Re: Threads and Controls - C# Discussion Boards

Re: getting enum integer ?

Member 26118817-Dec-03 0:19

Member 261188

17-Dec-03 0:19

Try this:

public enum OutputType : int
{
    None = 0,
    TIFF = 1,
    JPEG = 2,
    BMP = 3
}
[...]
int num = (int)OutputType.JPEG;

You can also use uint, long, char, ulong, byte, ubyte, decimal, double, float, and maybe even string. But I suggest int, since it doesn't put such a heavy load on the processor.

- Daniël Pelsmaeker

One fool can ask more questions than all the wise men can answer.

Re: getting enum integer ?

Heath Stewart17-Dec-03 3:39

Heath Stewart

17-Dec-03 3:39

Actually, enum values automatically derive from int. And you can't use string (this is well documented in the Enum Type documentation).

Besides, this isn't necessary. The cast is the important thing, and so long as you don't overflow or anything like that. For instance, in your example, all the numbers are small and possitive so you could still cast to a short, long or whatever.

-----BEGIN GEEK CODE BLOCK-----
Version: 3.21
GCS/G/MU d- s: a- C++++ UL@ P++(+++) L+(--) E--- W+++ N++ o+ K? w++++ O- M(+) V? PS-- PE Y++ PGP++ t++@ 5 X+++ R+@ tv+ b(-)>b++ DI++++ D+ G e++>+++ h---* r+++ y+++
-----END GEEK CODE BLOCK-----

Saving windows forms created at runtime

kvimal16-Dec-03 12:49

kvimal

16-Dec-03 12:49

Hi All,

At runtime,I have created an instance for windows form and added controls in it.I want to save that form using Save dialog box.I need both resx and cs files.Is there any way to save the form created at runtime.

Thanks
Vimal

Re: Saving windows forms created at runtime

Colin Angus Mackay16-Dec-03 13:01

Colin Angus Mackay

16-Dec-03 13:01

If you can create the form at run time then you can recreate it at runtime in the next session. Save to the file the data needed to create the form in the first instance and then when you load the file the data in it will describe the form to your program again. It can then recreate the form.

--Colin Mackay--

"In the confrontation between the stream and the rock, the stream always wins - not through strength but perseverance." (H. Jackson Brown)

Enumerators in .NET: See how to customise foreach loops with C#

Re: Saving windows forms created at runtime

Nigel Savidge17-Dec-03 4:30

Nigel Savidge

17-Dec-03 4:30

To do it properly you need to use:

using System.CodeDom;
using System.CodeDom.Compiler;

you can use the methods in these classes to serialize your form and generate .cs and .resx files for it and also a .dll file.

It is not easy.

Threads and Controls

Guinness4Strength16-Dec-03 11:59

Guinness4Strength

16-Dec-03 11:59

I have a application that neds to have a listening socket thread. I've created the worker thread but I'm not sure how to access my Windows Form controls from with in the thread. I'l like to update a TextBox with text from within the worker thread.

Re: Threads and Controls

Mike Ellison16-Dec-03 14:15

Mike Ellison

16-Dec-03 14:15

Hi. This article on DevX may have what you're looking for (page 3 in particular discusses accessing Windows Form controls from launched threads)

http://www.devx.com/dotnet/Article/11358/0/page/1[^]

Re: Threads and Controls

Heath Stewart17-Dec-03 3:35

Heath Stewart

17-Dec-03 3:35

And just to avoid any possible problems, pay attention to how you use Control.Invoke from the worker thread in that article Mike gave you. This is a common mistake. Updating the UI from thread besides the main thread has "undefined" behavior. Sometimes it works, sometimes it doesn't, and sometimes it screws up your message pump (or, loop) so that some messages aren't handled correctly! Eek! | :eek:

Mdi problemo

datainjector16-Dec-03 10:09

datainjector

16-Dec-03 10:09

Okay here is what the problemo is ..

I am using MDI ... so i have this modal dialog box which opens up when the user clicks on a menuitem ... The person needs to enter some info into the dialog and click okay after that the values are passed to another form that is a MDI Child to the main form ... The problem is when the user clicks the close button the programm crashes ... I know why it does that because on the Okay button i inserted the code in the closing event so when the person closes the modal dialog with out filling anyhting in it .. it crashes which makes sence ...

I cant find a way to get around this problem ... The programm is a video lib managment system ... the modal dialog takes in the users code and opens the renting form ... Which is the mdi child ..

let me post the code it might help

<br />
CustomerCodeDialog cust == new CustomerCodeDialog();<br />
cd.ShowDialog();<br />
<br />
string customer_code = cust.getCustomerCode(); //which is a function that retrives the customer code from the text box<br />
string custoerm_name = cust.getCustomerName();<br />
<br />
issueWindow issue = new isuueWindow();<br />
issueWindow.MdiParent = this;<br />
issueWindow.Show();<br />

And please i cant find a good tutorials on MDI form for C# on codeProject or any other web site .. any links would help me alot...

Sorry my wnglish isnt that great ...

Thanks
DaIn

Re: Mdi problemo

Heath Stewart17-Dec-03 3:29

Heath Stewart

17-Dec-03 3:29

If the inputs are validating, crashing the problem makes sense?! WTF | :WTF:

You need to validate your inputs and gracefully warn the user or exit, depending on the circumstances (exiting, like in the case of 3 invalid password attempts or something). Crashing your program is not acceptable for clients!

Besides, never trust user input. Always validate input, even if it's just checking to see if input was provided. You should also put such commands in try-catch blocks so execeptions are caught and handled correctly.

One more thing, when using modal dialogs, you need to dispose them when you're done. So, after you get done grabbing values form your cust variable, call cust.Dispose(). Otherwise, the memory for the modal dialog (actually, this has to do with native handles used to display the modal dialog) won't be freed. This also helps keeps the memory footprint of your app down.

As far as MDI tutorials, I can't recommend any, but you should read the .NET SDK Documentation for the MDI-related methods and properties, such as Form.MdiChildren, Form.MdiParent, Menu.MergeMenu, and the like. It's not great, but it might give you a little more insight to some specific questions you might have. Otherwise, just ask the forum! Smile | :)

Re: Mdi problemo

Heath Stewart17-Dec-03 3:32

Heath Stewart

17-Dec-03 3:32

Oh, and as far as validating inputs, it's common practice to not let the user close the dialog until they've either canceled the dialog or enter the valid values. You should also get a DialogResult back from the ShowDialog call so you know what the user did:

DialogResult result = cust.ShowDialog();
if (result != DialogResult.OK) return;

Or something like that. Then, in your form, make sure your OK and Cancel buttons have the right DialogResult property set (OK or Cancel), and that your form specifies the Form.AcceptButton and Form.CancelButton.

Re: Mdi problemo

datainjector17-Dec-03 10:15

datainjector

17-Dec-03 10:15

Thanks alot for the help Smile | :)

Remote Debugging

mikemilano16-Dec-03 9:13

mikemilano

16-Dec-03 9:13

i need to develop on a network server here at work, but we can't get it setup right.

according to microsoft, you either need to be logged into the network as the same user as the asp.net process runs under, ... or ... logged in as an administrator of the box.

our admin says he can't set me up as admin, and i can not login as the asp.net process.

I am setup in the 'Debug' group on the server, but I still get permission errors.

anyone know any other way i can debug remotely with asp.net ?

Re: Remote Debugging

Heath Stewart17-Dec-03 3:23

Heath Stewart

17-Dec-03 3:23

It doesn't really matter which group you're in, so long as you have the debugging privilege (and just because there is a group named 'Debug', it doesn't necessarily mean these privileges have been granted). The priviliges should be configured in the Security snap-in for the computer, DC, or domain. The admin should also make sure that the Local Security Policy for the computer has the privileges assigned. Since domain privileges take precedence over local ones, using the Local Security Policy shows you whether a user or group really will have those privileges.

Second, don't forget to enable debugging in the Web.config file.

Finally, make sure the debugging tools are actually installed on the server. If you install the .NET Framework SDK on the server, I believe this is enough. In the VS.NET setup, there are some additional tools you can install remotely, but I believe these are only for DCOM debugging.

context menu with drag/drop and right click

mikelb16-Dec-03 4:37

mikelb

16-Dec-03 4:37

I'm looking for menu code that will allow the user to drag/drop menu items to move them where they want and allow detection of a right click on a menu item.

Any pointers would be appreciated.

interfaces and GUIDS

Jinwah16-Dec-03 4:27

Jinwah

16-Dec-03 4:27

Can anyone help?

I want to code an interface and assign a GUID to it.

public interface IMyInterface
{
}

On the web I found articles that say I should put the interfaces GUID above the interface declaration. But I get an error message saying GUID is not recognised. My using clause has System. So how can I do this?

The reason is in Delphi my objects support interfaces and then by zooming thru a list of objects I can ask if the object supports the interface and if so talk to the object thru that interface.

I have had a good look thru my books and internet articles but cannot find any really good info.

If there is a new way to do this I would also be interested.

Thanks

Luke

Re: interfaces and GUIDS

Heath Stewart16-Dec-03 5:11

Heath Stewart

16-Dec-03 5:11

Yes, you do use the GuidAttribute but you must use the right namespace: System.Runtime.InteropServices. You can either include it toward the top with the using statement, or prefix your GuidAttribute (or any class for that matter) with the proper namespace. You must also be referencing the assembly in which the Type contains. I'm only mentioning this so you understand. The System.Runtime.InteropServices.GuidAttribute Type is in the mscorlib.dll assembly, so it is automatically referenced by the compiler (unless it's told otherwise, which is only possible with the command-line compiler).

Re: interfaces and GUIDS

Jinwah16-Dec-03 5:34

Jinwah

16-Dec-03 5:34

is that above the interface declaration

System.Runtime.InteropServices.GuidAttribute["....."]
public interface IMyinterface
{
}

And how can I ask an object if it supports the interface so that I can talk to it soley thru that interface (this is how I would have done it in Delphi)

Cheers

Luke

Re: interfaces and GUIDS

Heath Stewart16-Dec-03 5:45

Heath Stewart

16-Dec-03 5:45

No offense meant, but you should probably read the C# specification. Attributes are like so (fully-qualified example):

[System.Runtime.InteropServices.Guid("363EBCCC-5E9A-4e14-8A5D-F0DA44E69EF9")]
public interface IMyInterface
{
{

In C# (and some other languages, but you have to read their specs to find out), you can drop the "Attribute" at the end of attributes. If you want to use properties that aren't in the constructor parameters, fill all the necessary params then use PropertyName=Value, like so:

[MadeUpAttribute("somestring", SomeParam="SomeValue")]
public class SomeClass
{
}

Re: interfaces and GUIDS

Jinwah16-Dec-03 22:04

Jinwah

16-Dec-03 22:04

No offence taken. I have brought 2 very good reference texts for C# / .NET. My problem is that I professionally program in Delphi. So I know what I want to do but I haven't yet got used to framing the question I want to ask in C# terms to get the answer. But moving to C# has been very easy due to the similar class libraries so I have a head start on my fellow C++ m8s.

Thanks for your help tho.

Re: interfaces and GUIDS

Heath Stewart17-Dec-03 3:13

Heath Stewart

17-Dec-03 3:13

My comment wasn't in reference to how you "framed" your question, but rather your syntax. Attributes in C# are enclused in square brackets ([ and ]) and you tried using them for your constructor params, which are always parens (( and )). This is just a simple matter of syntax. While it's true that the syntax (i.e., language) you use to write your code for .NET isn't really so important (knowing how to use and extend the base class library, and how to make your own libraries and applications is more important), you still need to know the syntax of the language you've choosen. I was just pointing out that you should read over the C# language specifications to know exactly what the syntax is - you might even learn a few tricks that aren't always discussed in books (like using the using statement to automatically dispose IDisposable implementations, or to use the same statement to creat a Type alias (especially handy when you have Type collisions, i.e. two different Types with the same name that belong to two or more namespaces you've imported).

Re: interfaces and GUIDS

Member 26118817-Dec-03 6:02

Member 261188

17-Dec-03 6:02

Im my opinion, a good example of the uses of attributes is when it comes to describing properties for the property explorer in Visual Studio.net.

using System;
using System.ComponentModel;

namespace Examples
{
    public class ExampleControl : UserControl
    {
        private IndentStyle m_eExampleProperty = IndentStyle.Smart;
        [
        Category("Design"),
        Description("Gets/sets an example value."),
        DefaultValue(IndentStyle.Smart),
        Browsable(true)
        ]
        public IndentStyle ExampleProperty
        {
            get
            {
                return m_eExampleProperty;
            }
            set
            {
                m_eExampleProperty = value;
            }
        }
    }
}

This would produce this kind of output:

If you want to try this out, just cut-and-paste the code into a source file, and create an instance of the control on the designer form.

- Daniël Pelsmaeker

Microsoft is to quality software what McDonalds is to gourmet cooking

Setting Up Computer to run IIS/ASP.NETwith C#

Larry J. Siddens16-Dec-03 4:22

Larry J. Siddens

16-Dec-03 4:22

I need some help getting my puter setup to run ASP.NET apps. I have IIS installed and the Web Publishing is running. I have also shared the folder where the app is. I keep getting an error:

"http://localhost/<name> HTTP 500 internal error!

Real informative! Can anyone give me some suggestions on what needs to be running?

Thanks

Larry J. Siddens

Re: Setting Up Computer to run IIS/ASP.NETwith C#

Heath Stewart16-Dec-03 5:08

Heath Stewart

16-Dec-03 5:08

Well, for one, you need to install ASP.NET with the .NET Framework. If you're having problems, you should run "aspnet_regiis.exe /i". Read more about aspnet_regiis.exe in the .NET Framework SDK documentation. There's some other options.

Another possibility is that your ASP.NET page - or your IIS extension mappings - have an error and are causing a server error. Without knowing more, it's hard to say. The error says it all: server error. Millions of things could be wrong.

Re: Setting Up Computer to run IIS/ASP.NETwith C#

Larry J. Siddens16-Dec-03 7:03

Larry J. Siddens

16-Dec-03 7:03

Hey, new message!

Unable to open Web project "project name". The file path <path> does not correspond to URL 'http://Localhost:/<project name>'. the two need to map to the same server location. HTTP Error 403: Access.

I get this when I open a project under C#!

Larry J. Siddens

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