C# Discussion Boards - CodeProject

8-Oct-07 4:55

You have to link the text box on the SelectedIndexChanged event of the combobox. There you should create specify the datasource for the textbox/label or whatever you use.

Hope it helps

There are 10 kinds of people: those who understand binary and those who don't

Re: Link Display Problem

MumbleB8-Oct-07 8:45

MumbleB

8-Oct-07 8:45

Thanks mate but maybe I am a little stupid but how? Sorry bout this.

Float Data Type

Imran Adam8-Oct-07 4:44

Imran Adam

8-Oct-07 4:44

ok i know this must be a silly question, but im new to c# and still learning.....

I am trying to display a float value to the console, but it only appears as a whole number. (I am trying to display the average of an array of numbers)

This is what i have;

float result = Total/NumberArray.Length; //to store avg value in flaot var
.
.
Console.WriteLine("Average " + result); //to show value on screen

Where Total is The sum of the numbers
NumberArray.Lenghth is lenghth of array

For example (20+20+10)/3 = 16.66666
What i see on the screen is 16

Help would be appreciated???

Cheers

Andrei Ungureanu8-Oct-07 4:49

8-Oct-07 4:49

Try this:

float result = (Total*1.0)/(NumberArray.Length*1.0);
.
.
Console.WriteLine("Average " + result);

If you divide 2 integers, even if you store the result in a float, the result is also integer, so try a small "cast"

There are 10 kinds of people: those who understand binary and those who don't

Dan Neely8-Oct-07 4:53

Dan Neely

8-Oct-07 4:53

a real cast is more efficient than your kludge. In any event you don't need to cast both numbers, just the one.

--
If you view money as inherently evil, I view it as my duty to assist in making you more virtuous.

Imran Adam8-Oct-07 4:57

Imran Adam

8-Oct-07 4:57

Thanks Andrei

How silly of me, i should of thought of type 'casting';)

this also works

float result = ((float)Total/NumberArray.Length);

Cheers

Andrei Ungureanu8-Oct-07 4:58

8-Oct-07 4:58

I know that casting also works, it was just another way of doing things Wink | ;)

There are 10 kinds of people: those who understand binary and those who don't

Dan Neely8-Oct-07 4:52

Dan Neely

8-Oct-07 4:52

I assume total is also an integer. IF so what's happening is that you're doing integer division, getting an integer result and then converting the int into a float.

What you need to do is cast one of the ints into a float before doing the division.

float result = (float)Total/NumberArray.Length;

Depending on order of operations you might need a second parenthesis to get the desired result.

float result = ((float)Total)/NumberArray.Length;

--
If you view money as inherently evil, I view it as my duty to assist in making you more virtuous.

Imran Adam8-Oct-07 4:58

Imran Adam

8-Oct-07 4:58

Yes thanks Dan Wink | ;)

Cheers

Anthony Mushrow8-Oct-07 5:06

Anthony Mushrow

8-Oct-07 5:06

Also, you may want to limit the number of decimal places shown, you can do that like this:

float fTest = 123.456789f;

string sTest = fTest.ToString("N3");

that would put it at 3 decimal places, N5 would show 5 decimal places and so on. Just thought you might like to know. Incase you didn't already.

My current favourite word is: Waffle

Cheese is still good though.

check if record exist in a database C# sql 2005

Pete O'Hanlon8-Oct-07 5:10

Pete O'Hanlon

8-Oct-07 5:10

Ooh - you're hitting an issue that regularly causes confusion and gets a lot of people hot under the collar about .NET. Basically, the issue is that the Total value is an integer. You need to cast the result to a float so this would become float result = (float)Total/NumberArray.Length;

Deja View - the feeling that you've seen this post before.

Gazide8-Oct-07 4:02

Gazide

8-Oct-07 4:02

Hello

I am kind of new to C#(2.0) and MS SQL 2005, I am battling to write code (windows app C#), that can check Sql table to see if a record already exist. I have a table in sql called [Resources] with a PK called(Personnelno), i am trying to write a stored proc that can check if a [personnelno] exist in the table. if it exist it shouldn't save the record, else save it.

The application is three tiered [DAL, Business object and Presentation], can anyone please show me how do i call this stored proc through this layers until to the presentation layer. i'm trying to show messagebox to let user know that the record already exist, so he or she can change it.
Thanks.

N. Gazide

Re: check if record exist in a database C# sql 2005

Andrei Ungureanu8-Oct-07 4:18

Re: check if record exist in a database C# sql 2005

8-Oct-07 4:18

Here is a small example to get you started. You can find more in System.Data.SqlClient namespace.

SqlConnection connection = new SqlConnection(connectionstring);
SqlCommand command = new SqlCommand(connection);
command.CommandType = CommandType.StoredProcedure;
command.CommandText = "ProcedureName";
SqlDataReader reader = command.ExecuteReader();

There are 10 kinds of people: those who understand binary and those who don't

ffowler8-Oct-07 5:49

ffowler

8-Oct-07 5:49

Additional to what Andrei submitted, you could check the return value from your stored procedure to see if the record exists. For example in your SP you could use:

IF EXISTS(Select Pinfo from
Where Pinfo = @info)Begin
RETURN 2
END
Else
BEGIN
<insert stuff="" here.......="">
END

If the return value is 2 then you know the record exists. Check out SQLParameters and ParameterDirection.ReturnValue for help.

HTH

F

Online Verification

Nokoff8-Oct-07 4:00

Nokoff

8-Oct-07 4:00

Hi there, I am currently in negotiations with a customer that wishes to purchase an application that I have developed for him in C#. My dilemma is that although I trust him I wish to be able to give him a working copy of the application knowing that he will not just be able to 'steal' it. Seeing as the application needs to be online to function in any case I thought that maybe I could incorporate a request into the application to verify whether or not it should run so that I can disable it if something smells funny rendering the application useless.

I have attempted to use a HttpWebRequest request to try and retrieve the string of a file on my website and authenticate it that way but it seems that it caches somewhere or something but it takes a very long time for it to take effect. Here is my current Verification method:

private bool allowedToRun()<br />
        {<br />
            // used to build entire input<br />
            StringBuilder sb = new StringBuilder();<br />
<br />
            // used on each read operation<br />
            byte[] buf = new byte[8192];<br />
<br />
            // prepare the web page we will be asking for<br />
            HttpWebRequest request = (HttpWebRequest)<br />
                WebRequest.Create("urlOfMyWebPage.html");<br />
<br />
            // execute the request<br />
            HttpWebResponse response = (HttpWebResponse)<br />
                request.GetResponse();<br />
<br />
            // we will read data via the response stream<br />
            Stream resStream = response.GetResponseStream();<br />
<br />
            string tempString = null;<br />
            int count = 0;<br />
<br />
            do<br />
            {<br />
                // fill the buffer with data<br />
                count = resStream.Read(buf, 0, buf.Length);<br />
<br />
                // make sure we read some data<br />
                if (count != 0)<br />
                {<br />
                    // translate from bytes to ASCII text<br />
                    tempString = Encoding.ASCII.GetString(buf, 0, count);<br />
<br />
                    // continue building the string<br />
                    sb.Append(tempString);<br />
                }<br />
            }<br />
            while (count > 0); // any more data to read?<br />
<br />
            // print out page source<br />
            MessageBox.Show("Allowed to run: " + sb.ToString());<br />
            return Convert.ToBoolean(sb.ToString());<br />
<br />
        }

Ideas?

il_masacratore8-Oct-07 4:16

il_masacratore

8-Oct-07 4:16

Have you thinked to use a webservice?

Visit my blog at http://dotnetforeveryone.blogspot.com/

Nokoff8-Oct-07 4:34

Nokoff

8-Oct-07 4:34

I'm not familiar with the webservice. Could you point me to a tutorial or sample application?

Andrei Ungureanu8-Oct-07 4:42

8-Oct-07 4:42

Try Google first and also try this article. And search codeproject for articles and google also when you receive an idea because you'll find everything you'll need.

There are 10 kinds of people: those who understand binary and those who don't

Nokoff8-Oct-07 4:54

Nokoff

8-Oct-07 4:54

I have consulted google and I've reviewed the projects on the site but unfortunately I'm not sure how to integrate those tutorials into what I'm trying to do here. I basically need to call a function and return it's value to my program. And I also need to be able to modify it's value.

Andrei Ungureanu8-Oct-07 5:02

Re: DataGridView Selections

8-Oct-07 5:02

Nokoff wrote:
I basically need to call a function and return it's value to my program. And I also need to be able to modify it's value.

You can write a webservice with 2 methods. A GetValue method and a SetValue method. You will be able to call these functions in your app to read a value and set a value.
It's just an idea.

Hope it helps.

There are 10 kinds of people: those who understand binary and those who don't

DataGridView Selections

ffowler8-Oct-07 3:59

ffowler

8-Oct-07 3:59

Hello All,

I have a datagrid view on a windows form that I have working pretty well. I did not have the "MultiSelect" set to true so naturally the user was only able to make one row selection at a time and this worked fine.
Now the users have come up with a solution to trim their work time by being able to select multiple rows and have the processing done on the rows selected.
Here is my problem. I know how to retrieve the value in the first cell of the selected row but how do I go about selecting the values from the first cell in the subsequent rows that have been selected. I thought of using a 'for' statement but I am not sure how to move to the next row to retrieve the value of the next cell.

Thank you in advance for any help provided. Confused | :confused:

Anthony Mushrow8-Oct-07 4:05

Anthony Mushrow

8-Oct-07 4:05

In general, things with a SelectedItems property can just be used like an array. So to get the first selected row, you just use

SelctedItems[0]

and for the second

SelectedItems[1]

etc. Im not sure if its called SelectedItems in a datagrid but it should work the same. I could be mistaken. If you've not got an answer by the time i get home, i'll check it out.

My current favourite word is: Waffle

Cheese is still good though.

Re: DataGridView Selections

Andrei Ungureanu8-Oct-07 4:07