Re: Bindng and display problem - C# Discussion Boards

14-Jan-09 9:52

hi,
I have this problem which I have been trying to solve for some time but with no result Frown | :(

I have a table in sql server which consists of two columns: LastName and First name, and a result for a "select * from TestTable" is:

Doe John
NULL Mark

Then a I have a piece of code in my WinForms application:

string connString = "server=.;database=Test;Integrated Security=SSPI;";
            string sql = "select LastName, FirstName from TestTable";
            SqlConnection conn = new SqlConnection(connString);
            SqlDataAdapter da = new SqlDataAdapter(sql, conn);
            DataSet dataset1 = new DataSet();
            da.Fill(dataset1, "TestTable");
            DataTable dt = dataset1.Tables["TestTable"];

            listBox1.DataSource = dt;

            if (listBox1.DisplayMember.Length != 0)
            {
                listBox1.DisplayMember = "LastName";
            }
            else
            {
                listBox1.DisplayMember = "FirstName";
            }

            textBox1.DataBindings.Add("text", dt, "LastName");
            textBox2.DataBindings.Add("text", dt, "FirstName");

and it works fine, when there is a NULL value in teh LastName column, in the listBox the FirstName is diplayed. The binding works ok

Now when I alter the table and add another column (Company), the same sql query result looks like that:

Doe John NULL
Smith Mark NULL
NULL NULL Microsoft

Now when I make changes to the code to looke like this:

string connString = "server=.;database=Test;Integrated Security=SSPI;";
            string sql = "select LastName, FirstName, Company from TestTable";
            SqlConnection conn = new SqlConnection(connString);
            SqlDataAdapter da = new SqlDataAdapter(sql, conn);
            DataSet dataset1 = new DataSet();
            da.Fill(dataset1, "TestTable");
            DataTable dt = dataset1.Tables["TestTable"];

            listBox1.DataSource = dt;

            if (listBox1.DisplayMember.Length != 0)
            {
                listBox1.DisplayMember = "LastName";
            }
            else
            {
                listBox1.DisplayMember = "Company";
            }

            textBox1.DataBindings.Add("text", dt, "LastName");
            textBox2.DataBindings.Add("text", dt, "FirstName");
            textBox3.DataBindings.Add("text", dt, "Company");

in the listBox I only get the Microsoft entry. The other entries are there but are not visible by the LastName but blank, the binding still works.

http://img103.imageshack.us/my.php?image=50493721ap6.jpg
http://img397.imageshack.us/my.php?image=83000105po0.jpg

Can some help to solve this?

Wendelius14-Jan-09 11:14

14-Jan-09 11:14

Since you've binded the listBox1.DisplayMember to company name, it's quite obvious that the first two rows will show nothing since the company is null. What kind of result would you expect?

The need to optimize rises from a bad design.My articles[^]

wi5nia14-Jan-09 11:22

14-Jan-09 11:22

so what solution would suggest?

Wendelius14-Jan-09 11:28

14-Jan-09 11:28

That depends what do you want to show in the list box? Now you've defined to show only the company name. If there isn't any, nothing is shown.

For example, do you want to show a combined string in the list box? Something like:
Doe, John, Unknown
Smith, Mark, Unknown
Unknown, Unknown, Microsoft

The need to optimize rises from a bad design.My articles[^]

wi5nia14-Jan-09 11:31

14-Jan-09 11:31

no, I just want to show a list of LastNames from the table, and if there is a NULL value for the LastName column in a given row then show for that row the value from the column Company

Wendelius14-Jan-09 11:44

14-Jan-09 11:44

Okay, then you have at least two options. You can modify your SQL statement and create an additional column and bind to it, like (there may be typos in the examples):

string sql = "select LastName, FirstName, Company, <code>COALESCE(LastName, Company) AS ListData </code>"
             + "from TestTable";
SqlConnection conn = new SqlConnection(connString);
SqlDataAdapter da = new SqlDataAdapter(sql, conn);
DataSet dataset1 = new DataSet();
da.Fill(dataset1, "TestTable");
listBox1.DataSource = dataset1.Tables["TestTable"];
listBox1.DisplayMember = "<code>ListData</code>";

or after filling the dataset, you can create a computed column:

string sql = "select LastName, FirstName, Company "
             + "from TestTable";
SqlConnection conn = new SqlConnection(connString);
SqlDataAdapter da = new SqlDataAdapter(sql, conn);
DataSet dataset1 = new DataSet();
da.Fill(dataset1, "TestTable");
<code>dataset1.Tables["TestTable"].Columns.Add("ListData", 
                                         typeof(string), 
                                         "ISNULL(LastName,Company)");</code>
listBox1.DataSource = dataset1.Tables["TestTable"];
listBox1.DisplayMember = "ListData";

Hope it helps.

The need to optimize rises from a bad design.My articles[^]

wi5nia14-Jan-09 11:53

14-Jan-09 11:53

the second solution works like a charm Smile | :)

many thanks

Wendelius14-Jan-09 12:00

Telephone answering mechine service c#

14-Jan-09 12:00

You're welcome Smile | :)

The need to optimize rises from a bad design.My articles[^]

XDate in ZedGraph

Rayya14-Jan-09 9:23

Rayya

14-Jan-09 9:23

Hi,

I need the output of date time as DateTime format
"s" which means dd-MM-yyTHH:mm:ss using XDate of ZedGraph.

my code is s follow:
double x = (double)new XDate(yearData, monthData, dayData, hourData, minData, secData);

Then write AxisType.Date;

I am getting dd-MM-yy correctly, but HH:mm:ss as 00:00:00.

Can anyone please help to write a correct code to get the
required output?

Thanks.

Re: XDate in ZedGraph

EliottA14-Jan-09 12:44

EliottA

14-Jan-09 12:44

You won't find much help on third party controls here, you can consult their non-functioning wiki[^]

rikigr414-Jan-09 8:40

rikigr4

14-Jan-09 8:40

Hi All,

I am looking for code written in .NET that provides connection between application and telephone.
So that - the telephone will return a code according to input code that it get's from the user.

I'll be happy to get even a little help - if you know something that relate and can help me!!

Thanks. Wink | ;)

#realJSOP14-Jan-09 9:46

#realJSOP

14-Jan-09 9:46

TAPI, TAPI, He's your man!
If TAPI can't do it, no one can!

"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001

User 665814-Jan-09 10:09

User 6658

14-Jan-09 10:09

Wow, that was truly poetic Laugh | :laugh:

modified 12-Sep-18 21:01pm.

Rutvik Dave14-Jan-09 11:18

Rutvik Dave

14-Jan-09 11:18

as Jhon told you TAPI is the only way.

you can download c# wrappers here[^]

or you can use windows dll like this[^].

rikigr414-Jan-09 21:18

rikigr4

14-Jan-09 21:18

Thank you!
I would be happy to get more specipic help - about getting back answer from the telephone (and not dialinig to the talaphone from the computer).

Thanks again!

Hmmm | :|

yafa15-Jan-09 4:03

yafa

15-Jan-09 4:03

in the link u got, were the code here:

The code below is responsible for registering incoming calls so that they can be handled by our application. For that you need to select the line on which you want to receive calls and press the Register button.

 Collapse Copy Code
try
{
    registertoken[line]=tobj.RegisterCallNotifications(ia[line],
                 true,true,TapiConstants.TAPIMEDIATYPE_AUDIO,2);    
    MessageBox.Show("Registration token : "+ 
                 registertoken[line], 
                 "Registration Succeed for line "+line);
}
catch(Exception ein)
{
    MessageBox.Show("Failed to register on line "+line,"Registration for calls");
}

The class given below is to be added depending upon your TAPI event handling requirements. This is specially designed according to the requirements of the application.

please read the article!!