Re: Object reference not set to an instance of an object. - C# Discussion Boards

Re: Object reference not set to an instance of an object.

Guffa6-Jul-05 6:57

6-Jul-05 6:57

You are trying to use a reference that is null.

The most probable reason for this is that there is no table by that name in the data set.

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Re: Object reference not set to an instance of an object.

Member 20541716-Jul-05 7:13

Member 2054171

6-Jul-05 7:13

but it was working earlier and had no problems with it, suddenly this thig pops up, please help.

Thanks,

Re: Object reference not set to an instance of an object.

Guffa6-Jul-05 7:28

Guffa

6-Jul-05 7:28

That it was working before is not a guarantee that it is correct...

You have to examine how you populate the data set to find the reason why the table is missing or has a different name.

If the data set is supposed to contain a single table, you can access it using it's index (0) instead. Then the name does not matter.

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Re: Object reference not set to an instance of an object.

Member 20541716-Jul-05 7:37

Member 2054171

6-Jul-05 7:37

dgInv1.DataSource = objRightDataSet.Tables["GetInvGrid"].DefaultView;

it gives me error on the above line, and the ["GetInvGrid"] is not a table but a stored procedure.

I really appreciate your help thanks once again, I have a demo to show and I am stuck

Thanks,

Re: Object reference not set to an instance of an object.

Member 20541716-Jul-05 7:56

Member 2054171

6-Jul-05 7:56

some help

Re: Object reference not set to an instance of an object.

Dave Kreskowiak6-Jul-05 8:11

Dave Kreskowiak

6-Jul-05 8:11

Zindagi11@rediffmail.com wrote:
["GetInvGrid"] is not a table but a stored procedure.

This is your problem then. Did you actually execute that stored procedure? Did it return a table called "GetInvGrid"? If not, this is where your problem is! How do you fix it? Well, that's up to how you wrote your code that fills this table.

The reason you're getting this NullReference error is because you don't have a table in your dataset object that's called "GetInvGrid". Since you don't have that table, you can't get its .DefaultView property!

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Re: Object reference not set to an instance of an object.

Member 20541716-Jul-05 10:22

Member 2054171

6-Jul-05 10:22

well let me see what i can do, as if you just run the procedure alone it returns rows, so let me do it once again

Thanks,

Re: Object reference not set to an instance of an object.

Dave Kreskowiak6-Jul-05 11:51

Dave Kreskowiak

6-Jul-05 11:51

Yeah, in SQL Analyzer, if you EXEC the procedure, it returns rows. But, apparently, that's not what your coding is doing. From the code you posted, all your doing is trying to get at a table that doesn't exist in the DataSet object. When did you execute this procedure so it could return the rows?

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Re: Object reference not set to an instance of an object.

Guffa6-Jul-05 9:04

Guffa

6-Jul-05 9:04

As I said, you have to examine how you populate the data set to find the reason why the table is missing or has a different name.

The actual error is most likely not in the line where you get the error message, but in the code that populates the data set.

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windows application problem

snouto6-Jul-05 6:40

snouto

6-Jul-05 6:40

i need my application when windows starts my notify icon to load in the Deskbar as any program like norton antivirus or maccfee or even yahoo messenger.

Any help will be appreciated.

Miss With The Best And Die Like The Rest

Re: windows application problem

S. Senthil Kumar6-Jul-05 6:47

S. Senthil Kumar

6-Jul-05 6:47

Just add a shortcut to your application to the startup folder (C:\Documents and Settings\All Users\Start Menu\Programs\Startup).

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: windows application problem

LongRange.Shooter6-Jul-05 9:37

LongRange.Shooter

6-Jul-05 9:37

...or you can make your startup user-safe by adding a new key to the registry and set the value to your application (full path).

Add the key to:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run

create a key like myApp and make the value c:\{path}\myApp.exe

There are 10 kinds of people in the world.

Those that read binary...

...and those who don't.

network question

snouto6-Jul-05 6:34

snouto

6-Jul-05 6:34

hi all.
in my network application i accepted the request of the user to connect to my server by the following code

<br />
Tcplistener server = new TcpListener((Int32)1011));<br />
server.Connect();<br />
while(true)<br />
{<br />
client myclient = new Client(server.AcceptTcpClient());<br />
myclient.Connect();<br />
}<br />

The above code i accept the pending request of the user connection and i have his or her network stream by setting small line of code to initialize property for that

<br />
Public NetworkStream getthisstream<br />
{<br />
get<br />
{<br />
return myclient.Getstream();<br />
}<br />
}<br />

How can i get his or her Ipendpoint by knowing his networkstream to open new udpclient for him to transfer files through the network ? any help about that please

Miss With The Best And Die Like The Rest

Re: network question

S. Senthil Kumar6-Jul-05 6:52

S. Senthil Kumar

6-Jul-05 6:52

If you're looking for getting the IP address from the TcpClient object, you have to kludge your way through. Something like this.

IPEndPoint GetEndPoint(TcpClient client)
{
  Socket socket = (Socket)client.GetType().InvokeMember("Client",   System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance |   System.Reflection.BindingFlags.GetProperty, null, client, null);
  return socket.RemoteEndPoint;
}

The above snippet uses reflection to get the socket instance associated with the TcpClient, because, for some reason, the API designers decided to make it non-public.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Convert string to date type

zaboboa6-Jul-05 6:09

zaboboa

6-Jul-05 6:09

Is there a way to convert a string to date type?

Thank you

Re: Convert string to date type

S. Senthil Kumar6-Jul-05 6:26

S. Senthil Kumar

6-Jul-05 6:26

Does DateTime.Parse do the trick?

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Important question about Regular Expressions

Dario Solera6-Jul-05 4:47

Dario Solera

6-Jul-05 4:47

Hi all!

I've got a big problem with regular expression (I'm not very smart).

I have to select in a text all the c# multiline comments: /* ... */.

I use the following pattern:

\\/\\*.*\\*\\/

Note that I use the SingleLine option, so the dot means ALL chars.

that runs correcly only for the first occurence:

/* hello! */ is ok, but if there are two comments, like:

/* hello 1 */ some text here (with newlines) /* hello 2 */

the pattern selects all the text between the FIRST /* and the LAST */

I know the pattern is wrong, but I do not know any other statement...

Please help! Unsure | :~

Re: Important question about Regular Expressions

Guffa6-Jul-05 5:14

Guffa

6-Jul-05 5:14

Regular expressions are greedy by standard, meaning that the expression .* will try to match as many characters as possible. To make it match as few characters as possible you have to make it non-greedy (lazy) by adding a question mark after it: .*?

Use this pattern:

@"/\*.*?\*/"

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Re: Important question about Regular Expressions

Dario Solera6-Jul-05 5:49

Dario Solera

6-Jul-05 5:49

Thanks!!!!!!!!!

Rich Text Box printing

Taneth6-Jul-05 3:11

Taneth

6-Jul-05 3:11

One big difference I've found between the VB6 RTF and the C# RTF is that the VB6 one has a Print() function. I expected to find an even better one in C#, but there's nothing there. Is there a way to print from a C# RTF short of making my own and basically defeating the whole purpose of having an inbuilt one? I want to be able to specify by page, too, if possible.

Re: Rich Text Box printing

Dave Kreskowiak6-Jul-05 4:00

Dave Kreskowiak

6-Jul-05 4:00

A simple search on MSDN revealed How To Print the Content of a RichTextBox Control By Using Visual C# .NET[^].

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Re: Rich Text Box printing

Taneth6-Jul-05 17:26

Taneth

6-Jul-05 17:26

That actually worked suprisingly well. Thanks.

Propertygrid

Piovra_6-Jul-05 3:00

Piovra_

6-Jul-05 3:00

Is there a way to make a property in a propertygrid which opens up a form (sort of like browsing for an image), when a value is chosen from the form and the form closes i then get the chosen value in the property grid ?

Re: Propertygrid

LongRange.Shooter6-Jul-05 9:42

LongRange.Shooter

6-Jul-05 9:42

Yes.

Check out this article and the associated article:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/html/usingpropgrid.asp[^]

There are 10 kinds of people in the world.

Those that read binary...

...and those who don't.

DataTable.............

just4ulove76-Jul-05 2:45

just4ulove7

6-Jul-05 2:45

Hi,
I am new to Asp.net, I am using the below code on a link-click event to add a row in a datatable and then bind it to a datagrid. But only the last row is visible in the datatable. May be bcoz I am creating a new table on the click. How to get all the values persist on postback???

My code is :

DataTable dt = new DataTable("Requirements");

DataColumn dc= dt.Columns.Add("RequirementId");
DataColumn dc1= dt.Columns.Add("RequirementName");
DataRow row=dt.NewRow();
row["RequirementId"] = "R0001";
row["RequirementName"] = "New Requirement";
dt.Rows.Add(row);

Thanks
dgRequirements.DataSource = new DataView(dt);
dgRequirements.DataBind();

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