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I am new to C# so Im trying to learn on my own. I need to disable a text box until a check box is checked. The reference material I've looked at so far has not helped me so in addition to help with this issue I would also appreciate suggestions on helpful references for learning C#.
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myTextBox.Enabled = false, from memory.
Inside C# second edition, by Tom Archer, MVP
Christian Graus - Microsoft MVP - C++
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In your form constructor, set the textbox's Enabled property to false. Then, add an event handler for the checkbox's Checked event and in it, switch the textbox's Enabled property to true.
As far as reference material goes for C# itself, I love Tom Archer's Inside C#. That's the way to learn C#. (Although I've never read it, I hear that Jesse Liberty's Programming C# is also quite good. I can't believe it would be better than Tom's book though.)
Once you read that, you should read Jeffrey Richter's Applied Microsoft .NET Framework Programming for an excellent read on the CLR and the .NET Framework itself.
I would recommend the following for Windows Forms programming: Programming Windows with C# by Charles Petzold is very well written and quite large. Either that or Windows Forms Programming in C# by Chris Sells.
And for ASP.NET Programming, I've heard from many beginning ASP.NET people that Programming ASP.NET by Jesse Liberty is excellent. However, if you're comfortable with C# and .NET programming in general, then I highly recommend jumping straight into the deep end with ASP.NET and taking a look at Fritz Onion's Essential ASP.NET With Examples in C#.
Hope that helps. 
[Cheshire] I can't afford those plastic things to cover the electric sockets so I just draw bunny faces on the electric outlets to scare the kids away from them...
[RLtim] Newsflash! Kids aren't afraid of bunnies.
[Cheshire] Oh they will be...
-Bash.org
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Hi
I am having all sorts of grief with comparing two datasets when not directly editing the second dataset it's self, but rather populating it from the database, which HAS had updates, additions and deletes performed on it.
Currently I construct 3 datasets.
1. Original
2. Updated (by repopulating DS from changed table)
3. Changes (populated by merging 1 & 2 and calling GetChanges() )
Am I wrong in assuming the dataset is smart enough to do this? Or would I be better of writting a bunch of classes and then implement IComparable?
Thanks in advance!
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Hi i am new to the .Net platform and after learning the basics and going further up for about 40 days and 40 nights (:P), i am stuck at a challenge. i have been given a task to set up a web service that Screen Scrapes web pages of my college and associates with these pages a relevant RDF file. A client using this service should than be able to use the RDF file in order to associate similar web pages.
Can somone provide me with the details as where to take the start from...i am able to handle screen scraping thing a bit but dont know much about the second part of the task....i have studied a lot of material available on internet about RDF and the semantic web but still not sure as how to use the knowledge using C#.
Asim Nazir
Student
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Hi there,
I can't help you out right now, but i saw some similairity in what you're looking for and what i'm looking for.
See thread: http://www.codeproject.com/script/comments/forums.asp?forumid=1641#xx1200889xx[^]
Like you i'm new to .NET (primairly focusing on C#, ASP.NET and SQL2000) and interrested in what you learn about these subjects. If i find something that could help you with your task i'll let you know.
What is a RDF file anyway?
Goodluck soldier!
Just give me the blue pill...i dont want to go down into rabbitholes...
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Thanks for the attention to my post!!
RDF means Resource Development Framework. The Semantic Web ( http://www.w3.org/2001/sw/ and http://infomesh.net/2001/swintro/) is an effort to put meaning into web pages by the inclusion of meta-data. This meta-data usually takes the form of an XML dialect called RDF. so RDF file actually is a metadata file containing information about the website, so that in the future may be all the websites will have an associated RDF file and the search engines will query the RDF files in order to extract the useful info. This is what i have understood about this RDF stuff till now.
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I am able to copy files using the c# FileInfo class by specifying a UNC for the file name. This works great for copying files from one computer to another computer until my application does not have access to the source computer. How do I log onto the source computer with a network user name and password, and then copy the file off of that computer onto my local drive?
Thank you!
RobC
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I am facing problem to connect oracle server with predefined datasource. Can anyone please tell me how can i create a connection with (ip address) , (orcale instance), (username) and (password).
Please also provide me few lines of code, to update a table with using parameters. I attemted sql like "update <tablename> set <field> = ? where pk = ?", but it did not work at all.
love2code
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I really did work very little with Oracle for one project, but if I remember correctly, you need to install some client software, and it's in that software that you set up the connection to the server. In you .NET code (using Oracle Data Provider) your connection string basically looks like this:
Data Source=schema name;User Id=user name;Password=password" As you can see, no server information is there.
As for the parameter question, its something like this:
string sql = "UPDATE Table SET Field1 = :p_Field1 WHERE Field2 = :p_Field2";
OracleCommand cmd = new OracleCommand(sql, conn);
cmd.Parameters.Add("p_Field1", someValue);
cmd.Parameters.Add("p_Field2", someOtherValue);
cmd.ExecuteNonQuery();I hope this helps a little. Good luck!
-- LuisR
Luis Alonso Ramos
Intelectix - Chihuahua, Mexico
Not much here: My CP Blog!
The amount of sleep the average person needs is five more minutes. -- Vikram A Punathambekar, Aug. 11, 2005
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Thanks, Luis
My parameters problem has been solved.
But think those situation where my client machine has .net installted and oracle net client installed. When i run my program from that machine, it continues searching Oracle Server. My program does not know the Orcale [alias] or [data source] configured at that machine.
Please provide me such Microsoft Solution.
Thanks again.
PK Biswas, India.
love2code
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Still a tree view control bugs me. In the Windows Explorer and other apps (Studio comes to mind) when you're dragging things over a Tree View control, you get a highlight on the tree item you're currently dragging over. This doesn't want to happen in my own .NET application. Is there some property I can set, or do I have to import something from the Platform SDK? Thanks for your help.
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Try setting
treeview.AllowDrop = true;
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Oh, I'm sorry--to clarify, I already have a lot of drag/drop functionality coded (you can already drag/drop, cut/paste/copy etc like in Windows Explorer. I just don't have a drop highlight like I want, and I'm hoping there's a simple property/style to set, instead of needing to add yet another member var so I can highlight it manually. Doing more manual highlighting is bad since it seems to cause flickering.
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override OnDragEnter on the TreeView and change the DropEffect
eg
protected override void OnDragEnter(DragEventArgs drgevent)
{
TreeViewDataFormat dragData = (TreeViewDataFormat) drgevent.Data.GetData(typeof(TreeViewDataFormat));
if (dragData != null)
{
//Do sone stuff
drgevent.Effect = DragDropEffects.Move;
}
}
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Well, I anwered my own question.
Should anyone else chance to search for an answer on how to get drop highlights on tree view controls, look no further than Tree View Common Control.
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hi, when I use this bit of code to get the number of files with the extensions ".mp3, .wma, and .wav" as follows:
int number_of_files = Directory.GetFiles(folderBrowserDialog1.SelectedPath, "*.mp3;*.wma;*.wav", SearchOption.AllDirectories).GetLength(0);
it doesn't return any results. (the number_of_files integer is still 0). I tried this using only *.mp3 and got some results. Why doesn't this work? Am I not supposed to use the semi-colon symbol? IF so which one am I supposed to use? Thanks for your help.
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I think second parameter is a simple pattern, not a regexp.
You can't do things like *.mp3|*.mpg
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so what can I do? I'd prefer to not have to have multiple lines as when I eventually have to add found file strings to an array, it'll be somewhat confusin and if there's another way, needless. any ideas? thanks again.
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Write a method like this:
<br />
public void findFiles(string where, bool recurse, params string[] what){ }
so you can invoke without arrays:
<br />
findFiles("c:\\", true, "*.mp3", "*.avi");<br />
findFiles("d:\\", false, "*.mp3");
and so on.
hope this helps
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Hi Everyone,
I am facing a problem while using DropDownList. Actually I am retrieveing company name from Sql server and displaying on DropDownList (value + id).
If I select DropDownList(just like combo box), it displays me 1st records corresponding to that record(ID). But if I click 2nd,3rd and fourth and so on from DropDownList company name , every time it displays me only 1st record on textbox.
//////////////This is server side program(Update.aspx)//////////////
<%@ Page language="c#" Codebehind="Update.aspx.cs" AutoEventWireup="false" Inherits="Myprogram.Update" %>
| Select Company Name:
| asp:DropDownList id="DropDownList1" AutoPostBack="True"
OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged" runat="server"
Width="160px" Height="16px"
DataTextField="Display" DataValueField="Value">
/asp:DropDownList>
| | Customer Name:
| <asp:textbox id="txtCustomerName" runat="server" width="160px">
|
/////////Update.aspx.cs////////////
protected void DropDownList1_SelectedIndexChanged(object sender, System.EventArgs e)
{
if(this.SelectedItemCombo)
{
DetailsOfRecords();
}
}
protected void DetailsOfRecords()
{
thisConnection.Open();
thisCommand = thisConnection.CreateCommand();
thisCommand.CommandText = " SELECT * from Customers where CustomerID=" + this.DropDownList1.SelectedValue.ToString();
thisReader = thisCommand.ExecuteReader();
while(thisReader.Read())
{
string strID = thisReader["CustomerID"].ToString();
if(strID == this.DropDownList1.SelectedValue.ToString())
{
this.txtCustomerName.Text = thisReader["CustomerName"].ToString();
this.txtCompany.Text = thisReader["Company"].ToString();
}
}
thisReader.Close();
thisConnection.Close();
}
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where is your databind() ? in page_load ?
if I understand your problem, I'm quite sure you've not checked if ispostback before databind().
try (in Page_Load):
<br />
if(IsPostBack == false) {<br />
<br />
DropDownList1.DataBind();<br />
}<br />
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Thanks for solving my one problem.
But I am still facing problem. If I select company name from Dropdownlist it does not showing me corresponding record on the textbox(like customer name,address,phone number and so on.
protected void DropDownList1_SelectedIndexChanged(object sender, System.EventArgs e)
{
if(this.SelectedItemCombo)
{
DetailsOfRecords();
}
}
protected void DetailsOfRecords()
{
thisConnection.Open();
thisCommand = thisConnection.CreateCommand();
thisCommand.CommandText = " SELECT * from Customers where CustomerID=" + this.DropDownList1.SelectedValue;
thisReader = thisCommand.ExecuteReader();
while(thisReader.Read())
{
string strID = thisReader["CustomerID"].ToString();
if(strID == this.DropDownList1.SelectedValue.ToString())
{
this.txtCustomerName.Text = thisReader["CustomerName"].ToString();
this.txtCompany.Text = thisReader["Company"].ToString();
this.txtEmailAddress.Text = thisReader["Email"].ToString();
}
}
}
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hum...
1- if that snippet is in a codebehind, than your class inherits from System.Web.UI.Page which does not contains SelectedItemCombo). So the question is: what is SelectedItemCombo ?
2- doing sql like that in callbacks is a bad idea
3- doing sql without try{}catch{}finally{} is even worst
4- replace while(thisReader.Read()) with: if(thisReader.Read()): is less confusing. But: why not DataSet?
5- replace if(strID == this.DropDownList1.SelectedValue.ToString()) with if(strID.Equals(this.DropDownList1.SelectedValue.ToString()))
hope this helps
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Thanks for your help.
bool SelectedItemCombo. Actually I have ready made this program in C#(winform) So where I used it.
Once I remove it from my program in ASP.NEt it is working fine.
Once again Thanks.
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