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See Refresh. This forces an immediately invalidation and redraw of the control. Of course things work a little differently with GTK so I'm not sure. Since this is primarily a Microsoft development site, you might check with other sites more appropriate for CLI apps on non-Microsoft systems (or using non-Microsoft APIs like GTK).
Also, be sure than when you're updating your controls from a separate thread you do so in the thread that created the control using InvokeRequired and Invoke. We've discussed this many times in this forum, and you can click "Search comments" above to find those discussions if you're interested in learning more.
Again, though, that's true on Windows platforms. Of course, with the way threads are handled this is probably true on any platform.
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Sustained Engineering
Microsoft
[My Articles]
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I have an application that is using a panel to hold a bitmap, for a skin. What I wanted to do was to load the app, then launch the function on form load. It takes a few seconds to load the form, but by the time the form has finaly loaded the update process on the application is already complete. I need my users to know that an update took, place using a progress bar.
What is the easiest way to check that the main form is loaded, prior to the function firing ?
D
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Seems like you are trying to do a something like a splash screen. If you application starts so fast maybe you can find a better way of notifing the user that an update took place.
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Basically just looking to delay my function from firing right away.
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A delay can be achieved with a Timer.
Set your timer interval to a specified amount of time (1000 = 1 second)
when your application starts, start the timer as well
In your timer TICK event, stop and dispose the timer, and execute your update function.
Jon G
www.Gizmocoder.com
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One way would be to hook an event handler to Application.Idle in the handler you have for Form.Load. The Idle event will be raised right after the Form is actually visible to the user. Remember to unhook your handler for Application.Idle in your handler for it.
You could also use BeginInvoke, which basically uses WM_POST to acheive a delayed call. So at the end of your Form.Load handler, you could do something like "BeginInvoke(new EventHandler(MyFunction));"
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Hi all,
In MAPI C# programming, I find that I can only send email to the
outlook express "out" folder, but can't program MAPI to ask it to send
the email directly. What should I do ?
Thanks
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That's what the Mail API does. An server application implements the API which you use. What the server application does is up to its implementation.
If you want to send email directly, consume the SMTP protocol. I recommend you click "Search comments" directly above this forum and search for "SMTP". We've discussed this several times, and I have posted code before to get the MX record of the mail server (which is the server that you connect to over port 25) at http://www.codeproject.com/aspnet/emailvalidator.asp?msg=305731#xx305731xx[^].
The SMTP protocol is actually a very simple protocol, BTW, and you can read more about it at http://www.ietf.org/rfc/rfc0821.txt[^].
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Sustained Engineering
Microsoft
[My Articles]
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Hello all.
I'm handling the keypress event of a data grid. I would like to know if the CapsLock key is pressed or not, but I haven't found nothing to do it.
Is possible this ? Can anyone help me ?
Thanks.
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Great. Thank you very much
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Topic cont'd... of type 'System.Data.Odbc.OdbcException' occurred in system.data.dll
Additional Information : System error
First of all hello, this is my first post, great site here, seems like their a lot of knowledgable people. Anyway I am just beginning to learn C#. I am creating a program for where I work for employees to login with a username and password and after successfully logging in they can clock in and clock out.
I am working on the login page first, known as form1 in my project. When the user clicks the "Login" button(known as button1) I would like it to load the next form where the user will be able to clock in and clock out. All the usernames and passwords are on a Access table. They will not be able to create their own but just use the preset ones. I want the program to check if what the user entered in as the username and password match whats on the table and if it does not, then it will display an error.
Here is a little snip of my code and I will point out which line the error points to:
public void button1_Click(object sender, System.EventArgs e) <br />
{ <br />
OdbcDataReader myReader; <br />
string myConnString = "DSN=MS Access Database;DefaultDir=C:\\DOCUMENTS AND SETTINGS\\OWNER\\MY DOCUMENTS;DriverId=25;DBQ=C:\\DOCUMENTS AND SETTINGS\\OWNER\\MY DOCUMENTS\\login.mdb;MaxBufferSize=2048;FIL=MS Access;PageTimeout=5;UID=admin"; <br />
string mySelectQuery = "SELECT Username, Password FROM tblLogin WHERE Username = " + txtUserName.Text; <br />
OdbcConnection myConnection = new OdbcConnection(myConnString); <br />
OdbcCommand myCommand = new OdbcCommand(mySelectQuery,myConnection); <br />
myConnection.Open(); <br />
[CODE]myReader = myCommand.ExecuteReader();[/CODE] <br />
while(myReader.IsDBNull(0)) <br />
{ <br />
lblErrorUser.Visible=true; <br />
}
The error points to the myReader = myCommand.ExecuteReader() line.
It does open the connection fine but when I click the Login button the error above comes up. If I comment in that line(using //) and the while loop, the program runs fine, well doesnt do what I want it to do but when I click the Login button it opens form2.
I believe it has something to do with the myReader variable. I have declared it as OdbcDataReader myReader where I have all my functions declared. I just noticed that their is a blue squiggly under the myReader where its declared.
Also, just want to mention that before this 'system error' I was recieving the following error: Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
and it was still pointing at the myReader = myCommand.ExecuteReader(); I did not change anything and all of a sudden I was recieving the system error. It still points at the myReader variable though.
Help is greatly appreciated. Thanks!
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The problem you're having is that Username is a string field, so you need to quote your field:
"SELECT Username, Password FROM tblLogin WHERE Username = '" + txtUIserName.Text + "'" BUT NEVER, EVER build SQL expressions using concatenation.
Sorry, but that isn't very smart at all. What if I pass "blah' AND 1=1; drop table tblLogin" from your TextBox? Bye bye login table. It's even worse that you store passwords in plain text. I could, instead, select all those and impersonate any user on your system. Can you say "lawsuits"?
Read http://www.codeproject.com/script/comments/forums.asp?msg=932507&forumid=1649&XtraIDs=1649&searchkw=parameterized&sd=7%2F8%2F2004&ed=10%2F6%2F2004#xx932507xx[^] for other problems and more things I could do using your SQL concatenation code.
ALWAYS use parameterized queries. Read the link above for an example, or the OleDbParameter class documentation in the .NET Framework SDK.
Also, your expression is very insecure besides not using parameterized queries. Don't select the password as part of the result set. Send the password and use it in the WHERE clause like so:
SELECT COUNT(*) FROM tblLogin WHERE Username = ? AND Password = ? In fact, even that's bad. You should never store passwords in plain text. Hash them using a one-way algorithm like MD5 or SHA1, both of which are supported by the .NET Framework base class libraries (see the MD5 and SHA1 class). Hash the password before sending it to the database server (and I assume this is actually for an ASP.NET application, which belongs in the ASP.NET forum but I'll continue anyway) or across the wire, then compare that to the hash you store in the Password field (using the same query as above).
In fact, even that's insecure. It's subject to replay attacks where someone sniffs your password and while they might not be able to unhash or decrypt it (at least with a given amount of time and resources), they could simply capture the packets, play them back, and you've been 0wned. Instead, store a salt, send it to the client, hash your password + the salt value and send it back to the server.
You should really read many of the good security Patterns and Practices books regarding .NET at http://msdn.microsoft.com/patterns[^].
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Sustained Engineering
Microsoft
[My Articles]
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We have a requirement to run a .Net app from a VB6 app. This is no real problem as I'm not doing the VB6 side but is it possible to create a registry entry with the install path of the .Net app at the time of install?
I could populate the reg entry at run time no problem, but this would mean the app must be run once before being called externally.
Alternatively is it possible to run an app atuomatically after an install, so the reg entry can be completed at run time.
Any suggestions welcome, Thanks
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This greatly depends on the setup technology you're using. If you're using an actually installation technology like Windows Installer, InstallShield setup, Wise setup, Nullsoft setup, or anything else then you can write a registry key with the path of the executable. If you're just doing XCOPY deployment (or otherwise dragging and dropping) then no.
You need to consult your installation builder documentation for this. This is not a C#-related question.
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Sustained Engineering
Microsoft
[My Articles]
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I'm trying to create a custom control in a dll. The class is inherited from the System.Windows.Forms.Panel class. On this new class i place a couple of labels and another panel, but when i add this control on a windows form, i only see the outline of the control but nothing on it. I tried the same thing with the System.Windows.Forms.Usercontrol class and that worked fine, but the moment i inherit from the panel class the trouble starts.
Can anyone tell me what i'm doing wrong?
Thanks,
Reinier.
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You may want to check the Z-Order of your controls
If your panel is in front of all the other controls, you will not see them.
Jon G
www.Gizmocoder.com
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Thanks for the reply. I tried setting the z-order, but still nothing happens. Do you have some other advise?
Thanks.
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Hi all, I am new to .NET and C# in general, so please pardon any stupid questions that I might ask, especially if the solution is glaringly obvious.
Ok, here goes:
I've been working through the visual studio walkthroughs to familiarize myself with the visual environment. Right now I am working on one where you create a dataset in xml that has three tables and their relationships and keys. The tables are customers, orders, and orderdetails. The walkthrough stops there. What I'm trying to do is display these tables in a DataGrid. I've created a sqlConnection, and some sqlDataAdapters. I am able to display the initial table - customers - in my DataGrid. My table is epandable, i.e. I can select a customer and it gives me the option of selecting the orders table. Now here is the problem: How do I populate the new table that appears?
I tried using the sqlDataAdapter.Fill(dataset) for each of the tables with the appropriate sqlDataAdapter for each table. Then I tried to use the DataGrid.Navigate, but that is uncharted territory for me and I am unsure how to continue. Any help is greatly appreciated.
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In case anyone else is having the same problem, I figured it out. Of course it was simple. Instead of using the sqlDataAdapter.Fill(dataset) like in the previous walkthroughs, I had to use sqlDataAdapter.Fill(dataset, "tableName")
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You can also set up the SqlDataAdapter.TableMappings so that "Table", "Table1", "Table2", etc. get mapped to your actual tables names. The generated table names are in the order of the tables in the result set if your expression, view, or stored proc were to return multiple result sets.
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Sustained Engineering
Microsoft
[My Articles]
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Hi,
Please help me to find a solution for change the windows service logon account and password through code
Thanks in advance
Regards
Subin
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If you want to do this at install time, use a ServiceInstaller and ServiceProcessInstaller which allow you to set the logon account when a service is installed using installutil.exe or the AssemblyInstaller in your own code.
If you want to do this at runtime, you'll need to P/Invoke ChangeServiceConfig like in the following example:
[DllImport("advapi32.dll", CharSet=CharSet.Auto)]
static extern bool ChangeServiceControl(
IntPtr hService,
uint dwServiceType,
uint dwStartType,
uint dwErrorControl,
string lpBinaryPathName,
string lpLoadOrderGroup,
ref uint lpdwTagId,
string lpDependencies,
string lpServiceStartName,
string lpPassword,
string lpDisplayName
);To get the hService handle, you'll need to also P/Invoke OpenService or CreateService. The ServiceController does most of what you need but not in this case, so you're probably better off writing your own class to handle that. I would recommend using the dispose pattern to make sure that any handle you open using OpenService or CreateService is closed using CloseServiceHandle.
Read Service Functions[^] for more information.
You can also visit http://pinvoke.net[^] for many managed signatures for unmanaged functions.
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Sustained Engineering
Microsoft
[My Articles]
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Hello,
Does exist on the codeproject website any article where a little pretty login function for PocketPC is developed??
thx
regards
pat
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http://www.codeproject.com/info/search.asp[^]
...or use the search box right below the logo on every page on CodeProject.
This posting is provided "AS IS" with no warranties, and confers no rights.
Software Design Engineer
Developer Division Sustained Engineering
Microsoft
[My Articles]
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