C# Discussion Boards - CodeProject

Alomgir Miah3-Jun-05 5:51

3-Jun-05 5:51

Hi
I have a datgrid and when I click the toolbar or menu which has a
save action, the last change is ignored. But if its a normal Button
everything works fine. Is there anyway to force the datagrid to save
the current record?

I tried CurrencyManager and EditCurrentEdit() but no luck.

Thanks
Alomgir

the key word "using" questiton?

jinzhecheng3-Jun-05 4:55

jinzhecheng

3-Jun-05 4:55

Hello, Friends,
// this is a piece of code from the book "Program Windows Form in C#"
// it uses keyword "using"

protected override void OnPaint(PaintEventArgs pe) {

Graphics g = pe.Graphics;
// after this , foreBush is disposed, so , how can it be used
// in the next statement.
// surprisingly. it works. Frown | :(

using( Brush foreBrush = new SolidBrush(this.ForeColor) )
using( Brush backBrush = new SolidBrush(this.BackColor) ) {
g.FillEllipse(foreBrush, this.ClientRectangle);
...

}

// Calling the base class OnPaint
base.OnPaint(pe);
}

Re: the key word "using" questiton?

MoustafaS3-Jun-05 5:03

MoustafaS

3-Jun-05 5:03

It's disposed after all the statements in the using clause is executed.

Re: the key word "using" questiton?

jinzhecheng3-Jun-05 5:12

jinzhecheng

3-Jun-05 5:12

// look at this:
using( Brush foreBrush = new SolidBrush(this.ForeColor) )
// here foreBrush is disposed eh?? how come it can still be used?
using( Brush backBrush = new SolidBrush(this.BackColor) )

Re: the key word "using" questiton?

S. Senthil Kumar3-Jun-05 5:23

S. Senthil Kumar

3-Jun-05 5:23

The using statement is translated by the compiler from

using(Brush foreBrush  = new SolidBrush(this.ForeColor))
{
...
}

Brush foreBrush = null;
try
{
   foreBrush = new SolidBrush(this.ForeColor);
   ...
}
finally
{
   if (foreBrush != null)
     ((IDisposable)foreBrush).Dispose();
}

foreBrush gets disposed in the finally block. Because you are using it within the block, it works. Your code will get translated into something like

Brush foreBrush = null;
try
{
   foreBrush = new SolidBrush(this.ForeColor);
   Brush backBrush = null;
   try
   {
       backBrush = new SolidBrush(this.BackColor);
       ...
   }
   finally
   {
      if (backBrush != null)
        ((IDisposable)backBrush).Dispose();
   }
}
finally
{
   if (foreBrush != null)
     ((IDisposable)foreBrush).Dispose();
}

Regards
Senthil
_____________________________
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Re: the key word "using" questiton?

DavidNohejl3-Jun-05 6:06

DavidNohejl

3-Jun-05 6:06

S. Senthil Kumar wrote:

Brush foreBrush = null;
try
{
foreBrush = new SolidBrush(this.ForeColor);
...
}
finally
{
if (foreBrush != null)
((IDisposable)foreBrush).Dispose();
}

which begs a question, what if foreBush does not implement IDisposable? It will simply crash ( throw exception) ?

David

Re: the key word "using" questiton?

J4amieC3-Jun-05 6:23

J4amieC

3-Jun-05 6:23

Hence why only those objects which implement IDisposible can be used within a using block.

In this case foreBrush is an instance of SolidBrush and that implements IDisposible

Re: the key word "using" questiton?

DavidNohejl3-Jun-05 6:39

DavidNohejl

3-Jun-05 6:39

I know. I just thought that it could be like

finally
{
IDisposable thing;
if ((thing = foreBrush as IDisposable) != null)
  thing.Dispose();
}

OK, it's better how it is.

David

Re: the key word "using" questiton?

S. Senthil Kumar3-Jun-05 7:22

S. Senthil Kumar

3-Jun-05 7:22

The code wouldn't compile if Brush didn't implement IDisposable. The compiler would complain that the type used in the "using" statement cannot be disposed, or something similar to that. So there's no question of a runtime crash.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: the key word "using" questiton?

DavidNohejl3-Jun-05 7:28

DavidNohejl

3-Jun-05 7:28

S. Senthil Kumar wrote:
The code wouldn't compile

That's exactly the answer I was looking for. Thanks.

David

Re: the key word "using" questiton?

jinzhecheng3-Jun-05 6:09

jinzhecheng

3-Jun-05 6:09

Hi , Senthil , does that mean, after foreBrush is disposed, if following code gona use it , then it will be constucted again ??

Re: the key word "using" questiton?

S. Senthil Kumar3-Jun-05 7:25

S. Senthil Kumar

3-Jun-05 7:25

No, it means that foreBrush will be disposed only at the end of its block. So

using (Brush foreBrush = new Brush())
   using (Brush backBrush = new Brush())
   {
   }// dispose backBrush
// dispose foreBrush as the block ends here.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: the key word "using" questiton?

Carsten Zeumer3-Jun-05 23:54

Carsten Zeumer

3-Jun-05 23:54

there is no ";" after the using( Brush foreBrush = new SolidBrush(this.ForeColor) ).
it behaves like the if clause. you can use it like this:

if (x == true)
  if (y==true)
   { 
    ... code in block ...
   }

or like this:

if (x == true)
{
  if (y==true)
   { 
    ... code in block ...
   }
}

if there would be a semicolon right after the using statement your assumption that the foreBrush should be disposed would be true.

/cadi

exec in C#

Bounz3-Jun-05 4:22

Bounz

3-Jun-05 4:22

How can I execute some command from my C# programm, as though I execute it from cmd.exe?
And how can I get the result of it?
So, I need execute "net view \\hostname" and get its output into a string variable..
Help, please..

--
Digitally yours, Bounz

Re: exec in C#

Judah Gabriel Himango3-Jun-05 4:31

Judah Gabriel Himango

3-Jun-05 4:31

Look at the System.Diagnostics.Process class. You can start a process and intercept its output to your own stream. You pass the name of the app into a ProcessStartInfo object just like you would pass the name of the app in the command window.

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: The Secular Left, the Religious Right, and Prejudice
Judah Himango

Re: exec in C#

Bounz3-Jun-05 4:46

Bounz

3-Jun-05 4:46

thanks, I'll try

--
Digitally yours, Bounz

how to make Gzip file in c#.net ???

Member 11968723-Jun-05 3:58

Member 1196872

3-Jun-05 3:58

hi ,

in my application i have so many file . and i have to make these files as Gzip file . is there anyone can help me by sending me the source code .
How to GZip many files including files ...

i use ICSharpCode.SharpZipLib.GZip;

Thanks

Re: how to make Gzip file in c#.net ???

Judah Gabriel Himango3-Jun-05 4:33

Judah Gabriel Himango

3-Jun-05 4:33

You might be better off asking this question on the icsharpcode website, as this is a 3rd party library. Additionally, a web search brings up some results such as this one[^].

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: The Secular Left, the Religious Right, and Prejudice
Judah Himango

Retrieve Method Name during Runtime

Seraphin3-Jun-05 3:45

Seraphin

3-Jun-05 3:45

I have a method, for ex:

<br />
public void test()<br />
{<br />
string MethodName = ????   <br />
MessageBox.Show(MethodName);<br />
}<br />

Is it possible to get method name information ?

Re: Retrieve Method Name during Runtime

S. Senthil Kumar3-Jun-05 4:05

S. Senthil Kumar

3-Jun-05 4:05

This piece of code

string methodName = MethodBase.GetCurrentMethod().Name;

does the trick. MethodBase is in the System.Reflection namespace.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

null object

george ivanov3-Jun-05 3:27

george ivanov

3-Jun-05 3:27

How to check if object is NULL:

object Location;<br />
Location = Reader.GetValue(0);<br />

I need an assert that object is not null here.

thanks

Re: null object

Marc Clifton3-Jun-05 3:31

Marc Clifton

3-Jun-05 3:31

george ivanov wrote:
I need an assert that object is not null here.

You mean, like:

Trace.Assert(Location != null, "Location is null.");

found in the System.Diagnostics namespace?

Marc

My website

Latest Articles:
Undo/Redo Buffer
Memento Design Pattern

Re: null object

Judah Gabriel Himango3-Jun-05 4:30

Judah Gabriel Himango

3-Jun-05 4:30

Maybe you mean checking in the database whether that value is null? That would be reader.IsDBNull(0)

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: The Secular Left, the Religious Right, and Prejudice
Judah Himango

Export Report To txt file

sevan3-Jun-05 3:21

sevan

3-Jun-05 3:21

how can i append this code to be able to export report to TXT file.

"ExportFormatType"
// Set the Export type, this can be:
// PDF, Excel, Word Doc, RTF Doc,
// HTML 3.2, HTML 4.0 or CrystalReport

but not txt ????

string exportFilePath = "c:\\Report1.txt";
// Create an instance of the untyped report object
ReportDocument oRpt = new ReportDocument();

// Load the report from disk
oRpt.Load(@"C:\Aloha\RPTFOH\Report_1.rpt");

// Set the options for saving the exported file to disk DiskFileDestinationOptions oDest = new DiskFileDestinationOptions();
oDest.DiskFileName = exportFilePath;

// Set the exporting information
ExportOptions oExport = oRpt.ExportOptions;

// Set the destination options
oExport.DestinationOptions = oDest;

// Set the location, this can be:
// DiskFile, ExchangeFolder, MicrosoftMail or NoDestination
oExport.ExportDestinationType = ExportDestinationType.DiskFile;

oExport.ExportFormatType = ExportFormatType.WordForWindows;

// Call the Export method to export the report
oRpt.Export();

Export to excel data from ultrawebgrid each row contain one worksheet

sunilmskr3-Jun-05 2:33

sunilmskr

3-Jun-05 2:33

Hi All
Export to excel data from ultrawebgrid rows, Each data row contain one worksheet in excel sheet like as
row1 data contain sheet1
row2 data contain sheet2
row3 data contain sheet3
this opertaion getting at a time on pressing one button.
we have pressing one button ultrawebgrid rows data to export excel sheet, In excel sheet each worksheet contain one grid row deatails, for example grid have 10 rows ,pressing any button, In excel sheet 10 worksheets will occure and each worksheet contain 1 row data of grid pls send me a solution for this example

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