C# Discussion Boards - CodeProject

Martin3108810-Jun-09 4:21

10-Jun-09 4:21

Hi everyone,

I'm writing a little application and I've hit a bit of a problem.

part of the program uses the registry to store certain things. I have no problem writing or reading a key. But I need to be able to check the key exists, if it does do this, if not write the key.

Here's the code I'm currently using:

using Microsoft.Win32;<br />
RegistryKey MyRegKey = Registry.LocalMachine.OpenSubKey("software\\MyApp\\SaveData");<br />
            if (MyRegKey != null)<br />
            {<br />
                string OptCurrency = MyRegKey .GetValue("Currency").ToString();<br />
            }<br />
            else<br />
            {<br />
                RegistryKey CreateMyRegKey = Registry.LocalMachine.CreateSubKey("software\\MyApp\\SaveData");<br />
                CreateMyRegKey .SetValue("Currency", 0);<br />
                string OptCurrency = "0";<br />
            }<br />
MyRegKey.Close();

This is fine if the key exists, but doesn't recognise if it does not, and runs through the if rather than the else.

Any help would be greatly appreciated
Many thanks
Martin

Re: Checking a registry key exists

Henry Minute10-Jun-09 4:45

Henry Minute

10-Jun-09 4:45

I am not sure that I understand this.
Are you saying that if software\\MyApp\\SaveData doesn't exist, the if part of your code executes?

BTW: if you surround your code snippet with <pre></pre>, rather than <code></code>, it will allow you to retain the formatting and make it easier for others to read. (use the 'code block' widget, not the 'inline code' one).

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Re: Checking a registry key exists

Martin3108810-Jun-09 4:57

Martin31088

10-Jun-09 4:57

the other way around, if that key doesn't exist run the else part to create the key.

Re: Checking a registry key exists

Henry Minute10-Jun-09 5:07

Henry Minute

10-Jun-09 5:07

I realise that is what you intend to happen. But your OP indicated the reverse.

This is fine if the key exists, but doesn't recognise if it does not, and runs through the if rather than the else.

indicates to me that the if block gets executed regardless of whether the key exists or not.

Perhaps you might try rewording your question, to differentiate what you want to happen from what currently happens.

Re: Checking a registry key exists

Martin3108810-Jun-09 5:35

Martin31088

10-Jun-09 5:35

Currently
It does run through the if regardless of whether the key exists or not. The way the code is at the moment (some changes have been made to the previous post) the key will get created if it does not exist. I can then make a change in the options of my application and apply them which saves the change to their respective keys.

Then when I close the program and re-open it, the keys are reset back to the default because the code is running through the wrong part of my if statement and overwriting the key.

Intended
I would like it to be able to tell if the key exists, if it does not, create it, if it does, copy the value of each key into the defined global variables. So that program can use these values wherever necessary.

I'll post the altered code if you need.
I hope this clears it up.
Thanks

Re: Checking a registry key exists

Henry Minute10-Jun-09 6:16

Henry Minute

10-Jun-09 6:16

I do not use the registry any more, or very rarely, so I have had to go back and look at some of my old code.

The only obviously different things that I used to do is as below.

string myAppSaveDataSubKey = @"software\MyApp\SaveData"; <=== use a variable. saves having to keep typing it in and possible typos
using (RegistryKey MyRegKey = Registry.LocalMachine.OpenSubKey(myAppSaveDataSubKey)) <== using 'using' saves having to remember 'close'
{
    if (MyRegKey == null)  <=========== Check == null instead of != null
    {
        RegistryKey CreateMyRegKey = Registry.LocalMachine.CreateSubKey(myAppSaveDataSubKey);
        CreateMyRegKey.SetValue("Currency", 0);
        string OptCurrency = "0";
    }
    else
    {
        string OptCurrency = MyRegKey.GetValue("Currency").ToString(); <== you need to load OptCurrency anyway so don't 'else' it
    }
}

which used to work OK for me.

The only other thing you might consider is to use CreateSubKey instead of OpenSubKey. This has the advantage of creating the subkey if it doesn't exist, and simply opening it for writing if it does.

Hope some of this is useful. Smile | :)

Re: Checking a registry key exists

Martin3108810-Jun-09 6:28

Martin31088

10-Jun-09 6:28

Thanks for the suggestion, I'll have to look at it tomorrow.

I'll let you know how I get on.

Thanks alot for your support
Martin

Re: Checking a registry key exists

Martin3108810-Jun-09 23:57

Martin31088

10-Jun-09 23:57

I've finally sorted it!

I used some suggestions from your last post which helped. But I decided to tackle it from a different angle, eventually i came up with doing a valueCount

If (Count != 3)
{
create the keys
}
then copy values of each.

Works perfectly.

Thanks alot for your support Henry
Best regards
Martin

checkedlistbox - save checked items for future run

havejeet10-Jun-09 3:50

havejeet

10-Jun-09 3:50

Hi friends,

I have a checkedlistbox control on my windows form. Now when Application runs, every item is unchecked and user checks the items as per his choice. I want that - next time when user runs the application - checkedlistbox should be loaded with the same items checked. Meaning no need to recheck those values.

How do i do that?

many thanks,
Jeet

Re: checkedlistbox - save checked items for future run

Manas Bhardwaj10-Jun-09 3:51

Manas Bhardwaj

10-Jun-09 3:51

havejeet wrote:
How do i do that?

Store the checked items in a persistent store (database, file).
Read the stored values and load them when your form loads.

Manas Bhardwaj
Please remember to rate helpful or unhelpful answers, it lets us and people reading the forums know if our answers are any good.

Re: checkedlistbox - save checked items for future run

Rajesh R Subramanian10-Jun-09 4:01

Rajesh R Subramanian

10-Jun-09 4:01

You might use a file or the registry for storing your application settings.

It is a crappy thing, but it's life -^ Carlo Pallini

taking null instead of value

KIDYA10-Jun-09 3:01

KIDYA

10-Jun-09 3:01

Hello Experts!!

I am using following code inwhich instead of current value it takes null.I am using it at cell leave event of datagrid.

<pre>int ind = dataGridView1.CurrentRow.Index;
if (call == 1 ||call==2)
{
arr[x++] = (string)dataGridView1.Rows[ind].Cells[1].Value; //Error here
call++;
}

Re: taking null instead of value

Tom Deketelaere10-Jun-09 3:05

Tom Deketelaere

10-Jun-09 3:05

Let me turn my mind reader on...

trying to read error...
dense object detected...
error: can't read mind, shutting down now.

What error do you get?
What's the code supposed to do?
What does it do?
And what is your question?

Re: taking null instead of value

Colin Angus Mackay10-Jun-09 5:04

Colin Angus Mackay

10-Jun-09 5:04

KIDYA wrote:
current value

Define "current value" in the context of the code you have shown. There is nothing in the code called that. The nearest is "CurrentRow".

KIDYA wrote:
arr[x++] = (string)dataGridView1.Rows[ind].Cells[1].Value; //Error here

What sort of error? At a quick glance there are at least 8 possible points of failure on this line.

Man who stand on hill with mouth open wait long time for roast duck to drop in

Re: taking null instead of value

KIDYA11-Jun-09 18:35

KIDYA

11-Jun-09 18:35

Sorry there!!

i am using above error code in cellchange event of datagridview,i have three columns namely srno.,cust no.,name when i entered value into cust no. then in cell change event of custno value must be shown into arr[x++].but it cant show.
What to do???

SQL Database is not saved after data inserted!!

Zohair8310-Jun-09 2:25

Zohair83

10-Jun-09 2:25

Hi there,

I'm building a windows application using Visual Studio 2005.
1- I built the GUI and the database table needed.
2- I biult a SQL table with the fields needed.
3- I used the VS2005 wizards to establish connection and to create the dataset and table adapter.
4- I added a gridView to the form bound to the defalut data source enerated by VS.
5- I added a button with this code inside the click method:
/////////////////////////////////////////////////////////////////////
surveyTableAdapter.Insert(q1.ToString(), q2.ToString(), q3.ToString(), q4.ToString(),
q5.ToString(), q6.ToString(), q7.ToString(), q8.ToString(), name.Text, email.Text,
phone.Text, address.Text, post.Text, comments.Text, mailList.Checked.ToString());

this.surveyTableAdapter.Fill(this.surveyDataSet.Survey);//this is to populate the gridview upon a click

MessageBox.Show("Thank you for your participation in this servey.");
/////////////////////////////////////////////////////////////////////
6- The problem is that when I click the button I see the changes in the gridview, but when the program is re-executed, nothing is found in the table.In other words, changes are not saved.

7- I built a MS-Access database and connected it to the GUI, but the same thing happened.

I want to reiterate that i'm using the default cod and settings of the VS2005.

Can anybody help me in that?

Thanks in advance.

Zohair

Re: SQL Database is not saved after data inserted!!

EliottA10-Jun-09 2:57

EliottA

10-Jun-09 2:57

EW!!!

Here's some help..

Zohair83 wrote:
MessageBox.Show("Thank you for your participation in this servey.");

servey = survey.

Check out the CodeProject forum Guidelines[^]

Re: SQL Database is not saved after data inserted!!

Zohair8310-Jun-09 3:26

Zohair83

10-Jun-09 3:26

cum onn.. this has nothing to do with the problem, it's a mistype, man! Wink | ;)

Re: SQL Database is not saved after data inserted!!

DaveyM6910-Jun-09 3:33

DaveyM69

10-Jun-09 3:33

Have you called Update on the TableAdapter and AcceptChanges on the Table in the DataSet?

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)
Why are you using VB6? Do you hate yourself? (Christian Graus)

Re: SQL Database is not saved after data inserted!!

Zohair8310-Jun-09 6:05

Zohair83

10-Jun-09 6:05

NO, how are these set?

Thanks

Re: SQL Database is not saved after data inserted!!

DaveyM6910-Jun-09 6:11

DaveyM69

10-Jun-09 6:11

How to: Update Records in a Database[^]
DataTable.AcceptChanges[^]

Com Port [modified]

sahu.shikha10-Jun-09 2:09

sahu.shikha

10-Jun-09 2:09

hello
this is shikha, i m new in programming in Com Port, Actually my previous i did one project in which i have to receive/send SMS using COM1,
now the Device changed and it is supporting the Com3, Sending is working perfectly but unable to recive SMS using Port3.. here i m using Third party DLL. GSMCOMM DLL..just i m struck here,
one event is there "GsmComm.GsmCommunication.MessageReceivedEventArgs" is not firing, it should fired when message is recive BY the Port 3.. i m just unable to understand how to reslove the problem, i tried a lot, searched a lot....

 <br />
AT page Load I set Properties like.. <br />
1) Port Number 3;<br />
2) Baud Rate  9600;<br />
3)TimeOut 300;<br />
<br />
i am using GsmComm library, there is a Event which is fired when message Received.. Previously it is working Perfectly with "POrt1"..but now port is Changed Port 1 to port 3, so it's stop working, but still Sending SMS is Happening but Receiving is not happening??<br />
 <br />
"CommSetting.comm.MessageReceived += new MessageReceivedEventHandler(comm_MessageReceived);"<br />
<br />
<br />

plzzzzzzz help me!!!!!!!!!!!

modified on Wednesday, June 10, 2009 8:34 AM

Re: Com Port

Manas Bhardwaj10-Jun-09 2:23

Manas Bhardwaj

10-Jun-09 2:23

sahu.shikha wrote:
please Help me!!!!!!!!!!!!!

Do you think any one will have time to go through this lengthy code.
Better, pin point the problem so that people can help you. Rose | [Rose]

Manas Bhardwaj
Please remember to rate helpful or unhelpful answers, it lets us and people reading the forums know if our answers are any good.

Re: Com Port

Luc Pattyn10-Jun-09 2:33

Luc Pattyn

10-Jun-09 2:33

I don't read unformatted code; use the PRE tags (e.g. through the "code block" button under the edit box.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.

problem with logic

tasumisra10-Jun-09 1:28

tasumisra

10-Jun-09 1:28

hi all,
i was making a asp page with C# where i have display a data for a month or week for morning 8 am to 8 pm
for this shake am looping for whole month between 8am to 8 pm
can somebody suggest me something good as this logic looks like costly..

Thanks

vikas da

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