can use the Page.Session variable. See my other reply for more details.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Customer Product-lifecycle Experience
Microsoft

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