Updating a form from a class ( same instance) problem - C# Discussion Boards

Malcolm Smart3-Aug-07 3:49

Malcolm Smart

3-Aug-07 3:49

I was being sarcastic. Perhaps if you told us the viewer we could help. Also, what has this to do with C#?

"More functions should disregard input values and just return 12. It would make life easier." - comment posted on WTF

hamid_m3-Aug-07 3:54

hamid_m

3-Aug-07 3:54

i guess there was any properties in xmldocument or other xml classes that close all nodes (maybe you called them Tag) of an xml file when it open by IE or other xml viewers

PIEBALDconsult4-Aug-07 4:34

PIEBALDconsult

4-Aug-07 4:34

It's not a function of the document, it's a function of the viewer; for instance a TreeView has a CollapseAll() method.

Asynchronous UDPClient BeginReceive Method

hamid_m4-Aug-07 5:16

hamid_m

4-Aug-07 5:16

at last i fund that it did by xslt file Wink | ;)

martin_hughes2-Aug-07 23:59

martin_hughes

2-Aug-07 23:59

Hey all,

I'm having trouble with the Asynchronous UDPClient.BeginReceive() method. I've finally gotten the (extremely poor) example in the MSDN docs working, however as soon as it receives any data the application quits, when ideally I'd want it to continue listening to the port.

To get around this, I simply call the method containing the call to BeginListen() again from the callback, but I'm having serious doubts about this as a preferred method of doing things, given that this method (and from MSDN) simply blocks in a while loop:

// Do some work while we wait for a message. For this example,
// we'll just sleep
while (!messageReceived)
{
  Thread.Sleep(100);
}

and without this "Do some work" business the application just quits again. Now this could actually be quite useful, as the reason I'm looking at this BeginReceieve stuff is so that I can terminate the listener as and when I want to, which seems a lot more tricky when using blocking port access.

So after all that rambling, is this the way it should be done, or have I hacked myself into a tight spot?

"It was the day before today.... I remember it like it was yesterday."

-Moleman

Re: Asynchronous UDPClient BeginReceive Method

Guffa3-Aug-07 1:52

Guffa

3-Aug-07 1:52

The example is not quite up to the normal standard for examples in MSDN (with the one letter variable names for one), but it's still adequate to show how the method is to be used.

Examples in MSDN is not on the "for dummies" level, they are just short examples to show the code in some kind of context. If you need more than that, you should buy a book about it.

martin_hughes wrote:
To get around this, I simply call the method containing the call to BeginListen() again from the callback

Yes, that's what you normally would do. Alternatively, you could call the method from your main program after processing the data.

martin_hughes wrote:
but I'm having serious doubts about this as a preferred method of doing things, given that this method (and from MSDN) simply blocks in a while loop

As the comment in the code says, it's just an example. Normally your program would just continue with what it's normally doing, usually just go back to the message pump and wait for something to happen.

---
single minded; short sighted; long gone;

Re: Asynchronous UDPClient BeginReceive Method

martin_hughes3-Aug-07 2:38

martin_hughes

3-Aug-07 2:38

Well, I still think the example is poor - and definitely not up to scratch. But thanks for the advice anyway Smile | :)

"It was the day before today.... I remember it like it was yesterday."

-Moleman

Updating a form from a class ( same instance) problem

Hardboiled862-Aug-07 23:58

Hardboiled86

2-Aug-07 23:58

Been trying find a way to update a form ( same instance) directly from a class.My example below compiles but the form result leaves the textbox blank.
using the Form1 myform = new Form1 thing works but again leaves the form blank.

Can anyone help? I'm new to this so go easy on me.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace test1
{
public partial class Form1 : Form
{
public string strStringVarible;

public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{

}

private void button1_Click(object sender, EventArgs e)
{
classtest1 clstest = new classtest1();
clstest.external_class();

}

public void accessor_method()
{
this.textBox1.Text = strStringVarible;
this.textBox1.Refresh();
}

private void textBox1_TextChanged(object sender, EventArgs e)
{

}

}
}

________________________________________________________

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms.Design;
using System.Data;

namespace test1
{
class classtest1 : Form1
{

public void external_class()
{
this.strStringVarible = "test123";
this.accessor_method();

}

}
}

I'm new so go easy on me please

Re: Updating a form from a class ( same instance) problem

Martin#3-Aug-07 1:34

Martin#

3-Aug-07 1:34

Hello,

What you did is:
You have a Form named "Form1" (which derives from System.Windows.Forms.Form).
Than you have a Form named "classtest" (which derives from your Form1).

Hardboiled86 wrote:
private void button1_Click(object sender, EventArgs e)
{
classtest1 clstest = new classtest1();
clstest.external_class();

}

At the button Click, you instanciate a new Form (classtest1), which means that now two Forms are in memory (one that you see, and the new second one).
You call the method "external_class" from your second Form, which calls "accessor_method" also from your second Form.

So it should be clear that your first Form, which is visible will not change.

Look at this excellent Article from Colin Angus Mackay[^]

Hope it helps!

All the best,

Martin

Re: Updating a form from a class ( same instance) problem

Chintan.Desai3-Aug-07 2:57

Chintan.Desai

3-Aug-07 2:57

NEVER put such code in forum,only put the code wich u feel having a problem.No one has time to see this kind of stupid stuffs.

Regards
Chintan
www.visharadsoft.com
(Nothing is so purify as KNOWLEDGE)

AVI frames to JPG or BMP conversion using C#

sriathma2-Aug-07 23:46

sriathma

2-Aug-07 23:46

Hi I have to convert the
AVI frames to JPG or BMP
format. Kindly send the C# code
for the same.
Thanking you
Sridharan

open file which can see inside of it

nhathoang2-Aug-07 23:24

nhathoang

2-Aug-07 23:24

when we want open a file,we have to double click on the file,but Right now,i want open it by command,What must I do?,(note: open file which can see inside of it)

Christian Graus2-Aug-07 23:27

Christian Graus

2-Aug-07 23:27

File.GetAllText ? Hard to know, your question isn't really laid out in a way that makes much sense.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Manoj Kumar Rai2-Aug-07 23:53

Manoj Kumar Rai

2-Aug-07 23:53

Use StreamReader object to read the content of the file and display it in a window. Also, please make sure that your file may not only contain text data but it can contain picture etc. Hence, if you want to see the real world inside the file you should reading it in binary format and display the records.

Manoj
Never Gives up

nhathoang3-Aug-07 0:02

nhathoang

3-Aug-07 0:02

thanks you,I am sorry because I don't display obvious my ideal
After that,I will display my question
when we double click a file,the window of file will display,and we can see the tittle of it(EX: file.txt)
If we use command of C#,what will we do to see the window of file.txt opended ?

Create a telephone directory

Chintan.Desai3-Aug-07 2:58

Chintan.Desai

3-Aug-07 2:58

just use Process class.Inside it there one method which takes input as file name and opens it.

Regards
Chintan
www.visharadsoft.com
(Nothing is so purify as KNOWLEDGE)

sgeorgije2-Aug-07 22:49

sgeorgije

2-Aug-07 22:49

I want to represent telephone directory in this way.
Certainly, anybody may have more phones and each of them must be visible.

It is all dispose in more columns, that economically use working surface.

Table:
TelDirectory (ID,Name,Tel)
PK(ID) - primary key

How to show data like this:

Name1.....Name4
------.....------
Tel11......Tel41
Tel12

Name2
------
Tel21
Tel22
Tel23

Name3
------
Tel31

...

Thanks for any help.

Christian Graus2-Aug-07 23:06

Christian Graus

2-Aug-07 23:06

where are you showing it ? If in a web app, a repeater is your best option.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

sgeorgije2-Aug-07 23:12

sgeorgije

2-Aug-07 23:12

It's a win app.

Christian Graus2-Aug-07 23:21

Christian Graus

2-Aug-07 23:21

Then it's up to you to render the results any way you like. No built in control will give the layout you're wanting, however.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Manoj Kumar Rai2-Aug-07 23:15

Manoj Kumar Rai

2-Aug-07 23:15

First of all, the ID cannot be a Primary Key as it will not be unique, since anybody can have more than 1 phones.

You can get the list sorted on ID/name of the customer. Once it is sorted it will be esily printed.

Manoj
Never Gives up

Colin Angus Mackay2-Aug-07 23:45

Colin Angus Mackay

2-Aug-07 23:45

Manoj Kumar Rai wrote:
First of all, the ID cannot be a Primary Key as it will not be unique, since anybody can have more than 1 phones.

How does that make ID not unique

1 Colin Mackay 0123 456 7890
2 Colin Mackay 0321 654 0987

Looks fine to me - What did you think was wrong with it?

Upcoming events:
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"I wouldn't say boo to a goose. I'm not a coward, I just realise that it would be largely pointless."

My website

Manoj Kumar Rai3-Aug-07 0:00

Manoj Kumar Rai

3-Aug-07 0:00

Ahhh, Ok. Its record ID and not the ID of the person where I thought wrongly. But in either case for the problem we had to print this Unique key do not have any role to play. We have to sort the list on the basis of the Name and get the values printed.

Manoj
Never Gives up

Malcolm Smart2-Aug-07 23:40

Malcolm Smart

2-Aug-07 23:40

You posted this exact same question a few days ago. What have you tried since then? Even writing some long, slow, even poor code, to get the job done will give you a starting point. Then post snippets of that code, and the people here will help optimise it.

"More functions should disregard input values and just return 12. It would make life easier." - comment posted on WTF