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That's right, you have to supply your own constructor if your going to do this. The TreeNode class doesn't have a constructor that understands the parameters you gave it, so you have to supply one that takes those 3 parameters in your MyTreeNode class code, but you don't need to recreate the constructors of the base class, TreeNode. Just add you own contructor.
public MyTreeNode( string drive, Int32 iconIndex, Int32 iconIndex );
The Int32's should be whatever type your trying to pass into your constructor...
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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ok, to recap:
I need to duplicate the base class's contructors in my inherited class's implementation if I use them in my inherited class.
If thats the case, and the TreeNode's constructor is suitable, then where does the following apply ?
Dave Kreskowiak wrote:
Since your extending the existing TreeNode class, all you have to do is supply your own constructor if one of the existing ones is not suitable.
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When you need override the base class constructors and do some extra work that they don't. Your constructor will get called, then you do your extra processing or whatever, like setting default data in your version of the class, then you call the base class constructor with the same arguments that were sent to you.
Now, if you need to get parameters that the base class constructors don't support, then you have to supply your own constructor with the parameters that you need. But, don't forget to call an appropriate base class constructor, so it can do the setup work it needs to do.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Guinness4Strength wrote:
I like to extend the TreeNode class through Inderitance to add a string property to the class.
If it's only adding a string property, why are you inheriting the TreeNode class at all? You can use TreeNode's Tag property to 'tag' (associate) any object with your node, including a string.
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Hi Gurus!
I got some troubles to fill Dataset...
I've added a Dataset.xsd file to my ASP.NET application. Then drag&drop some tables I want to retrieve data from. And after all I got such query
select code, package1.func(domain_cd, code, 'EN') as descr
from table1
The matter is that in PL/SQL developer this code works fine, but when I'm trying to run following code in C#
OracleDataAdapter da = new OracleDataAdapter(sql, con);
DatasetXSD= new DatasetXSD();
da.Fill(DatasetXSD, "table1");
an error occurs:
Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.
So I want to ask - do I need to set some relations in DatasetXSD during desing-time? And is it correct to use function in query to fill Dataset, or I should make it throught nested query? (I mean select code (select row1 from table2) as descr from table1)
xedom developers team
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I recently experienced the same problem, and I fixed it by setting up relationships between the table in your schema.xsd file. Seems like your relationships in the schema file need to match those in the database itself to resolve issues like this. Hope this helps
Frank
cout << "Have a nice day" << endl;
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ok, thanx. I have rebuild my query by adding some resaltions, so for now I am retrieving data from two tables, and I got inner join. MMy sql query looks like
select t1.code,
t2.name
from tab1 t1, tab2 t2 where t1.code=t2.code
Then I call DataAdapter.Fill(DatasetXSD);
no errors occured but DatasetXSD is empty, and when I run the same query in PL/SQL Developer everething works fine...
Maybe some one can tell me anoter way to fill Dataset from multiple tables correctly?
xedom developers team
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If you have relationships established between a couple (or more) tables, your Fill statement won't work because you're only filling one table ("table1"). Make sure you fill the whole DataSet.
Your SelectCommand can contain multiple SELECT statements, delimited by semi-colons (just like in SQL).
Make sure you add table mappings, though. A DataAdapter will, by default, map to tables "Table", "Table1", "Table2", ... "TableN". See the DataAdapter.TableMappings property for more details.
Microsoft MVP, Visual C#
My Articles
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Hi,
has anyone figured out how to get round the PrintToFile issue with .Net?
The PrinterSettings.PrintToFile property can only be set by the System.Windows.Forms.Printing.PrintDialog class. The Print to file option only appears on the System.Windows.Forms.Printing.PrintDialog when the System.Windows.Forms.Printing.PrintDialog.AllowPrintToFile property is set to true. For more information, see the KB article "'PrintDocument Class' Does Not Implement The PrintToFile Feature (820644)" on Microsoft TechNet, at Technet Article[^].
I really want to be able to print to a temporary file (using a pdf driver) for e-mailing.
Thanks in advance,
Gary
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I want to dublicate the textbox/richtextbox functions GetCharFromPosition, GetCharIndexFromPosition, GetLineFromCharIndex, and GetPositionFromCharIndex without API.
Unfortunately, I don't have a clue how to start. Can anyone give me some idea's?
Aaron Eldreth
TheCollective4.com
My Articles
While much is too strange to be believed,
Nothing is too strange to have happened.
- T. Hardy
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Either use the IL disassembler (ildasm.exe) from the .NET Framework SDK if you now how to read IL (Intermediate Language) or a good decompiler like .NET Reflector[^] to examine how those methods work. This is a handy approach to figuring out how code works. Some companies will obfuscate their code making it more difficult, but not impossible. Microsoft does not obfuscate their .NET FCL assemblies.
Microsoft MVP, Visual C#
My Articles
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Well, I decompiled the Textbox, Richtextbox, and TextboxBase from the .Net framework a while back. The problem was, the functions that I want use API to get the info. 
Aaron Eldreth
TheCollective4.com
My Articles
While much is too strange to be believed,
Nothing is too strange to have happened.
- T. Hardy
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That's right! Most of the .NET FCL classes are wrappers around API calls...
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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I visually generated control,
variable in code appears.
But I have class derived from that type,
(extend functionality to reuse),
by which I want to handle visual part,
I change type to derived, ...
but editor not see precise type and removes control from the form.
So,
How to connect variable to control in such case ?
Thanks
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I'm not sure I understand you (your question is very difficult to read, you might try elaborating a bit), but if you want to change the Type in your container (Form, UserControl, whatever), then make sure both the variable type declaration and the instantiated Type (in the InitializeComponent method) are the same, derived Type. Also make sure that that Type has been compiled and is either in the same project or a dependency project that has been referenced by your current project (when you right-click on the project and select Add Reference, select the project tab and add the project to make sure that a build dependency is established and that the build configuration (i.e., release, debug, whatever)is always in sync).
Microsoft MVP, Visual C#
My Articles
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???????????????????????????????????????????
This doesn't make any sense what-so-ever...
Are you saying that you created your own UserControl class, inheriting from an existing control?
Did you drop YOUR control on the form, or drop the base control that you inherited from? If you want to use YOUR version of the control, you'll have to add it to the Toolbox, then drag that onto your form, not the control you inherited from.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Witout new control creation - in a visual way,
I can not do it programmatically - to just add some small functions,
in inherited class?
but continue to edit all other properties - visually.
(control disappear from editor)
As extending Buttton in other languages, pure programmatically ?
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What your saying is VERY difficult to understand.
Are you saying that you want to set the properties of a control in a Properties Page like Visual Studio has in the bottom right corner of the screen? Is this control one that you wrote?
Are you trying to write your own extended Button class and have your extended properties show up in the Property Page?
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Im trying to make a specification here at work for how we should write our classes.
what i mean is for readabillity / make it as easy as possible to find the correct parts of your code.
some might suggest an apporach like this
class
{
//variables
//events
//constructor(s)
//propertis
//methods
//overrides
//interfance implementations
//nested casses
}
or
class
{
//variables
//events
//constructor(s)
//propertis (all propps , overriden propps , interface implemented propps)
//methods (all methods , overriden methods, interface implemented methods)
//nested casses
}
do you guys have any other suggestions?
what about regions ?
i tend to add regions to everything i do , but when im done it usually looks like crap with lots of folded blocks in it.
anyone seen any code that you think "it doesnt get any better than this" (layoutwise/readabillity that is) ??
//Roger
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I've once read the following structure in a book and use it since that time.
All parts are coded as a region and i try not to have more than two nested regions.
class
{
class variables
instance variables
construction, destruction
class methods
instance methods (further grouping depending on what the methods do)
interface implementations
}
www.troschuetz.de
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You've missed constants; I always put them up at the top.
"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar
The Second EuroCPian Event will be in Brussels on the 4th of September
Can't manage to P/Invoke that Win32 API in .NET? Why not do interop the wiki way!
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Hi all.
I'm trying to use WNetAddConnection2 to connect to a printerqueue on "lpt2:" or to some shared folder on a server on "u:" (or some other "free letter"). I have found several pieces of sample code on the net, and I have a working piece in managed C++, but in c# I get the error "Attempt to access invalid address". From what I understand the program does not recognise the local resource
Some code snippets:
Declarations:
[StructLayout(LayoutKind.Sequential)]
public class NETRESOURCE
{
public long dwScope = 0;
public long dwType = 0;
public long dwDisplayType = 0;
public long dwUsage = 0;
public string lpLocalName = null;
public string lpRemoteName = null;
public string lpComment = null;
public string lpProvider = null;
};
[DllImport("mpr.dll", EntryPoint="WNetAddConnection2")] public static extern int WNetAddConnection2A(NETRESOURCE lpNetResource, string lpPassword, string lpUserName, long dwFlags);
"Working code":
ntRec=new NETRESOURCE();
ntRec.lpRemoteName="\\\\SW\\cn=ADR-HP.ou=Printers.ou=HE.o=SW";
ntRec.dwType=RESOURCETYPE_PRINT;
ntRec.lpLocalName="lpt2:";
ntRec.lpProvider=null;
intRet=WNetAddConnection2A(ntRec, null,null, CONNECT_INTERACTIVE);
The c++ code that works looks like this:
String* pstrPrinter="\\\\SW\\cn=ADR-HP.ou=Printers.ou=HE.o=SW";
String* pstrPort="lpt2:";
TCHAR* pszName=(TCHAR*)(Marshal::StringToHGlobalAnsi(pstrPort)).ToPointer();
TCHAR* pszConn=(TCHAR*)(Marshal::StringToHGlobalAnsi(pstrPrinter)).ToPointer();
ntRec.lpRemoteName=pszConn;
ntRec.dwType=RESOURCETYPE_PRINT;
ntRec.lpLocalName=pszName;
ntRec.lpProvider=NULL;
dwRet=WNetAddConnection2(&ntRec, NULL,NULL, CONNECT_INTERACTIVE);
WNetCancelConnection works in C# thought, just using "lpt2:"
Any good ideas?
Thanks
/EnkelIk
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Hm. What can I say? Going over the code again, and replacing the long with enumerators in NETRESOURCE -I had some problem with these before but I can't quite remember what. Having done this it works like a charm.
Can't believe I have spent hours to solve this!
Sorry for taking your time 
Thanks
/EnkelIk
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DWORD values should be passed as either Integer, Int32, or UInt32 types in VB.ET and Long type in VB6.
VB6 Long = VB.NET Integer
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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I'm reading an Offic 2000 Excel spreadsheet through a c# app and I would like to know the limits of the populated cells, rather than itterating through until I read an empty cell (this is not a good mathod because a sheet can have gaps in it)
Is there a method that will return a single range covering the populated cells?
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