C# Discussion Boards - CodeProject

Pls Help! How to reference the dynamically generate textbox ID

MyRunner20-Dec-06 5:05

20-Dec-06 5:05

Hi all,

I have a drop down control which let the user to select for creating number of textbox controls into the form. Once it generate the textboxes, I check the view source for each of the textbox control with _ctl0, _ctl1 ..... added in front of the textboxes'id. I need to get those value and insert into the DB. Here is my code behind.

private void btnMulitTextBox_Click(object sender, System.EventArgs e)
{

SqlConnection conn = ....;
conn.Open();
cmd = new SqlCommand("....", conn);
cmd.CommandType = CommandType.StoredProcedure;

int i = 0;
int totalnumofctrl = Convert.ToInt32(this.ddlNumtoGenerate.SelectedValue.ToString());

while (i < totalnumofctrl)
{
DoInsertToDB(i);
i++;
}
}

private void DoInsertToDB(int ctrlnum)
{
string textboxname ="_ctl" + ctrlnum + ":txtAName";
System.Web.UI.WebControls.TextBox tb = this.FindControl(textboxname) as System.Web.UI.WebControls.TextBox;
cmd.Parameters.Add("@AName", tb.Text);
cmd.ExecuteNonQuery();
}

I got "Object reference not set to an instance of an object." error everytime I run this. Any idea? Thanks in advance.

gsdg

Re: Pls Help! How to reference the dynamically generate textbox ID

Rob Graham20-Dec-06 5:56

Rob Graham

20-Dec-06 5:56

One would suspect that your "FindControl" method is failing to return a match, causing a null reference error in the next line of code. It might be helpful if you included the code for that (as well as the code that creates the textboxes so that we could see how they get named). In any case, you should check tb for null before using it.
Also, it appears that cmd is instantiated in the first method, and used many times in the second method, without clearing the parameters list before adding a new one by the same name.

Re: Pls Help! How to reference the dynamically generate textbox ID

Guffa20-Dec-06 6:24

Guffa

20-Dec-06 6:24

Stop spamming. You already have an active thread about this.

---
It's amazing to see how much work some people will go through just to avoid a little bit of work.

Socket listening

choopie20-Dec-06 2:59

choopie

20-Dec-06 2:59

I want to listen ip host with a specified port number. But not local ip address. I've tried to do it using three classes IPEndPoint, Socket, NetworkStream, but I couldn't see any data (in a MessageBox for example). I use:

private static string connectSocket(string address, int port)
{
//address = "10.0.105.4";
//port = 4000;
String data = null;
try
{
Byte[] bytes = new Byte[256];
IPEndPoint endPoint = new IPEndPoint(IPAddress.Parse(address), port);
Socket socket = new Socket(endPoint.AddressFamily,
SocketType.Stream, ProtocolType.Tcp);
socket.Connect(endPoint);
NetworkStream ns = new NetworkStream(socket);
Int32 i;
while((i = ns.Read(bytes, 0, bytes.Length)) != 0)
{
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
}
return data
}

Does anyone know how to solve this?

Re: Socket listening

Eitsop20-Dec-06 4:14

Eitsop

20-Dec-06 4:14

Err... The line that goes:

data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);

Should you appending? i.e.

data += System.Text.Encoding.ASCII.GetString(bytes, 0, i);

It is that simple, just adding the data += instead of data = ?

- Eitsop

What we do not understand we do not possess. - Goethe.

Re: Socket listening

choopie20-Dec-06 6:04

choopie

20-Dec-06 6:04

Thanks but still it should return to me any data without appending.

getting the checked items

quiteSmart20-Dec-06 2:37

quiteSmart

20-Dec-06 2:37

How to get the checked items in a checkedListBox?

I don't want a return value of CheckedListBox.CollectionItems

i want it as a string array.

thanks

Re: getting the checked items

Stefan Troschuetz20-Dec-06 2:53

Stefan Troschuetz

20-Dec-06 2:53

Get the collection returned by CheckedListBox.CheckedItems, create a string array of the same size as the collection and for each collection item put an appropriate string into the array.

"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning." - Rick Cook

www.troschuetz.de

Delegate And Event

ronivars20-Dec-06 2:31

ronivars

20-Dec-06 2:31

hi there

i saw a lot of Example and Article for Delegate and Events

i need to know where to use delegate and events

let's say for example

user need 2 insert in args 3 parameter

//static void Main(string[] args)

like add 2 3 //program will output 5

or sub 3 2 //program will output 5

can i use delegate here ???

without ask if add or sub

can somebody give me example from life?

thanks in advance
Smile | :)

Re: Delegate And Event

Tristan Rhodes20-Dec-06 5:35

Tristan Rhodes

20-Dec-06 5:35

To start with -

A Delegate is a pointer to a function

An Event is a collection of delegates.

<br />
<br />
public void Run()<br />
{<br />
  int i = Add(a,b);<br />
  Console.Write(i);<br />
}<br />
<br />
public int Add(int a, int b)<br />
{<br />
  return a + b;<br />
}<br />
<br />

will do exactly the same as

<br />
// A delegate specifying it can hold a function that takes two integers as arguments.<br />
delegate void Adder(int a, int b);<br />
<br />
public void Run()<br />
{<br />
  // Create a new delegate containing the "Add" function defined below.<br />
  Adder a = new Adder(Add);<br />
<br />
  // Set i to the value of the result of the function contained by a.<br />
  int i = a(a,b);<br />
<br />
  Console.Write(i);<br />
}<br />
<br />
public int Add(int a, int b)<br />
{<br />
  return a + b;<br />
}<br />
<br />

For more information on events, create a windows form application and do a tutorial.

Hope that helps

Tris

Re: Delegate And Event

ronivars20-Dec-06 21:41

ronivars

20-Dec-06 21:41

hi tris
thanks for the answer
i know how to use delegate and events
all the article explain how to use delegate and events
but not when or where to use it

i found some example for delegate

let's say if we need to sort some array once Ascending
and once descending without change the function BubbleSorter
we use delegate

delegate bool CompareOp(object lhs, object rhs);

class MainEntryPoint
{
static void Main()
{
Employee [] employees =
{
new Employee("Bugs Bunny", 20000),
new Employee("Elmer Fudd", 10000),
new Employee("Daffy Duck", 25000),
new Employee("Wiley Coyote", (decimal)1000000.38),
new Employee("Foghorn Leghorn", 23000),
new Employee("RoadRunner'", 50000)};

CompareOp employeeCompareOp = new CompareOp(Employee.RhsIsGreater);
BubbleSorter.Sort(employees, employeeCompareOp);
PrintEmployee(employees);

CompareOp employeeCompareOp1 = new CompareOp(Employee.RhsIsSmall);
BubbleSorter.Sort(employees, employeeCompareOp1);
PrintEmployee(employees);

Console.ReadLine();
}

private static void PrintEmployee(Employee[] employees)
{
for (int i=0 ; i<employees.length ;="" i++)
="" console.writeline(employees[i].tostring());

="" }

="" }

="" class="" employee="" :="" object
="" {
="" private="" string="" name;
="" decimal="" salary;

="" public="" employee(string="" name,="" salary)
="" this.name="name;
" this.salary="salary;
" override="" tostring()
="" return="" string.format(name="" +="" ",="" {0:c}",="" salary);
="" static="" bool="" rhsisgreater(object="" lhs,="" object="" rhs)
="" emplhs="(Employee)" lhs;
="" emprhs="(Employee)" rhs;
="" (emprhs.salary=""> empLhs.salary) ? true : false;
}

public static bool RhsIsSmall(object lhs, object rhs)
{
Employee empLhs = (Employee) lhs;
Employee empRhs = (Employee) rhs;
return (empRhs.salary < empLhs.salary) ? true : false;
}
}

class BubbleSorter
{
static public void Sort(object [] sortArray, CompareOp gtMethod)
{
for (int i=0 ; i

Re: Delegate And Event

ronivars20-Dec-06 21:50

ronivars

20-Dec-06 21:50

hi again
sory for long code before

events

scenario for events
driving in the race car
need to alert driver
when the fuel gone finish
with red lamp on display

how my program ready for this scenario??

how can i fire event for this

thanks in advance

roni

How to Sort HtmlElementCollection

zaboboa20-Dec-06 2:27

zaboboa

20-Dec-06 2:27

Hello,

I have HtmlElementCollection object. Althought it is a collection, it does not have the Sort() method. How can I sort that collection using IComparer interface? Same goes for FileInfo[] object, it does not have Sort() method, and I need to sort that as well.
Thank you.

Re: How to Sort HtmlElementCollection

Stefan Troschuetz20-Dec-06 3:00

Stefan Troschuetz

20-Dec-06 3:00

Don't have a solution for the collection problem, but to sort an array you can use an overload of the static Array.Sort method.

Re: How to Sort HtmlElementCollection

Ravi Bhavnani20-Dec-06 3:57

Ravi Bhavnani

20-Dec-06 3:57

See this[^] article.

/ravi

This is your brain on Celcius
Home | Music | Articles | Freeware | Trips
ravib(at)ravib(dot)com

Playing a sound using Media.Soundplayer()

QzRz20-Dec-06 2:04

QzRz

20-Dec-06 2:04

Hello

I'm creating an application which use the Media.Soundplayer function.
Currently i'm using a Media.Soundplayer funtions that Play when i press on different buttons, it works perfectly.

I tried to create a new Media.SoundPlayer and load a file which should be looping while the application is running, but when i use the Media.Soundplayer it stop the previous file and start play the new one.

So can anyone tell me how to play a file without it stop play unless i tell it to stop?

This is how i load the files:
private System.Media.SoundPlayer TrykPaaKnap = new SoundPlayer(Geografika.Properties.Resources.tryk);

private System.Media.SoundPlayer BGMusik = new SoundPlayer(Geografika.Properties.Resources.Fjederdansen);

Thanks

Internationalize the application

AcDev720-Dec-06 2:03

AcDev7

20-Dec-06 2:03

Hi
I have been working on a windows application. Now I want to Internationalize the application. I want to add a new languages (Chienese). For this purpose I have created the resource file.

My question is how do I type the chinese words in the resource file. I have tried and failed to either copy or write anything the resource file(in chinese) in Visual Studio IDE.

If any one knows about it please tell me

Thanks
Avik

Avik

Re: Internationalize the application

Netricity20-Dec-06 11:40

Netricity

20-Dec-06 11:40

Perhaps it is due to the unusual Chinese characters? The string resource editor will xml-encode things such as < but may be not handle Chinese characters. You can open a string resource file in Notepad and enter them that way, but you may need to xml-encode the following characters
"
&
<
>
and change all apostrophes to ' before pasting them in.

Sorry if this doesn't help you.

Finding controls inside a region ?

kkadir20-Dec-06 1:51

kkadir

20-Dec-06 1:51

Hi there,

I have a problem which I expect to solve here.. Here is what I want to do :

I have got 5 sub panels and 1 main panel (all of them containing various controls) .. I want to do simple drag&drop operations on them. To be more clear I will drag the main panel over one of the sub panels.

Now, where I stuck is that when I drop the main panel anywhere in the Form a method should check wether there is a sub panel in the region of the main panel. If yes the main panel will transfer its controls to that sub panel. If no the main panel will return to its original position.
But also, in the region there may be two panels. In this case the main panel will transfer its contents to the closest one.

How can I do such region checks and also how can I compute the closest one ?

Thanks for your helps and best regards...

.:: Something is Wrong ::.

uploaf files using desktop applications

Mridang Agarwalla20-Dec-06 1:15

Mridang Agarwalla

20-Dec-06 1:15

Hey guys,
My application performs a backup of some files, add them into a single archive and then uploads them to a one click hoster such as Yousendit.com or sendspace.com. If you open the main page of YouSendIt.com you will a browse file button similar to the ones found on other webpages. I'm am able to upload using the website but i wanted to do so from my application. How do i do this? The website doesnt require any authentication.

Re: uploaf files using desktop applications

Eitsop20-Dec-06 2:37

Eitsop

20-Dec-06 2:37

Have you looked at the response a file browse sends? You'll probably have to POST a response. If you're using the .Net Web name space you should be able to use the WebClient.Upload file method.

You may need to set various other fields as well before uploading the file.

- Eitsop

What we do not understand we do not possess. - Goethe.

Re: uploaf files using desktop applications

Mridang Agarwalla20-Dec-06 9:36

Mridang Agarwalla

20-Dec-06 9:36

I'm really new to we stuff using .net so it'd be a great help if you could gimme an example. i couldn't find much resources about this.

XmlSerialier reflection error ??

babbelfisken20-Dec-06 1:00

babbelfisken

20-Dec-06 1:00

Hi!

Basically i want to serialize an array of objects Booking.
That class has public fields of basic types like string,int.
A very simple class containg information of the booking.

I have managed to serialize/deserilize the array before but when
i added a public field object of type 'MyButton' which inherits the System.Windows.Forms.Button class i got Reflection error of type Booking[] ?

I tried using an [XmlIgnore] on the object not to serializr this but it doesn't work.

Booking class:

<br />
<br />
string name;<br />
...;<br />
...;<br />
<br />
public Booking(string name,...,...)<br />
{<br />
  this.name = name;<br />
  ...;<br />
  ...;<br />
<br />
  myButton = new MyButton();<br />
}<br />
<br />
...;<br />
<br />

I have a booking manager class that takes care of every booking and also instantiate the xmlSerializer object with the following line

<br />
xmlSer = new XmlSerializer(typeof(Booking[]));<br />

As I said, it worked fine until I added the MyButton object to the Booking class!

Why can't I add an object to my class with the property of XmlIgnore on it and serialize that object ?

Can't get a grip of what reflection error really means too!

Thankful for suggestion on how to solve this. I want to use this XmlSerializer cause it makes the job a lot easier but if i cant workaround this problem I may have to build an xmldocument by hand and save it and i try to avoid it.

Re: XmlSerialier reflection error ??

Eitsop20-Dec-06 2:42

Eitsop

20-Dec-06 2:42

When you say XmlIgnore, do you mean that you have applied the XmlIgnoreAttribute? i.e.

/* This field will be ignored when serialized--
   unless it's overridden. */
[XmlIgnoreAttribute]
public string Comment;

- Eitsop

What we do not understand we do not possess. - Goethe.

Re: XmlSerialier reflection error ??

babbelfisken20-Dec-06 3:05

babbelfisken

20-Dec-06 3:05

What I have on my "public MyButton myBut;" is an
[XmlIgnore]

Could it be that the XmlSerializer have trouble serializing objects like Button,Label classes because they have to do something with Windows?

Or perhaps that my object class is inheriting the Button object?

From one confused guy..

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.