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Hi
Im new to c#
Im using DAL which executes Datareader that returns a LIST<t> to my Business Layer which in turns passes it to the UI. I am trying to simulate
realtime instant searches with the text input box.
As a user types in a key, it again searches the db, and in turn updates the datagridlist.
On each key stroke a new list is being generated by the DAL
and passed to the gui.
The gui becomes abit slow and semi unresponsive.
The db query execute time worst case is around 20 miliseconds for each key stroke.
How do I get the GUI to be fully responsive while loading new lists for each stroke
IF there are better ways on doing this , I also like to know
thanks
Zak
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The UI thread still has to be able to redraw the datagrid, so there are a couple of things you can do to improve performance is to do the database searches in a background thread and pass that to a method you Invoke on the UI thread to bind to the new data and redraw the grid.
The other thing is pretty simple. Limit the number of records you're returning from the search. Typically, you'd only need to display one page of data on the grid so don't return any more than that.
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Have you considered not doing it that way, but filtering the binding source instead?
It's a lot easier, and means you don't need to issue new DB queries at all.
BindingSource.Filter[^]
Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952)
Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)
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In addition to the other suggestions, you might want to throttle your searches. If the user types four letters within half a second, they're probably not interested in seeing the search results for the first three.
Rx would be a good place to start:
http://rxwiki.wikidot.com/101samples#toc30[^]
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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i want to add new column in my database table like unique id (primary key ) when import excel file to a table then automatic generate new add column to a table (unique id ) following code:-
protected void btnUpload_Click(object sender, EventArgs e)
{
if (FileUpload1.HasFile)
{
string path = string.Concat((Server.MapPath("~/Data/" + FileUpload1.FileName)));
FileUpload1.PostedFile.SaveAs(path);
OleDbConnection OleDbcon = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties=Excel 12.0;");
OleDbCommand cmd = new OleDbCommand("SELECT * FROM [Sheet3$]", OleDbcon);
OleDbDataAdapter objAdapter1 = new OleDbDataAdapter(cmd);
OleDbcon.Open();
DbDataReader dr = cmd.ExecuteReader();
string con_str = @"Data Source=vaio\sqlexpress;Initial Catalog=dbemp;Integrated Security=True";
// Bulk Copy to SQL Server
SqlBulkCopy bulkInsert = new SqlBulkCopy(con_str);
bulkInsert.DestinationTableName = "tbdata";
bulkInsert.WriteToServer(dr);
OleDbcon.Close();
Array.ForEach(Directory.GetFiles((Server.MapPath("~/Data/"))), File.Delete);
Label1.ForeColor = Color.Green;
Label1.Text = "successfully inserted";
FetchData();
newrow();
}
else
{
Label1.ForeColor = Color.Red;
Label1.Text = "Please select the File";
}
}
public void FetchData()
{
SqlConnection con = new SqlConnection(@"Data Source=vaio\sqlexpress;Initial Catalog=dbemp;Integrated Security=True");
SqlCommand cmd = new SqlCommand("select * from tbdata", con);
con.Open();
SqlDataReader rdr = cmd.ExecuteReader();
GridView1.DataSource = rdr;
GridView1.DataBind();
}
public void newrow()
{
SqlConnection con;
SqlDataAdapter dladpt;
DataSet dldst;
DataTable mydt;
con = new SqlConnection(@"Data Source=vaio\sqlexpress;Initial Catalog=dbemp;Integrated Security=True");
dladpt = new SqlDataAdapter("select * from tbdata", con);
dldst = new DataSet();
mydt = new DataTable();
dladpt.Fill(mydt);
DataColumn dcolColumn = new DataColumn("Link", typeof(string));
mydt.Columns.Add(dcolColumn);
DataRow drowItem;
foreach (DataRow row in mydt.Columns)
{
drowItem = mydt.NewRow();
drowItem["Link"] = "secret";
mydt.Rows.Add(drowItem);
}
GridView1.DataSource = mydt;
GridView1.DataBind();
}
}
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Member 10578397 wrote: when import excel file to a table then automatic generate new add column to a
table (unique id )
ALTER the TABLE and ADD a COLUMN with an IDENTITY specification. It's done using SQL, not using datatables.
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
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Greetings all.
I have 10 tabs with names tabPage01 to tabPage10. Inside those tabs there are textboxes named pathTXT01 to pathTXT10. Under each textbox there is a checkbox named changePath01 to changePath10. That check box is supposed to toggle .readonly for the textbox above it. So here is my function
private void changePath_CheckedChanged(object sender, EventArgs e)
{
CheckBox checkTemp = sender as CheckBox;
string senderNumber = checkTemp.Name.Substring(checkTemp.Name.Length - 2, 2);
int tempMits = Convert.ToInt16(senderNumber);
string tempPathName = "pathTXT" + senderNumber;
TextBox papatrexas = ((TextBox)this.Controls[tempPathName]) as TextBox;
papatrexas.ReadOnly = !checkTemp.Checked;
}
Any help appreciated.
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There are much, much better ways to do this.
Have a look at creating a UserControl[^]. This allows you to create a new control in your toolbox which can contain (and encapsulate) the text box and the check box - so the check box always knows which text box it is supposed to affect: there is only one as far as it is concerned!
Your code then becomes:
private void changePath_CheckedChanged(object sender, EventArgs e)
{
papatrexas.ReadOnly = !changePath.Checked;
}And everything becomes a lot easier to read and work with.
Usercontrols have constructors, properties, methods, events - everything a "normal" control does, so you can even create a UserControl which contains the whole of your tab page - and then just add one to each page in your TabControl instead of individual controls!
I use them a lot: they let me modularise the form a lot better and save a heck of a lot of time and confusion!
Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952)
Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)
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Hi,
This is about ListView class in c#. I need one customization for it. I need ListView with "word wrap" option for labels in the ListView header. When value in some column is short, but header label of the column is wider, then you are forced to make the width of the column unnecessary wider. It takes space. If there would be word wrap option, it could fix this issue for me. I didn't find any good sample of fixing this issue except ObjectListView which is excessive for me.
I hope there is a solution for me.
Thanks in advance,
Galym
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If you're after a simple(ish) way, then just use WPF to create a ListView - you have full customisation of templates there. You can then just use an ElementHost to host it inside your Windows Forms application. There's no simple way in Windows Forms, because its implementation of ListView is just a thin wrapper of the Win32 version, so you have to drop down to effectively handling WM_OWNERDRAW.
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Hello all
em searching for help in scanning file on virustotal using virustotal api.
i have gone through most sources google directed me to.
please help. 
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Member 10579673 wrote: please help.
With what: you have not given us any idea where your problem lies?
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Hi,
i need to access public static member of one class into another class.
please provide the help. Learning c#.
Ex:
class ABC
{
static int nEllipsecount = 0;
// in some function increment nEllipseCount;
};
// class xyz in another file
class ABC;
class xyz
{
if(ABC :: nEllipseCount >0)
{
//Process these statements;
}
};
i couldn't be able access static value into to another class.
is my approach wrong ? Please help me to resolve.
Thanks & Regards,
Royal
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First, as you've shown it, nEllipsecount is NOT public.
In c# the default is private.
So, what you seem to want is:
class ABC
{
public static int nEllipsecount = 0;
}
class xyz
{
if (ABC.nEllipseCount >0)
{
}
}
If it isn't made public then you can't see it from xyz at all.
(Unless it is protected and you inherit from ABC.)
A positive attitude may not solve every problem, but it will annoy enough people to be worth the effort.
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Thanks alot Matt,
public static int nEllipsecount = 0;
In the above statement I'm declaring the static member in public only,
kindly tell me any other way i can declare as public.
Thanks & Regards,
Royal
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You can't declare a public member/method/class etc, with anything other than the public keyword. C# requires explicit scope declaration if you're trying to do anything other than declare something as private, which is the default scope. What are you trying to achieve because using a public static is generally not a good idea?
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Your code is hinting that you're working with C++ and not C#. Is this true??
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Even in C++, which this is, you should not do that.
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