Object reference problem in a windows application. - C# Discussion Boards

Re: how to Read folder contents

salmonraju12-Aug-07 21:01

salmonraju

12-Aug-07 21:01

Thank you ,It is working

crystal reports

monuSaini12-Aug-07 19:58

monuSaini

12-Aug-07 19:58

Hello Friends,

I had generated the crystal report.I want to change the connection string but I am unable to do so . Actually their are two database one is testing database and other is live database. So I need to change the connection string.

But I am unable to do so.

Regards,

rahul saini

Re: crystal reports

Imranlogi12-Aug-07 20:33

Imranlogi

12-Aug-07 20:33

Open your crystal report and on the left hand side you will find Field Explorer, under that you will find Database Fields, right click on that and click on Database Expert and the Database Expert Dialog box will open from there choose Project Data or Create New Connection, according to your need.
Thanks

Imran

Re: crystal reports

monuSaini12-Aug-07 20:49

monuSaini

12-Aug-07 20:49

Hello Imran,

If I choose new connection then all the feilds that i had drag from the previous table will delete.

Regards,

rahul saini

Re: crystal reports

Imranlogi12-Aug-07 21:18

Imranlogi

12-Aug-07 21:18

Ya the feilds will get deleted, do one thing what ever feilds you have dragged earlier, select all the feilds and copy it and when u create new report just paste all the feilds as it is, hope this may help.
Thanks

Imran

Re: crystal reports

monuSaini12-Aug-07 21:27

monuSaini

12-Aug-07 21:27

But Imran I had aroung 10 to 15 reports.
How is it possible to edit every time.

Is their any other sollution , through coding.

Regards,

rahul saini

Re: crystal reports

Imranlogi12-Aug-07 23:06

Imranlogi

12-Aug-07 23:06

I think u must have written some class where u have defined the connection string, change the connection string from there first, what ever new connection string you want. Now in report section u might be using Crystal Report Viewer, so in that Form Load write code like this, according to your table name and class name.
I hope this will help you.

private void CreateReport()
{
this.datcMarketData.getdatafrmdatabase();
JobMarketReport report = new JobMarketReport();
report.SetDataSource(datcMarketData.dSet);
crystalReportViewer1.ReportSource = report;
}

Thanks

Imran

Object reference problem in a windows application.

Janu_M12-Aug-07 19:23

Janu_M

12-Aug-07 19:23

Hi I am developing an windows application in C#.Net(2003).
My form has some textboxes, button and a datagrid. The functionality of the application is in a DLL.
The functionality is like this.
Enter input parameters in text boxes (one parameter belongs to time)
Click Start Button ==> the control goes to the DLL. based up on the time it has to perform the functionality.(suppose for example if we give 4 hours)

After completing a specific period (for example say 1hour) we have to enter a row in the data grid. THis action is done from the form.

For this i am using a timer in the form, on the elapsed time i am entering a row to the data grid by using a datatable.

Also notice one thing, I am using notify icon to show my application in system tray when it is minimized. If the addition of row is done when the form is in the minimized state, if i double click on the icon in the system tray then it is giving an exception "Object reference is not set" from the code in the notify icon Click. In this i am using a statement
this.ShowInTaskbar = true;

when the form is in normal state, adding a row to grid is happening correctly but the form is not responding after performing this action.

Any one please help me.
Thanks in Advance

Thanks and Regards
Ramu

C# DataGridView - Deleting a new Row

shubhabratam12-Aug-07 17:59

shubhabratam

12-Aug-07 17:59

Hi -
I try add a new row in DataGridView. But when I try to delete that it says "Uncommitted new row cannot be deleted". Does anyone know how to commit to add a new row? ANy help is appreciated.

Thanks
SHubho

Re: C# DataGridView - Deleting a new Row

Michael Sync12-Aug-07 18:09

Michael Sync

12-Aug-07 18:09

shubhabratam wrote:
I try add a new row in DataGridView. But when I try to delete that it says "Uncommitted new row cannot be deleted". Does anyone know how to commit to add a new row? ANy help is appreciated.

I think you may need to call Update() method or EndEdit() method of DataGridView..

For example ~

myDataGridView.EndEdit();

OR

myDataGridView.Update();

Hope it helps.

Thanks and Regards,
Michael Sync ( Blog: http://michaelsync.net)

If you want to thank me for my help, please vote my message by clicking one of numbers beside "Rate this message". Why vote? Plz Read it here. Thank you.

Re: C# DataGridView - Deleting a new Row

Imranlogi12-Aug-07 20:40

Imranlogi

12-Aug-07 20:40

I think u need to update the table. try this code, it is with respect to text boxes, accordingly you can try with datagrid.

string update = "Update JobEvaluationPlanData set Plan_id='" +
TxtPlanId.Text + "' ,Com_Fact='"
+ this.TxtCompFact.Text + "' ,Com_Fact_Def='"
+ this.TxtCompFactDef.Text + "' ,CF='"
+ this.TxtFactor.Text + "' where Plan_id= '" + this.TxtPlanId.Text + "'";

if (
this.TxtPlanId.Text != "" &&
this.TxtCompFact.Text != "" &&
this.TxtCompFactDef.Text != "" &&
this.TxtFactor.Text != "")
{
OleDbCommand command = new OleDbCommand(update, datcJobEvaluationPlanData.con);
datcJobEvaluationPlanData.dAdapter4.UpdateCommand = command;
//do the update
datcJobEvaluationPlanData.dAdapter4.UpdateCommand.ExecuteNonQuery();
MessageBox.Show("Record Updated...");
RefreshData();
}

Thanks

Imran

Re: C# DataGridView - Deleting a new Row

shubhabratam12-Aug-07 20:53

shubhabratam

12-Aug-07 20:53

I am using a DataGridView Control. I want to add a row which is just added to the Grid.

Re: C# DataGridView - Deleting a new Row

Imranlogi12-Aug-07 21:13

Imranlogi

12-Aug-07 21:13

I have used this code to add data to the table with respect to Text Boxes, u can try this for Datagrid with some changes.

string strInsert;
strInsert = "insert into JobEvaluationPlanData" +
"(Plan_Id, Com_Fact, Com_Fact_Def, CF)"
+ "values('" + this.TxtPlanId.Text + "','"
+ this.TxtCompFact.Text + "','" + this.TxtCompFactDef.Text + "','"
+ this.TxtFactor.Text + "')";

if (
this.TxtPlanId.Text != "" &&
this.TxtCompFact.Text != "" &&
this.TxtCompFactDef.Text != "" &&
this.TxtFactor.Text != "")
{

OleDbCommand command = new OleDbCommand(strInsert, datcJobEvaluationPlanData.con);
datcJobEvaluationPlanData.dAdapter4.InsertCommand = command;
//Do the Insert
datcJobEvaluationPlanData.dAdapter4.InsertCommand.ExecuteNonQuery();
MessageBox.Show("New Record Added...");
RefreshData();
TxtPlanId.ReadOnly = true;

}

Thanks

Imran

After passing file name in PrintQueue.AddJob(_,_,) folder is getting locked

gvisgr812-Aug-07 17:53

gvisgr8

12-Aug-07 17:53

Hello ,
I am having a problem in this issue,
I am trying to print a XPS document by passin job name and file path to

PrintQueue.AddJob(jobname,filename,false)

now job is getting queued and printed but the folder where the file is which i am printing is getting locked(i.e I am not able to delete the folder) even if i am deleting the file inside it.

Who am I?
Do you know me.... OMG | :OMG:

How to synchronize between GridView and DataTable?

Michael Sync12-Aug-07 17:42

Michael Sync

12-Aug-07 17:42

Hello,

There are one Editable Gridview in my winform. This GridView is binded with DataTable. After making some changes in GridView, I want to update the DataTable that is binded to GridView.

I have tried with Grid.Update() and DataTable.AcceptChanges();. but it doesn't work.

So, How to synchronize between GridView and DataTable? OR how can I update the DataTable from DataGrid?

Thanks in advance.

Thanks and Regards,
Michael Sync ( Blog: http://michaelsync.net)

covert string to particular pattern

Amjath Rahman12-Aug-07 17:40

Amjath Rahman

12-Aug-07 17:40

Hi All,

For example im having a string like this "0:30:1A:1E:55:2"
i want to convert this string to "00:30:1A:1E:55:02"

how can i do this.
right now im split the string using ':' and then find the length if its 1 then add 0 in front of it, it works fine for me....

but i think some simpler way must be there....
so plz guide me if am wrong

With Regards
Amjath

Re: covert string to particular pattern

Michael Sync12-Aug-07 18:05

Michael Sync

12-Aug-07 18:05

Amjath Rahman wrote:
add 0 in front of it

String.PadLeft Method[^]

<br />
Dim str As String<br />
Dim pad As Char<br />
str = "forty-two"<br />
pad = "."c<br />
Console.WriteLine(str.PadLeft(15, pad)) ' Displays "......forty-two".<br />
Console.WriteLine(str.PadLeft(2,  pad)) ' Displays "forty-two".

Creating a executable for a custom action

steve_rm12-Aug-07 12:56

steve_rm

12-Aug-07 12:56

Hello,

VS 2005

i have created a small windows application. I am wondering how can i make this into a independent program that can run as a custom action in a setup program.

Is it enough go into the bin directory and use the exe that is in there, and add that to the setup as the custom action.

The windows application uses a picture, is it best to have the picture embedded?

Many thanks for any suggestions.

Steve

Re: Creating a executable for a custom action

Jimmanuel13-Aug-07 7:46

Jimmanuel

13-Aug-07 7:46

Why did your post get downvoted?

Here[^] is an article that contains a good example of how to use your own code for a custom action.

porting c code and crc32

dfn12-Aug-07 9:42

dfn

12-Aug-07 9:42

Hi.
A few quick questions:
Does C# have any function that will compute crc32?
How can I port C code into C#? Do I have to rewrite it, or is there a quicker way?

Re: porting c code and crc32

Luc Pattyn12-Aug-07 10:03

Luc Pattyn

12-Aug-07 10:03

dfn wrote:
Does C# have any function that will compute crc32?

dfn wrote:
Do I have to rewrite it

Yes, that is the easiest way.
There are conversion tools that probably need some postprocessing, for a simple
code snippet it is not worth the trouble.

BTW there are some CRC articles on the CodeProject site...

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

this weeks tips:
- make Visual display line numbers: Tools/Options/TextEditor/...
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Re: porting c code and crc32

Ravi Bhavnani12-Aug-07 12:13

Ravi Bhavnani

12-Aug-07 12:13

dfn wrote:
Does C# have any function that will compute crc32?

No, but see this[^] article.

/ravi

This is your brain on Celcius
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ravib(at)ravib(dot)com

How to delete message from Sim card

Babubhai0712-Aug-07 9:29

Babubhai07

12-Aug-07 9:29

Hi Guys:

I have written an client server application in C sharp.My application is connected through GPRS USB modem.

My problem is currently all the messages store in the sim card (by default) and the sim card memory gets full after every 25 messages recieve
how can I programatically store the messages into computer memory and delete it from the modem .

thanks

reconnecting a client to socket server [modified]

gizmokaka12-Aug-07 7:58

gizmokaka

12-Aug-07 7:58

Hello to all,

I am using a socket server in c# I have created based on one from the code project.

it's an asynchronous server, creating a worker thread for client.

till now only tested with one client connected.

my problem is, when I disconnect a client and the reconnect, I get an exception of type

"An existing connection was forcibly closed by the remote host"

I need my application to operate in a manner that when the client reconnects, it's still

communicating with the server on same "IPEndPoint" and keep receiving messages from it,

as if no disconnection occurred.

P.S
When reconnecting the object still holds the same handle and port but ip is changed to
0.0.0.0
when in debug I am breaking on the spot where i get the exception.
The program stands there and values are LocalEndPoint = {192.168.2.100:5001}
on that breakpoint I dis and reconnect the device, and on the same break I get these
new values LocalEndPoint = {0.0.0.0:5001};

Please help me!!!!!!!!!!!

-- modified at 14:04 Sunday 12th August, 2007

.EXE file association

Harkamal Singh12-Aug-07 6:55

Harkamal Singh

12-Aug-07 6:55

As .txt opens with notepad as default, with what program .exe opens with?

I am aware, .exe is native to operating system. However i have a packaged program which is embedded into main program and is extracted to temp folder before execution..however with .tmp extention assigned. I can rename .tmp with .exe, I am just digging into windows internals and curious how this works.

I guess somefunction of rundll.dll is capable of executing .tmp files, but i am not quite informed about it.

Also, noticed that installshield and other installers copies executables as .tmp files and later executes them

thanks well in advance.

h.

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