Re: Generics question - C# Discussion Boards

22-Nov-07 21:58

Split the dataset into 2 datasets or datatables that contain fields from only one table, and then use these to update the database.

I will use Google before asking dumb questions

Re: updating database

Andrei Ungureanu22-Nov-07 22:07

22-Nov-07 22:07

I won't write the code for you...try to do something and if you get stuck...post a question with your problem.

I will use Google before asking dumb questions

Generics question

calendarw22-Nov-07 21:04

22-Nov-07 21:04

Hi,

I got a problem that I would like to return a generic object in a non-generic object, what can I do?
I searched a lot of page but it's talking about how to use or implement a generic class, but if I want to implement a normal class and return a generic object according parameter, what can I do?

e.g.

class DaoFactory
{
Dao<T, IdT> GetDao(Type t)
{
//something like this.
//how to implement?
}
}

Thanks

Jr. P
calendarw

Andrei Ungureanu22-Nov-07 21:15

22-Nov-07 21:15

How about this one?

/// <summary>
/// Convert an ArrayList from a derived type to the base type
/// </summary>
/// <typeparam name="S">Derived type</typeparam>
/// <typeparam name="D">Base type</typeparam>
/// <param name="list">The ArrayList</param>
/// <returns>An ArrayList containing elements converted to the base type</returns>
public static List<D> Transform<S, D>(List<S> list) where S : D
{
List<D> lst = new List<D>();
foreach (S element in list)
lst.Add(element);
return lst;
}

I will use Google before asking dumb questions

calendarw22-Nov-07 21:39

22-Nov-07 21:39

Thank you.

I changed to this:
public static List<D> Transform<D>(System.Collections.IList list)
{
List<D> lst = new List<D>();
foreach (D element in list)
lst.Add(element);
return lst;
}

Actually, I tried to search using google but I don't know what keyword should be used for this case.

Andrei Ungureanu22-Nov-07 21:45

22-Nov-07 21:45

How about [this]

Hope it helps.

I will use Google before asking dumb questions

calendarw22-Nov-07 21:57

22-Nov-07 21:57

Thank you for your information.

And I would like to implement something like this:

public interface IReadOnlyDao
{
object GetById(object id);
IList GetAll();
}
public interface IReadOnlyDao<T, IdT> : IReadOnlyDao
{
T GetById(IdT id);
IList<T, IdT> GetAll();
}

But when I implementing the GetAll(), I got a problem that two method are same name and same parameter, is it possible to implement? or I am required to use convert the list using previous discuss method.

Thank you very much.

Andrei Ungureanu22-Nov-07 22:12

22-Nov-07 22:12

I think it will be better to use the converter. My opinion

I will use Google before asking dumb questions

calendarw22-Nov-07 22:14

add text drag and drop for a console application [modified]

22-Nov-07 22:14

Thank you very much~~
Smile | :)

carabutnicolae123422-Nov-07 20:20

carabutnicolae1234

22-Nov-07 20:20

how to add support for "text drag and drop" for a console application in .NET ?

it has to accept dropped text on the console window.

thanks.

Re: add text drag and drop for a console application

Vasudevan Deepak Kumar22-Nov-07 20:26

Vasudevan Deepak Kumar

22-Nov-07 20:26

A drop target must be there enabled in the application for it to accept drag and drop requests. Isn't it?

Vasudevan Deepak Kumar
Personal Homepage
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A pessimist sees only the dark side of the clouds, and mopes; a philosopher sees both sides, and shrugs; an optimist doesn't see the clouds at all - he's walking on them. --Leonard Louis Levinson

Re: add text drag and drop for a console application

carabutnicolae123422-Nov-07 20:31

carabutnicolae1234

22-Nov-07 20:31

not sure how I do this for a "Console" object.

Re: add text drag and drop for a console application

Vasudevan Deepak Kumar22-Nov-07 20:48

Vasudevan Deepak Kumar

22-Nov-07 20:48

Check out a reference drop target implementation here:

http://www.codeguru.com/cpp/com-tech/atl/atl/article.php/c3603/[^]

Re: add text drag and drop for a console application

carabutnicolae123422-Nov-07 21:22

carabutnicolae1234

22-Nov-07 21:22

hmm interesting, thanks,
still I was hoping for something more human Smile | :)

Displaying data one by one using timer

jacklynn_mei22-Nov-07 20:18

22-Nov-07 20:18

Hi...

I have problem with my timer code.
I want to display the data from the sql database on textbox using timer tick event.

For an example there are 3 data in the database which are apple,banana,coconut.
apple will appear first and after 10 seconds banana will appear, and after 10 seconds coconut will appear. And then, after the last data (coconut) appeared, the first data (apple) appeared again, and so on. It will continuously loop.

I want to do like this. Any suggestion or reference?

Thanks
Jac

Vasudevan Deepak Kumar22-Nov-07 20:21

Vasudevan Deepak Kumar

22-Nov-07 20:21

jacklynn_mei wrote:
It will continuously loop.

If you are looking at providing some interactive DHTML effect, I would suggest you look into:

http://script.aculo.us/[^]

Andrei Ungureanu22-Nov-07 20:28

22-Nov-07 20:28

Do you want to do this in a web or desktop application?

I will use Google before asking dumb questions

jacklynn_mei22-Nov-07 20:30

22-Nov-07 20:30

Winform Application

Andrei Ungureanu22-Nov-07 20:32

22-Nov-07 20:32

Then, why don't you just query the database, store what you have retrieved in an object, DataSet, List...whatever...and then at the specified interval you just show a value form that object (you can use in this case a counter too).

Hope it helps.

I will use Google before asking dumb questions

jacklynn_mei22-Nov-07 20:39

22-Nov-07 20:39

I have done something like the code below
But after reading the last data, it encounter error since there is no data persistent while reading.

public partial class tempA : Form
{
SqlDataReader m_Reader;
DataSet ds = new DataSet();
private void tempA_Load(object sender, EventArgs e)
{
string conStrg;
conStrg = ("Data Source=DIMENSION3000\\SQLEXPRESS;Initial Catalog=kMasjid;User ID=sa;password=123456");
SqlConnection connTimer = new SqlConnection(conStrg);
connTimer.Open();
string selSQL = "Select txtDesc FROM txtScroll";
SqlCommand com = new SqlCommand(selSQL, connTimer);
SqlDataAdapter da = new SqlDataAdapter(com);
da.Fill(ds, "txtScroll");
m_Reader = com.ExecuteReader();
m_Reader.Read();

Timer myTimer = new Timer();
myTimer.Interval = 5000;
myTimer.Enabled = true;
myTimer.Start();
myTimer.Tick += new EventHandler(Timer_Tick);
}
public void Timer_Tick(object sender, EventArgs e)
{
alphaTxtMain.Text = " " + m_Reader["txtDesc"];
m_Reader.Read()
}
}

Andrei Ungureanu22-Nov-07 20:46

22-Nov-07 20:46

 public partial class tempA : Form
{
SqlDataReader m_Reader;
DataSet ds = new DataSet();
int counter = 0;
private void tempA_Load(object sender, EventArgs e)
{
string conStrg;
conStrg = ("Data Source=DIMENSION3000\\SQLEXPRESS;Initial Catalog=kMasjid;User ID=sa;password=123456");
SqlConnection connTimer = new SqlConnection(conStrg);
connTimer.Open();
string selSQL = "Select txtDesc FROM txtScroll";
SqlCommand com = new SqlCommand(selSQL, connTimer);
SqlDataAdapter da = new SqlDataAdapter(com);
da.Fill(ds, "txtScroll");
m_Reader = com.ExecuteReader();
m_Reader.Read();

Timer myTimer = new Timer();
myTimer.Interval = 5000;
myTimer.Enabled = true;
myTimer.Start();
myTimer.Tick += new EventHandler(Timer_Tick);
}
public void Timer_Tick(object sender, EventArgs e)
{
alphaTxtMain.Text = " " + ds.Tables[0].Rows[counter++]["txtDesc"];
}
}

I will use Google before asking dumb questions

jacklynn_mei22-Nov-07 21:05

22-Nov-07 21:05

Thanks...
But after tried, it wont loop to the first data. After reading the 3rd data, it will error since there is no data on the position 3 (4th data) (my table only have 3 data).

Andrei Ungureanu22-Nov-07 21:12

22-Nov-07 21:12

Do we have to do everything for you? Test the counter...if it reaches the end of the DataSet, set it to 0.

I will use Google before asking dumb questions

jacklynn_mei22-Nov-07 21:25