C# Discussion Boards - CodeProject

Heath Stewart11-Oct-04 10:56

11-Oct-04 10:56

You mean like the "File Created" date that every file on FAT/32, NTFS, and most other file systems has? If you want to access this from code, use the FileInfo class along with the local path of your assembly, which you can get form Assembly.GetExecutingAssembly().Location.

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Software Design Engineer
Developer Division Sustained Engineering
Microsoft

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Hashtable Item

3green11-Oct-04 5:32

3green

11-Oct-04 5:32

I know I am doing something silly, but I cant seem to access the Item property of a Hastable:

Hashtable myHash = new Hashtable();
myHash.Item;

Produces a build error
"System.Collections.Hashtable does not contain a definition for 'Item' "
But it sez in help that Item is a public property of Hashtable. Am using VS2003 Enterprise with Frameworks 1.1 SP1
Many thanks

Re: Hashtable Item

Brian Nottingham11-Oct-04 6:07

Brian Nottingham

11-Oct-04 6:07

In C# the "Item" property is accessed using indexer syntax. So instead you would write something like this.

Hashtable myHash = new Hashtable();
object value = myHash[key];

Re: Hashtable Item

Charlie Williams11-Oct-04 6:11

Charlie Williams

11-Oct-04 6:11

The Item property of HashTable is the indexer in C#. You access it using this syntax:

object val = myHash[objKey];

Charlie

if(!curlies){ return; }

Making function DragDrop to a treeNode

ee9903511-Oct-04 5:22

ee99035

11-Oct-04 5:22

Hi there!!

I´m having problems here. I want to make a drag and drop operation with a TreeNode of a treeview. I found that if I want to make the drag and drop operation with the TreeView it is possible. I just want to know if it is possible to make the same operation with only one node of the treeView.

Thanks for your help, Sérgio

Re: Making function DragDrop to a treeNode

Heath Stewart11-Oct-04 10:35

Heath Stewart

11-Oct-04 10:35

That's what the TreeView.ItemDrag event is for. It fires when you begin dragging a TreeNode. To handle dragging and dropping within the TreeView, you additionally handle the DragOver and DragDrop events at a minimum.

There is actually a good example of handling these events in the documentation for the TreeView.ItemDrag event in the .NET Framework SDK.

Note that unless you serialize your TreeNode it will not be available to other applications (or AppDomains - without marshaling in the source application).

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Software Design Engineer
Developer Division Sustained Engineering
Microsoft

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comobox.SelectedValue

webhay11-Oct-04 5:02

webhay

11-Oct-04 5:02

i assigne a number from Databaseto ValueMemeber in combobox.and i tryed to use it from ComboBox.SelectedValue but it return an object type but i need the number on this object for select a value in another Table but is not working.

Thnaks i need help please Frown | :(

Re: comobox.SelectedValue

Brett Slaski11-Oct-04 7:22

Brett Slaski

11-Oct-04 7:22

You need to cast the value.

E.g. int theInt = (int) ComboBox.selectedValue;

Re: comobox.SelectedValue

webhay11-Oct-04 7:32

webhay

11-Oct-04 7:32

Thanks to reply me but i did this casting but it give me this message
specified cast is not Valide

Thanks for your time please help me

Re: comobox.SelectedValue

Alex Korchemniy11-Oct-04 9:24

Alex Korchemniy

11-Oct-04 9:24

I'm not quite sure what you are trying to do but you can always use the debugger watch windows to determine the type of the object.

Re: comobox.SelectedValue

Brett Slaski11-Oct-04 10:33

Brett Slaski

11-Oct-04 10:33

How are you loading the combo?

Re: comobox.SelectedValue

webhay11-Oct-04 11:36

webhay

11-Oct-04 11:36

this my code:

private void cob_SelectedValueChanged(object sender, System.EventArgs e)
{
label1.Text = cbo.SelectedValue.ToString();
SqlConnection cnn = new SqlConnection();
cnn.ConnectionString = "workstation id=UNKNOW;packet size=4096;user id=sa;data source=UNKNOW;persist security info=False;initial catalog=TestDB;";
SqlCommand cmd = cnn.CreateCommand();
cmd.CommandType = CommandType.Text;
//int x = (int)cbo.SelectedValue;
cmd.CommandText = "Select * from Val Where Cat_ID = "+cbo.SelectedValue+"";
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataSet ds = new DataSet();
da.Fill(ds);
lst.DataSource = ds.Tables[0];
lst.DisplayMember = "Val_Name";
lst.ValueMember = "Cat_ID";
}

Thanks for your time ....

haytham

Re: comobox.SelectedValue

Anonymous11-Oct-04 15:50

Anonymous

11-Oct-04 15:50

I assume that this is working ok? Or is it Returning the object name? If not, how are you filling the combobox, databind or by item? SelectedValue is only used with databinding, a ValueMemeber must be set.
webhay wrote:
label1.Text = cbo.SelectedValue.ToString();

The following will not work because it will return the object name.
webhay wrote:
cmd.CommandText = "Select * from Val Where Cat_ID = "+cbo.SelectedValue+"";

Re: comobox.SelectedValue

webhay12-Oct-04 3:48

webhay

12-Oct-04 3:48

i filled the combobox with databind :

SqlConnection cnn = new SqlConnection();
cnn.ConnectionString = this.ConnStr;
SqlCommand cmd = cnn.CreateCommand();
cmd.CommandType = CommandType.Text;
cmd.CommandText = this.SelectCommand;
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataSet ds = new DataSet();
da.Fill(ds);
combobox.DataSource = ds.Tables[0];
combobox.DisplayMember = ds.Tables[0].Columns["Client_Name"].ToString();
combobox.ValueMember = ds.Tables[0].Columns["Client_ID"].ToString();

Re: comobox.SelectedValue

Brett Slaski12-Oct-04 4:05

Brett Slaski

12-Oct-04 4:05

webhay wrote:
combobox.DataSource = ds.Tables[0];
combobox.DisplayMember = ds.Tables[0].Columns["Client_Name"].ToString();
combobox.ValueMember = ds.Tables[0].Columns["Client_ID"].ToString();

You are not properly binding your combobox. Try this:
combobox.DataSource = ds;
combobox.DisplayMember = "TableName.Client_Name";
combobox.ValueMember = "TableName.Client_ID";

Note it is not recomended to use `ds.TableName' for the datasource.

Re: comobox.SelectedValue

webhay12-Oct-04 14:02

webhay

12-Oct-04 14:02

Thanks Brett Rose | [Rose]

it is working now you are so helpful
thanks for your time

and it is working in early binding too...
Big Grin | :-D

Regards
webhay

Re: comobox.SelectedValue

webhay12-Oct-04 14:05

webhay

12-Oct-04 14:05

Thanks Brett Rose | [Rose]

it is working fine now.you are so helpful....
Thanks for your time....

it is working in Erely binding tooo...

Smile | :)

;)

regards
webhay

Writing TreeView Contents To XML

enchantingdb11-Oct-04 3:15

enchantingdb

11-Oct-04 3:15

I am writing an RSS reader in C# and I'm trying to write the contents of a TreeView to an XML file. I have tried using XmlWriter and have managed to write simple tree structures but I get confused when it comes to dealing with complex tree structures such as those that have multiple folders and sub folders.

I have tried searching Code Project and the Net but haven't had much joy in finding a solution. I have only been using C# for a few months and my programming knowledge is fairly limited.

Is XmlWriter the best way to write out a TreeView? How would you go about going through each of the folders and writing the feeds within them?

If there is anything else that I need to include let me know.

Re: Writing TreeView Contents To XML

Alex Korchemniy11-Oct-04 9:17

Alex Korchemniy

11-Oct-04 9:17

Not a very popular article but you can try: http://www.thecodeproject.com/csharp/treeviewtoxml.asp

XmlWriter should be very easy. If you run into any problems try using the XmlDocument instead.

how to swap two tree nodes??

khchan11-Oct-04 1:35

khchan

11-Oct-04 1:35

hi..

let say i have 3 nodes in a TreeView
and i wanna swap the 2nd and the 3rd node..

here is my code segment.. but it doesn't work

TreeNode tempNode = treeView1.Nodes[1];

treeView1.Nodes[1] = treeView1.Nodes[2];
treeView1.Nodes[2] = tempNode;

the tree becomes a 5-node tree like this:
Node0
Node2
Node1
Node1
Node2
Confused | :confused:

Re: how to swap two tree nodes??

J4amieC11-Oct-04 3:03

J4amieC

11-Oct-04 3:03

you must remove and re-add the nodes as the setter in TreeView.Nodes[int] actually does an Insert.

<br />
TreeNode node1 = treeView1.Nodes[1];<br />
TreeNode node2 = treeView1.Nodes[2];<br />
treeView1.Nodes.Remove(node1);<br />
treeView1.Nodes.Remove(node2);<br />
treeView1.Nodes.Add(node2);<br />
treeView1.Nodes.Add(node1);<br />

How to make C# application run on win2000 and WinMe and Win98?

momer11-Oct-04 1:23

momer

11-Oct-04 1:23

It seems we have to install the whole .net framwork before run c# application on WinXP.But even if I install the .net framwork 1.1 package on Win2000,my C# application still cannt run on it.Since C# is better than VC++,why the application developed with it has such a unbearable restriction?
If we have to asked our users to install the .net framwork before run our application? or if there someother way to let our C# application run fluently on WinXP,Win2000,WinMe,Win98?
Thanks
momer

Re: How to make C# application run on win2000 and WinMe and Win98?

Anonymous11-Oct-04 1:36

Anonymous

11-Oct-04 1:36

Well, same situation here, different results:

Developing apps for the company under WinXP with VS.NET 2003 Enterprise Architect, Clients running Win2000 Prof with installed .NET-FW. No problems at all.

The FRAMEWORK should be available for Windows 98SE and higher, btw. Do not try and install the SDK on Win98.

But even that should work under W2K.

Maybe you have deployed your app for the 1.0 Framework and installed the 1.1 Framework on your client?

Installing the FW as admin should work. There may be a problem with your config, I have not encountered any probs with .NET so far.

You could just be "not quite lucky" Wink | ;)

Cheers
Sid

Re: How to make C# application run on win2000 and WinMe and Win98?

J4amieC11-Oct-04 2:53

J4amieC

11-Oct-04 2:53

momer wrote:
unbearable restriction?
If we have to asked our users to install the .net framwork before run our application?

Would it not have been wise to investigate the .NET platform before development?

Re: How to make C# application run on win2000 and WinMe and Win98?

Colin Angus Mackay11-Oct-04 3:12

Colin Angus Mackay

11-Oct-04 3:12

J4amieC wrote:
Would it not have been wise to investigate the .NET platform before development?

Eek! | :eek:

But that would have eaten in to valuable coding time. Gotta ship the project on time you know. Roll eyes | :rolleyes:

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