Usage of Lambda Expression - C# Discussion Boards

Re: KeyEventArgs question: Get one of the arrow keys and space key at the same time

Dan Neely25-Jun-09 2:33

25-Jun-09 2:33

Because you get a separate event for each key pressed if you want to do custom combinations you need to set your own flags for each key of interest in the key down events and clear them in the key up events.

It is a truth universally acknowledged that a zombie in possession of brains must be in want of more brains.
-- Pride and Prejudice and Zombies

Re: KeyEventArgs question: Get one of the arrow keys and space key at the same time

Mc_Topaz25-Jun-09 6:48

Mc_Topaz

25-Jun-09 6:48

I figured out a solution based on your answer, thanks!

Printer Job status using PJL

koppewar25-Jun-09 0:51

koppewar

25-Jun-09 0:51

can anyone please tell me how to get the printer Job status using PJL command.I used the following command

sendString = String.Format("\x1B%-12345X@PJL \r\n @PJL JOB NAME = \"MyJob\" START = 1 \r\n PJL USTATUS JOB = ON \r\n @PJL INFO USTATUS \r\n @PJL ENTER LANGUAGE = PCL \r\n\x1B E . . . . PCL Job . . . . \x1B E\x1B%-12345X@PJL \r\n @PJL EOJ NAME = \"MyJob\" \r\n \x1B%-12345X\r\n");

Is this command appropriate?How to create JOB name or ID ?here I am giving my own name(MYJob)and job id shud b generated by printer or we have to give it while printing the document?Please help me to know the printer job status.

drag and drop file and/or add note to window form calendar

kyi kyi25-Jun-09 0:07

kyi kyi

25-Jun-09 0:07

hello all,

is there any idea to do that, pls? i only found out drag and drop file to listbox control.

thanks in advance,

kyi kyi

How to check if documents on shared folders are availiable?

Succodimele24-Jun-09 23:42

Succodimele

24-Jun-09 23:42

Hello

I have to build an application which checks if a document is still availiable on a specific path. This application is used on our intranet. Html sites are no problem but how can I check, if a file on a Share exits? e.g. \\Server01\share$\test.doc
It should be possible to differ if the share is unavailiable or if the user hasn't enough rights to access.
Are there any opensource solutions for this problem or with which method can i solve my problem?

thanks for your help!

best reagrds
succo

Re: How to check if documents on shared folders are availiable?

Sk9325-Jun-09 0:12

Sk93

25-Jun-09 0:12

Would System.IO.File.Exists() not do the job?

You could then catch any FileNotFound or AccessDenied exceptions?

Re: How to check if documents on shared folders are availiable?

Mycroft Holmes25-Jun-09 0:49

Mycroft Holmes

25-Jun-09 0:49

Look into storing and using the UNC path[^].

Never underestimate the power of human stupidity
RAH

Usage of Lambda Expression

HarishBhattbhatt24-Jun-09 23:41

HarishBhattbhatt

24-Jun-09 23:41

I am an experienced developer in c# and working on LOB application from last 7 Years, I have some issues in understanding usage of Lambda expression in programming.

As far as i understand it is useful in case of

1) Working with LINQ (Grouping, Select,Where etc..)
2) We can pass Lambda expression to any function as argument, so it can be used in place of delegate or anonymous function or normal function.
3)We can create generic lambda function which takes any datatype variable as argument and can return any datatype
e.g.
MyFirstLambdaFunc((val1,val2) => val1+val2)
public R MyFirstLambdaFunc<R,T>(Func<T,T,R> lambdaexpression,T x,T y)
{
R Result = lambdaexpression(x, y);
return Result;
}
4)Coding can be compact

Now the question is that

1) Are there any other advantages ?
2) When we pass lambda expression as function we can pass only single line operation?
3) Can anybody have some case study or some practical example document ?

Thanks in Advance

Harish Bhattbhatt

Re: Usage of Lambda Expression

led mike25-Jun-09 4:47

led mike

25-Jun-09 4:47

Greetings, welcome to CodeProject Beer | [beer]

About your interest in Lambda, Click Here[^]

Re: Usage of Lambda Expression

Niladri_Biswas25-Jun-09 6:03

Niladri_Biswas

25-Jun-09 6:03

Visit these sites

http://www.slideshare.net/udooz/let-us-learn-lambda-using-c-30-presentation[^]

Exploring Lambda Expression in C#[^]
Smile | :)

Niladri Biswas

Combobox control..........?? [modified]

Hum Dum24-Jun-09 23:09

Hum Dum

24-Jun-09 23:09

using vs2003.
Its a data entry application, having some fields and buttons.

In this, I am using combobox control, getting data from DB in DataTable obj dt, then setting the datasource property of Combobox to this dt.

there is New button, when user clicks on it, it simply clears all fields text, their DataBindings, for combox also i am using it as

cbBox.DataBinding.Clear();
cbBox.Text = "";

then there Save button which saves data to DB, on this Save click event i am checking data entered, like

if(cbBox.Text =="")//here it shows previous text if user do not enter any data
// after clicking New button (in debugging), but if user enter some data then that 
//entered data
{
// related code
}

But here is problem, after clicking new button, all fields got clear, cbBox text goes blank. But if user did not enter any data in cbBox then it retains the previous text(text before clicking New button)

a) why this? how to rectify.

b)Related to DataRow?
when we load some data from DB, we fill it in Datatable obj first.
then iterate thru all rows.

SQL = "Select * from Data where ID = 23";
execute this SQL against DB.
assume ID is primary key,
now only single row returned,

How to get this DataRow without filling it in Datatable?

regards,

modified on Thursday, June 25, 2009 7:35 AM

Re: Combobox control..........??

padmanabhan N24-Jun-09 23:31

padmanabhan N

24-Jun-09 23:31

Hum Dum wrote:
a) why this? how to rectify.

Ans: Check whether your have written your code in
if(!page.ispostback)
{
//check whether your code lies here....
}

Hum Dum wrote:
SQL = "Select name from Data where ID = 23";
execute this SQL against DB.
assume ID is primary key,
now only single row returned,

How to get this DataRow without filling it in Datatable?

string con = ConfigurationManager.AppSettings["connect"];
SqlConnection conn = new SqlConnection(con);
conn.Open();
SqlCommand cmd = new SqlCommand("select name from Data where ID=23", conn);
object obj = cmd.ExecuteScalar();
conn.Close();
string name = obj.ToString();

Padmanabhan
My Articles[^]

Re: Combobox control..........??

Hum Dum25-Jun-09 1:33

Hum Dum

25-Jun-09 1:33

padmanabhan N wrote:
if(!page.ispostback)

If i am not wrong then ispostback is for web application, mine is window......??

padmanabhan N wrote:
object obj = cmd.ExecuteScalar();

It will return only 1st most column, not the entire row?
But i want whole row content.

sorry for wrong query
I want to write

SQL = "Select * from Data where ID= 23"

Receive mail by C# code

khosnur24-Jun-09 22:45

khosnur

24-Jun-09 22:45

i am developing a software like microsoft outlook express.i done mail sending but i can not receive mail....

please help me its urgent

Re: Receive mail by C# code

stancrm24-Jun-09 23:00

stancrm

24-Jun-09 23:00

Retrieve Mail From a POP3 Server Using C#[^]

Re: Receive mail by C# code

khosnur6-Jul-09 23:45

khosnur

6-Jul-09 23:45

thanks a lot for reply i am dunning the source

Re: Receive mail by C# code

khosnur6-Jul-09 23:47

khosnur

6-Jul-09 23:47

But There is an error.

Error:Value cannot be null.
Parameter name: item

And its point to :Status.Items.Add(RdStrm.ReadLine());

Thank you

Image processing problem...

S K Y24-Jun-09 22:08

S K Y

24-Jun-09 22:08

how can i change the contrast of the image at the same time changing brightness. my brightness can change. its working fine i want to change the contrast at the same time....can i use this method too ???

Bitmap image = new Bitmap("d:\\14.jpg");
            Bitmap bm = new Bitmap(image, 350, 300);

            System.Drawing.Bitmap TempBitmap = bm;
            float FinalValue = 0.5f;
            System.Drawing.Bitmap NewBitmap = new System.Drawing.Bitmap(TempBitmap.Width, TempBitmap.Height);
            System.Drawing.Graphics NewGraphics = System.Drawing.Graphics.FromImage(NewBitmap);
            float[][] FloatColorMatrix ={
            new float[] {1, 0, 0, 0, 0},
            new float[] {0, 1, 0, 0, 0},
            new float[] {0, 0, 1, 0, 0},
            new float[] {0, 0, 0, 1, 0},
            new float[] {FinalValue, FinalValue, FinalValue, 1, 1}
        };

            System.Drawing.Imaging.ColorMatrix NewColorMatrix = new System.Drawing.Imaging.ColorMatrix(FloatColorMatrix);
            System.Drawing.Imaging.ImageAttributes Attributes = new System.Drawing.Imaging.ImageAttributes();
            Attributes.SetColorMatrix(NewColorMatrix);
            NewGraphics.DrawImage(TempBitmap, new System.Drawing.Rectangle(0, 0, TempBitmap.Width, TempBitmap.Height), 0, 0, TempBitmap.Width, TempBitmap.Height, System.Drawing.GraphicsUnit.Pixel, Attributes);
            Attributes.Dispose();
            NewGraphics.Dispose();

           picDecode.Image = NewBitmap;

A S E L A

Re: Image processing problem...

Christian Graus24-Jun-09 22:34

Christian Graus

24-Jun-09 22:34

You can add the contrast and brightness matrices, I guess, or you can apply one, then the other.

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

Re: Image processing problem...

S K Y24-Jun-09 23:28

S K Y

24-Jun-09 23:28

i could do it....but i got a big problem. as i told im doing a QR barcode reader by using webcam. my web cam pictures are too dark so i have to process image before i send it to decode. some times after process i code decode.but when the envirentmant change it couldn't decode. that mean when change brightness and contrast in enviranmetn i couldn't decode. is there any solution....may be auto brightness and contrast detect or some thing else....???

A S E L A

Re: Image processing problem...

Luc Pattyn24-Jun-09 23:57

Luc Pattyn

24-Jun-09 23:57

Hi,

I think you want a non-linear transformation, ideally something that maps all colors to either black or white. Maybe ImageAttributes.SetThreshold could help you out, provided you give it a good value, at best it would depend on the average brightness of your image,

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

How to retrive and save the attachments of the Mail from Pop3.

Nekkantidivya24-Jun-09 21:32

Nekkantidivya

24-Jun-09 21:32

Hi,

I am using Pop3 in my application. In this I am able to access the mails in the given Email Id. Now I have to download the files or images attached to the mails and save them in a temp folder.

If anyone gave idea to solve this please reply me.

Thanks in Advance.

Re: How to retrive and save the attachments of the Mail from Pop3.

Christian Graus24-Jun-09 21:46

Christian Graus

24-Jun-09 21:46

Are you using outlook ? Or have you written an actual POP3 server and written a mail program ?

importing table to another database

leone24-Jun-09 20:36

leone

24-Jun-09 20:36

I want to import some tables to a database in sql 2005. In a training video, I saw "all tasks" was used to realize this. despite using developer edition there is no all tasks. how can i use this all tasks function or how can i import tables with code.thanks

Re: importing table to another database

Mycroft Holmes24-Jun-09 20:45

Mycroft Holmes

24-Jun-09 20:45

you are asking a database ? in the C# forum.

In management studio, open the object explorer, right click on your database and there should be a Tasks menu item. Under here lies you tools.

Never underestimate the power of human stupidity
RAH

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