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Hi Guys,
I always get stuck into thinking about the best way / most correct way of coding something.
I'm writting an application which uses a databasse.
One of table is used to store configuration information used (as example) by the configuration class/object.
Now at the moment, my database code including it's creation is all contained within a static class named Database.
My questions are:
1) Is having a static class for database routines a good idea? There is a potential for the application to be multi-threaded although each thread would most likely access different tables from the database.
2) Where is it best to code the rotine to load the configuration from the database?
I could have a method like Database.LoadConfig( Config config ) where an singleton instance of Config is passed to the Database --or-- I could have a method in the Config Class like Config.Load().
Any thoughts and comments appreciated.
Regards
Wayne Phipps
____________
Time is the greatest teacher... unfortunately, it kills all of its students
View my Blog
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Wayne Phipps wrote: 1) Is having a static class for database routines a good idea?
If you don't have too much interation with the database its fine. For larger applications you may wish to split up the interation into more logical divisions (maybe with a common base class)
Wayne Phipps wrote: There is a potential for the application to be multi-threaded although each thread would most likely access different tables from the database.
There are two ways I normally deal with a DAL. One is with the Enterprise Libraries. And the other is to do my own thing and for that the only shared information is a connection string that doesn't change. Each request to the database uses its own connection object (which is regarded as best practice) so there is no threading problems. If multiple things are accessing the database the database will handle it.
Wayne Phipps wrote: 2) Where is it best to code the rotine to load the configuration from the database?
I typically have a configuration class (a singleton class) that loads the information from the config file. All other code in the application can then access it.
If the configuration is large and complex I'll probably have a number of config classes to handle the various subsystems of the application. (Again, each will be a singleton - as all this is coming from a database, you may consider a common base for each of these an advantage)
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It often helpfull to have another persons perspective on the situation.
Many thanks for your comments.
They were indeed helpfull
Regards
Wayne Phipps
____________
Time is the greatest teacher... unfortunately, it kills all of its students
View my Blog
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Hello Friends,
I use this link to export datagrid values to excel sheet.
http://support.microsoft.com/kb/306023/EN-US/
and iam following this topic
Use Automation to Transfer an Array of Data to a Range on a Worksheet
The problem is , if the no of characters are more in the datagrid cell and if i make transfer to the excel sheet, then it throws error.When i debug , i found out if the characters in a datagrid cell exceed 910, then it throws error. If any of you, have faced a problem like this before,please share your thoughts.
Suresh.P.S
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HI
Are you Editing the datagrid ? What throwing the Exception datagrid or Excel sheet ?
<l>Thanks and Regards
Sandeep
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Hi,
I am not editing the datagrid. I am trying to export to excel.I am very sure, it is because of the no of characters presented in a cell.
The exception is COM Exception
"Exception from HRESULT: 0x800A03EC."
Suresh.P.S
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NO i don't think Suresh its because of it i just add near about 1000 char in one cell and also saved it succesfully !
Again you can you try again for some small data then go for bigger one
can you post the code ? so that i can see what you have done
I also had COM error that time it was due to Security issue  Its very difficult resovle COM error as errors are in number no description
<l>Thanks and Regards
Sandeep
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Hi,
use this link.i made my code from this link.
http://support.microsoft.com/kb/306023/EN-US/
and the following is my code
This is the windows application.when i truncate the data, it saves successfully, but when i increase the limit , then it throws the error.
// Start a new workbook in Excel.
excel = new Excel.Application();
books = (Excel.Workbooks)excel.Workbooks;
book = (Excel._Workbook)(books.Add(optionalValue));
sheets = (Excel.Sheets)book.Worksheets;
sheet = (Excel._Worksheet)(sheets.get_Item(1));
System.Data.DataView customizeGridView=(System.Data.DataView)CustomizeExportDataGrid.DataSource;
// Create an array for the headers and add it to cells A1:C1.
object[] headers=new object[customizeGridView.Table.Columns.Count];
//Read the column names from the view and add it as a column headers to excel sheet.
if(customizeGridView!=null)
{
for(int i=0;i < customizeGridView.Table.Columns.Count;i++)
{
headers[i]=customizeGridView.Table.Columns[i].ColumnName;
}
}
range = sheet.get_Range("A1", optionalValue);
if(customizeGridView.Table.Columns.Count > 0)
range = range.get_Resize(1,customizeGridView.Table.Columns.Count);
range.Value = headers;
range.EntireColumn.AutoFit();
font = range.Font;
font.Bold=true;
if(customizeGridView!=null)
{
// Create an array with 3 columns and 100 rowxs and add it to
// the worksheet starting at cell A2.
int rowcount=customizeGridView.Table.Rows.Count;
int ColumnCount=customizeGridView.Table.Columns.Count;
object[,] data = new Object[rowcount,ColumnCount];
int rowLoop=0;
int ColumnLoop=0;
//First the object values are copied and they are saved in to excel as a stretch to increase performance.
for(rowLoop=0;rowLoop <= rowcount-1;rowLoop++)
{
for(ColumnLoop=0;ColumnLoop <= ColumnCount-1;ColumnLoop++)
{
if(CustomizeExportDataGrid[rowLoop,ColumnLoop]==System.DBNull.Value)
data[rowLoop,ColumnLoop]=string.Empty;
else
{
data[rowLoop,ColumnLoop] = CustomizeExportDataGrid[rowLoop,ColumnLoop];
}
}
}
range = sheet.get_Range("A2", optionalValue);
range = range.get_Resize(rowcount,ColumnCount);
range.Value = data;
excel.DisplayAlerts=false;
book.SaveAs(filename, optionalValue, optionalValue,
optionalValue, optionalValue, optionalValue, Excel.XlSaveAsAccessMode.xlNoChange,
optionalValue, optionalValue, optionalValue, optionalValue);
Thanks,
Suresh.P.S
-- modified at 10:08 Thursday 8th February, 2007
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Hi All,
I have been trying to connect to a Btrieve database. For that I use Pervasive ODBC drivers ( Pervasive owns Btrieve now. ) I am able to connect to that database on my local machine. Btrieve database stores its data and all related stuff in flat files. Which I backed up from my production server, and was able to connect to this successfully. But when I tried to create a DSN on production server, follwing the same procedure, i got some error messages such status code: 4122, etc...
I am fed up of this database altogether now.
So, can anybody suggest me -
1. Is it possible to access Btrieve files directly from .Net ( ofcourse using ODBC drivers, but avoiding DSN errors)
2. Any way to create "link tables" (MS-Access) and then use that instead.
3. Accessing DSN on remote PC's in .Net directly without DSN on local machine ?
I am very fed-up of this thing. Also I need to find some solution to use that database. A quick solution will be most welcome. Even a complete solution is not there, please provide some ideas. (I dont know more about Btrieve, even how to find which version of Btrieve I am using.)
Thanks.
"A good programmer is someone who looks both ways before crossing a one-way street." -- Doug Linder
coolestCoder
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Hi,
I have the following problem:
I have a generic, which derives from a normal base class like this:
public class MyClass <T> : BaseClass
{
T m_Value;
public SetValue(T val)
{
// ...
}
public T GetValue(){ ... } ;
}
These classes are stored in a generic dictionary, which is instantiated like this:
dictionary<string, BaseClass> dic = new dictionary<string, BaseClass>();
At one point, I want to acess the SetValue Function, but I have to cast to the exact type, and typeof() / GetType doesn't works here.
What I try to do looks similar like this, but I haven't a solution yet;
MyClass< dic["Key"].GetType() > tC, tC2;
tC.SetValue((dic["Key"].GetType())dic["Key"].GetValue());
This isn't correct (i left out the instantiation) , I know, but I need to cast at runtime to the exact
generic type, stored at the position in the dictionary, for accessing the
generic, type specific Get/Set function.
Any comments ?
Thanks,
Florian
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I've search google exhaustively looking for some help with this and can't seem to find anything that has been productive. I have a Dynamic Link Library written in C++ which makes use of a callback:
LRESULT CALLBACK eventListener(HWND hWnd, UINT msg, WPARAM wP, LPARAM lP)
{
...
}
I'm trying to write a C# wrapper for this library and cannot seem to find the correct way to form the delegate to make use of the callback.
If anyone could point me in the right direction or knows of an example that might be helpful, it would be very much appreciated.
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Your function resembled a lot some of the win32 user32.dll
Look at www.pinvoke.net to get some ideas based on the functions of windows
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I've looked there, but unfortunately, have only seen the delegate definition without any examples on implementing it. The only reference I've found that comes close is a newsgroup post with someone having the same trouble. Of course, his question went unanswered as well. Luck of the Irish at it's best. lol
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I made a new thread cause i managed to solve my problem and thereby create a new one: I have a treeview with process names, there aren't any child nodes, the nodes' names are the process ID and i add them like so:
for (int i = 0; i < a.Length; i++)
{
treeView1.Nodes.Add(a[i].Id.ToString(), a[i].ProcessName);
}
Now, i have a timer that adds \ removes processes so i need to check the list if the process exists, and i managed to get the search thing working but i can't seem to remove them, here's the code:
a = Process.GetProcesses();
for (int i = 0; i < a.Length; i++)
{
bool found = false;
if (treeView1.Nodes.Find(a[i].Id.ToString(), true).Length == 0)
treeView1.Nodes.Add(a[i].Id.ToString(), a[i].ProcessName);
for (int m = 0; m < treeView1.Nodes.Count;m++ )
{
if (a[i].Id.ToString() == treeView1.Nodes[m].Name)
found = true;
}
if (found == false)
treeView1.Nodes.Remove(treeView1.Nodes[a[i].Id.ToString()]);
}
How can i fix it, or is it a more efficient way of doing it?
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a = Process.GetProcesses();
treeView1.Nodes.Clear();
foreach (Process p in a)
treeView1.Nodes.Add(p.Id.ToString(), p.ProcessName); /ravi
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Does anyone know how to add the raw HTML help project to a C# project so that they are compiled together.
I would like to be able to compile the help each time I build rather than use a pre-compiled one.
Many thanks
Ant.
I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Walliams (Little Britain)
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Confused 
Do you want a Web application project with Windows application project both work in hand ? or some thing different ?
<l>Thanks and Regards
Sandeep
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What I want is to be able to take my HTML Help project and ensure that that is built when I compile my C# project that requires that help.
I was just wondering how people have done this as I did not have a solution when I posted the message. In the mean time I have created a .bat file that is called on pre-build for the C# project and creates the help file that way.
It may not be perfect but it is functional and fit for purpose.
Thanks for your interest.
Ant.
I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Walliams (Little Britain)
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i have a string, i want to add "\u" for each 4 charachters of the string,
when i write a for loop, it refuses adding \u, i have to add @\u
for example: i have the strng 541236589632 i want to transfer it to \u5412\u3658\u9632
how can i do this on c# application
Thanks alot
Hamody
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I assuming you are having problems with the escape character I would define the string that you are adding as follows:
private const string mystring = @"\u";
This tells the compiler to take the string litterally and not use the slash as an escape character.
Ant.
I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Walliams (Little Britain)
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hello there, it doesnt solve the problem, i still have duble of "\\" string ....
it didnt solve the problem
how d u see???
Thanks alot
Hamody
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If you post your code and I will take a look at it then. Please also show input and output for your code and the desired output.
I am not 100% sure what you are having a problem with otherwise.
Ant.
I'm hard, yet soft.
I'm coloured, yet clear.
I'm fruity and sweet.
I'm jelly, what am I? Muse on it further, I shall return! - David Walliams (Little Britain)
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string ResultMessage="";
string varMessage;
varMessage = MMOUTBOUND_DGV.Rows[0].Cells[2].Value.ToString();
for (int k = 0; k <= varMessage.Length - 1; k++)
{
ResultMessage = ResultMessage + "\u" + varMessage.Substring(k, 4);
k = k + 3;
}
MessageBox.Show("ResultMessage ");
Thanks alot
Hamody
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First may i sugest in the for loop
for (int k = 0; k <= varMessage.Length - 1; k=k+4)
and eliminate the k=k=3;
As suggested before your code must be
ResultMessage = ResultMessage + @"\u" + varMessage.Substring(k, 4);
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helloz,
am not using an escape characters, i want to change from the ASCII code, so for example:
when i write in code:
messagebox.show("\u0064");
it will show me the character 'd' on the message that appear, so i can't use '\\u' instead of using '\u'
now what can i so to solve this problem 
Thanks alot
Hamody
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