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i have designed a code that will add a control on panel of the form and then if i want to delete it it will delete the code by pressing delete key.
the control code is as follows
public partial class NO : UserControl
{
public NO()
{
InitializeComponent();
}
private void NO_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
Point[] points = { new Point(0, 42), new Point(15, 42), new Point(15, 25), new Point(15, 63), new Point(30, 25), new Point(30, 63), new Point(30, 42), new Point(47, 42) };
g.DrawLines(Pens.Black, points);
g.Dispose();
}
private void txt_no_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 13)
{
lbl_no.Text = txt_no.Text;
lbl_no.Visible = true;
txt_no.Visible = false;
}
}
private void lbl_no_DoubleClick(object sender, EventArgs e)
{
lbl_no.Visible = false;
txt_no.Visible = true;
}
}
while the control is added on the form on a click event
private void NO_Click(object sender, EventArgs e)
{
NO no_obj=new NO();
no_obj.Location = new Point(x, y);
fpanel1.Controls.Add(no_obj);
x += 50;
no_obj.Click += new EventHandler(no_obj_Click);
}
void no_obj_Click(object sender, EventArgs e)
{
c = (NO)sender;
c.KeyDown += new KeyEventHandler(c_KeyDown);
}
void c_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Delete)
{
fpanel1.Controls.Remove(c);
}
}
the code works fine on click event.
my problem is that when i insert any text in text box and then try to delete my control using DELETE key it will not delete it.
plz send some suggestion so that i m able to resolve this problem on keypress event.
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Hello,
trulyyy wrote: my problem is that when i insert any text in text box and then try to delete my control using DELETE key it will not delete it.
The problem is that the TextBox holds the focus and the KeyDown event of the UserControl doesn't get fired.
You also have to handle the MouseDown of all other Controls (including TextBox) which are on the UserControl.
But anyway, this code is a big mess!
Please try to use meaningfull names, and also use the "pre"-Tags if you post code here on the forum.
trulyyy wrote: void no_obj_Click(object sender, EventArgs e)
{
c = (NO)sender;
c.KeyDown += new KeyEventHandler(c_KeyDown);
}
If the user Clicks the second time on the UserControl you will have the KeyDown fired twice.
trulyyy wrote: g.Dispose();
This is a very bad idea, and will have strange effects in your program.
You should not Dispose objects which you have not created.
All the best,
Martin
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i have design a controle using following code
private void NO_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
Point[] points = { new Point(0, 42), new Point(15, 42), new Point(15, 25), new Point(15, 63) };
Point[] points2={ new Point(30, 25), new Point(30, 63), new Point(30, 42), new Point(47, 42) };
g.DrawLines(Pens.Black, points);
g.DrawLines(Pens.Black, points2);
g.Dispose();
}
private void lblNO_Click(object sender, EventArgs e)
{
lblNO.Visible = false;
txtNO.Visible = true;
}
private void txtNO_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 13)
{
lblNO.Text = txtNO.Text;
txtNO.Visible = false;
lblNO.Visible = true;
}
}
private void NO_Click(object sender, EventArgs e)
{
this.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
}
when i placed it on form and then i want to delet it
i am using the following code for that purpose
private void button1_Click(object sender, EventArgs e)
{
NO un = new NO();
un.Location = new System.Drawing.Point(X, Y);
un.Refresh();
un.Size = new Size(100, 100);
Controls.Add(un);
un.Click += new EventHandler(un_Click);
X += 50;
}
void un_Click(object sender, EventArgs e)
{
c = (UserControl)sender;
c.KeyDown += new KeyEventHandler(c_KeyDown);
}
void c_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Delete)
{
this.Controls.Remove(c);
}
}
but when i dont touch the control and as it delete it
it would be deleted when i change the value of lable on control the above code is not working.
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cuteAisha wrote:
g.Dispose();
Don't dispose a graphics object that you haven't created yourself.
cuteAisha wrote: but when i dont touch the control and as it delete it
it would be deleted when i change the value of lable on control the above code is not working.
I have no idea what you are trying to say. I get that the code is not working, and that it has something to do with changing the value of the label, and something about deleting the control. I can't tell what's happening or if the control is deleted when it shouldn't or if it isn't deleted when it should.
---
single minded; short sighted; long gone;
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i want to delete control on key press
control is generated on click event of button
when user click lable on control a textBox is displayed
user may enter input for control funtion in the text box
when user press enter key text of textBox is assign to lable
and its visible property is equal to false.
this code which is given on forum proved all above funtionality
but when user assing a input now that control is not delete
on the other hand if user don't click on input lable now that coutrol will deleted
i cant undestand what the problem is?
why in some conditions it working and why not in a scecific condition.
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Hi,
I dont understand all of it;
not using the PRE tags makes this harder to read than is necessary.
But with what I can figure out, seems to me there are many mistakes:
1.
g.Dispose(): as Guffa already said, dont dispose of things you did not create.
2.
I am puzzled by your NO_Click()
cant figure out what control would invoke this, nor what sense it makes
just changing a border style.
Showing the constructor might have been useful...
3.
on button1_Click you create a new NO
so every time it happens another NO is added, 50 dots to the right of the
previous one? is that really the intention?
if you only need either none or one NO object, I suggest you create it beforehand
(probably using Designer) and keep it invisible until you want to see it.
4.
un_Click(): why is it you set the keydown event only after having clicked "un" ?
I guess you could have done that right away, it would only fire when is has
focus anyway. You are making things more complex than necessary.
5.
it might help us if you better explain (and show code about):
- what the intial state should be and is;
- what the functionality of the NO class is;
- and exactly what goes wrong, after exactly which actions the user takes.
But maybe you first want to clean-up your code based on the above input,
then replublish it inside PRE tags (have a look at other messages, then
use the little "pre" button under the window where you enter your messages...
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i want to know how to connect the application to the db and create the user logins in the db via the application.do you have any idea....
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prasadbuddhika wrote: i want to know how to connect the application to the db
SqlConnection conn = new SqlConnection(theConnectionString);
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandText = anySqlCommand;
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();
theConnectionString is defines where and how to connect to your database. For the functions you wish to carry out you will need a connection with sysadmin privileges. See http://www.connectionstrings.com[^] for details on what connection strings look like.
anySqlCommand is a string that can be pretty much any command that SQL Server understands. You can even dump entire scripts in there. The only thing it can't deal with is the GO, because that isn't SQL, it is a delimiter that Query Analyzer or the SQL Server Management Studio uses to separate batches of SQL statements.
Upcoming events:
* Glasgow: Mock Objects, SQL Server CLR Integration, Reporting Services, db4o, Dependency Injection with Spring ...
"I wouldn't say boo to a goose. I'm not a coward, I just realise that it would be largely pointless."
My website
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Hi,
I have a form Form1 I want to refresh the form after every 10 seconds how to implement this.
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you can just use a timer from System.Threading namespace.
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Hi Ekynox,
Thanks for reply....
Actually I have a DataGridView in Form1 in my Windows Application and now i want to refresh the datagridview every some time....
Can u help me with a sample code....
![Rose | [Rose]](https://codeproject.freetls.fastly.net/script/Forums/Images/rose.gif)
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do you know how to fill a datagridview ? then put the code that fills a datagridview inside the timer object. cant be that hard.
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hi all,
i m new in C#, can anyone hlep me to return values from an ArrayList??
coz in arraylist u can add multityes of values, so how can i return these multitype values from a single return function??
please help me.
thanks
Baljit Singh Grewal
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You return the arraylist itself.
If you're using C# 2.0, you should never use ArrayList, use the generic List class instead. And if you're using 1.0 or 1.1, stop if you can. The C# 2.0 Express Edition is free.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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Obviously you are new to posting in forums also. 
You should choose a subject line that describes the area of your question. A general greeting is not useful at all as a subject.
Also, your question is pretty vague, so it's hard to offer any suggestions.
The return value from a function has to be a single entity, so if you have multiple values, you have to put them into some kind of data type that supports multiple values, like an ArrayList.
---
single minded; short sighted; long gone;
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Please don't post the same question twice.
How does a string have a max or min value, by what rules ?
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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You could create a user defined function in SQL Server 2005 to give Min and Max of a String, which you would have to define the rules of what is the Max of a string and Min of a string.
"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon
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hi all
i wount to select max(string)from database
the database is sql server2005
who i can do tht without do any thing in code(c#)
thanks for any body help me
![Rose | [Rose]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/rose.gif)
Thaer
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Don't post the same question twice, please 
"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon
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I've used C# for a few years now and have not needed to use its pointers feature. However, I'm in the process of optimizing some code, and I'm looking at pointers as one way to improve performance. The code I'm working with makes extensive use of arrays. Lots and lots of tight loops in which the results are assigned to elements in a array.
I wrote the following console app to compare pointer performance to array performance:
using System;
using System.Diagnostics;
namespace PointerTest
{
class Program
{
private const int Size = 10000000;
static void Main(string[] args)
{
Stopwatch watch = new Stopwatch();
float[] data = new float[Size];
unsafe
{
fixed(float* p = data)
{
watch.Start();
for(int i = 0; i < Size; i++)
{
p[i] = 1.0f;
}
watch.Stop();
Console.WriteLine("Pointer: " + watch.Elapsed.ToString());
}
}
watch.Reset();
watch.Start();
for(int i = 0; i < Size; i++)
{
data[i] = 1.0f;
}
watch.Stop();
Console.WriteLine("Array: " + watch.Elapsed.ToString());
Console.Read();
}
}
}
The program assigns 10 million items to a pointer pointing to an array and then does the same thing with the array directly. Here are the results:
Pointer: 00:00:00.1147978
Array: 00:00:00.0993352
I ran the program several times, and while the times varied, though not by a great amount, the result was the same: the pointer method is slower.
However, when I used an array size below about 20,000, the pointer method beat out the array method by a small amount.
Any thoughts or insights?
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That matches what I have found as well, as I mentioned in this article[^]. I don't know the reason for it, but I've always found it to be so. Perhaps it could have to do with some extra checks that might done for pointers that are omitted with arrays because the JIT can make assumptions about arrays that it can't about pointers. It would be interesting to find out for sure what the cause is - but atm I unfortunately don't have the time to go poking around in the generated machine code.
--Justin,
Microsoft MVP, C#
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Leslie Sanford wrote: Any thoughts or insights?
I like open questions... they indicate wisdom: either awareness of ignorance,
or a truely open mind!
In my experience measuring performance by looking at elapsed time is very good
if some precautions have been taken:
1.
the time must be long enough to average out some statistical disturbances, typically
things the system may do in the background; that's disk accesses, Ethernet
packets, anti-virus, whatever. I would suggest to increase the job tenfold.
2.
Be careful with the special situation for the first experiment: if your tests
share something (such as an array), it will not have been allocated in physical
memory, it will not yet have been (partially) loaded in level3 or L2 cache, etc.
Quite often, when comparing two alternatives, the second wins, not because
it is faster, but just because it gets the better starting conditions.
So the minimum one should do is swap both to see how much of a difference that
gives.
My approach to cover both issues typically is to perform all N different tests
one after another, but then loop over it for say 100 times.
Then either ignore the first iteration entirely, and/or do some statistical
analysis on those N result arrays.
But even then, for N>2 the order of the tests may also be significant, so it
might be better to sequence them at random.
Hope this helps.
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Luc Pattyn wrote: I like open questions... they indicate wisdom: either awareness of ignorance,
or a truely open mind!
Thank you!
Luc Pattyn wrote: Quite often, when comparing two alternatives, the second wins, not because
it is faster, but just because it gets the better starting conditions.
So the minimum one should do is swap both to see how much of a difference that
gives.
You are right! I changed the order of the test and got nearly opposite results. The pointer method beat out the array method repeatedly.
Luc Pattyn wrote: My approach to cover both issues typically is to perform all N different tests
one after another, but then loop over it for say 100 times.
Then either ignore the first iteration entirely, and/or do some statistical
analysis on those N result arrays.
But even then, for N>2 the order of the tests may also be significant, so it
might be better to sequence them at random.
I rewrote the test using a smaller array. Then I ran the tests in a loop 10000 times. The pointer method beat out the array method by a small amount. I changed the order of the tests within the loop and got the same results. I ran the app several times and got consistent results.
It would seem that the pointer method may be faster based on my tests. I'll have to decide if the possible gain in speed is enough to justify changing my code. And perhaps improve my tests by doing a more thorough analysis of the results.
Luc Pattyn wrote: Hope this helps.
Absolutely! It's been an eye opener. Thank you.
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