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Dear friends,
I am new to ADO.NET. I am able to use DataReader to display data. I failed to insert/update/delete the records. Does anyone know a good and working source for this topic?
Thanks a million $
Khang
PS: I tried out the following example but did not work!
Code Project/.NET - Simple ADO.NET Database Read, Insert, Update and Delete using C#. by John McTainsh
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To read,insert update data in an access db and in general with the oledbprovider there are 2 ways.
The easy way is to use the wizard in the visual studio when yu create a OledbDataadapter from the data tab in the toolbar, which creates a oledbdataadapter which can read data in a dataset, and after that if you change any data in the dataset, using the update method of the oledbdataadapter object you insert any new item and update any changes made in the dataset or in a specified table.This way is fast and doesn't need any special knowledge but allows only easy updates.
The second way is either to create a connection to the db and after that create some oledbCommand objects with sql syntax like
"INSERT INTO [tablename]([field1].[field2]...) VALUES([value1],[value2]...)"
to insert a new row,
"UPDATE [tablename] SET [field1]=[value1] WHERE [criteria]"
to update an existing row,
"DELETE FROM [tablename] WHERE [criteria]
and execute them directly, or create the oledbcommands and creat an oledbadapter object and set the properties updatecommand,insertcommand,deletecommand and selectcommand.This method with the oledbadapter requires the knowledge of using parameters with the commands.
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Thank you so much for the tips, Dimitris!
Khang
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i need alittle help.............how do i use this: System.Web.UI.HtmlControls.HtmlInputFile
in a windows application
Thank in advance
Da Intern
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you cannot use this control in a windows app, you should create your own using a textbox,a button and a System.Windows.Forms.Openfiledialogcontrol. It's easy to do it. Let's say tha name of the textbox is filetxt and of the button is mainbutton and of th openfiledialog is ofdcontrol.
write this code on the click event of the mainbutton [c#]
if (ofdcontrol.showdialog()==System.windows.forms.dialogresult.ok) filetxt.text=ofdcontrol.filename;
that's it
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Thanks for the help but i'm alittle lost. I want to recreate this this section of code for a windows application.
<code>protected System.Web.UI.HtmlControls.HtmlInputFile Upload;
private void Button1_Click(object sender, System.EventArgs e)
{
//It verifies if the archive exists
if (Upload.PostedFile != null)
{
//To create a PostedFile
HttpPostedFile File = Upload.PostedFile;
//Create byte Array with file len
byte[] Data = new Byte[File.ContentLength];
//force the control to load data in array
File.InputStream.Read(Data,0,File.ContentLength);
int i = 0;
//Dysplay array data in textbox
for (i=0;i<Data.Length;i++)
{
TextBox1.Text += Data[i].ToString();
}
//Create procedure parameter
object[] obj = new object[1];
obj[0] = Data;
//Execute the procedure with Microsoft.ApplicationBlocks.Data
//Simple procedure
/*CREATE PROCEDURE sp_img(@img image) AS
insert into tb_img values(@img)*/
//record data
SqlHelper.ExecuteNonQuery(connectionString,"sp_img",obj);
}
}</code>
Da Intern
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Hi all
I wrote a Windows service and I installed the same on two machines. I gotto start the first instance of the windows service, if and onlt if the second one isnt running. I tried implementing this using the ServiceProcess class. At the time of executing the ServiceController.Stop line, am getting an exception saying that "Unable to open the service at this machine".
Is there anyway to do this?
Thanks in advance
Karthik
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The issue is not with the installation. Its with the way I wanna access the same instance of the service running in different machine. Using System.ServiceController, I could able to access that service( via Windows forms application )by providing its machine name, service name, etc.
But the same code is throwing the exception while used in the On_Start method in Windows service code!!
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My OnStart method has the below check point,
if (myServiceController.CanStop==true)
{
Console.WriteLine(myServiceController.CanStop);
//IPAddress[] iPAddresss = Dns.GetHostByName(Dns.GetHostName()).AddressList;
IPHostEntry myHost = new IPHostEntry();
Console.WriteLine(Dns.GetHostName());
myServiceController.Stop();
}
else
{
Console.WriteLine("Cant Stop");
}
Thanks
Karthik
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i need help with a program in c#...can anyone out there help me please?!?
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NiNa03 wrote:
i need help with a program in c#...can anyone out there help me please?!?
Maybe... But we could help you faster if you post your specific problem, with details.
ORACLE One Real A$#h%le Called Lary Ellison
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Does anyone have a FourCC class wrapper available? I'm new to C# so I'm not sure if I'm doing something wrong. I'd basically like to have a number of predefined types that I can use within my class, I've currently tried the following:
<br />
namespace MyNamespace<br />
{<br />
public class MyClass<br />
{<br />
private static const FourCC TEST_FOURCC( 'T', 'E', 'S', 'T' );<br />
}<br />
}<br />
Where 'FourCC' is a struct I've defined which accepts four values. The compiler moans at this though (cannot specify constructor arguments in declaration).
As I'm new to C# is there something I've missed? It'd be great if I could just define them as an enum or uints (I've tried "private static uint TEST_FOURCC = 'TEST';" but it moans about too many characters in literal), I've also tried looking for a standard version in the framework but no luck.
Thanks,
n!
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nfactorial wrote:
private static const FourCC TEST_FOURCC( 'T', 'E', 'S', 'T' );
static const FourCC TEST_FOURCC = new FourCC( 'T', 'E', 'S', 'T' );
<a TITLE="See my user info" href=http:
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damn, so near and yet so far 
Thanks,
n!
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Hi!
I'm having some problems with flickering while resizing a Form!
I have a Form with two Panels and a Splitter. On each panel is a image drawn. Problem is when resizing the Form the images flicker like hell. Real annoying 
Anyway, I've tried to use the SetStyle (i.e. setting DoubleBuffering to true, UserPaint to true, and AllPaintingInWmPaint to true) method in the control class but that doesn't seem to work!! 
What do you recommend?
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I'm not sure that this would really be desirable for other reasons, but you could try the following:
Don't do any painting inside the normal paint handler. Instead, create a bitmap (which you'll need to resize along with the window size). Set that bitmap as the background image. Then, redraw the bitmap and call Invalidate() when the content changes. The rest of the time, the window should handle redrawing from the bitmap and avoid some of the flickering.
John
"We want to be alone when we hear too many words and we feel alone when it has been a while since anyone has spoken to us." Paul David Tripp -- War of Words
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Guys,
I've seen this type of question before but my search did not turn up anything.
Here is the C# API definition:
[DllImport"user32.dll",EntryPoint="SendMessage",ExactSpelling=false,SetLastError=true)]
public static extern int SendMessage(int hwnd,int wMsg,int wParam,int lParam);
All the places where I call this function I use simple integers. But now I have a spot where I want to call this function and for lParam I need to pass a pointer to a null-terminated string. How do I do that?
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For recieving a string:
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto)]
public struct STRINGBUFFER
{
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=512)]
public string szText;
}
[DllImport"user32.dll",EntryPoint="SendMessage", ExactSpelling=false,
SetLastError=true,<font color=red>CharSet=CharSet.Auto</font>)]
public static extern int SendMessage(<font color=red>IntPtr</font> hwnd,int wMsg,int wParam,<font color=red>out STRINGBUFFER lParam</font>);
For passing a string out:
[DllImport"user32.dll",EntryPoint="SendMessage",ExactSpelling=false,
SetLastError=true,<font color=red> CharSet=CharSet.Auto</font>)]
public static extern int SendMessage(<font color=red>IntPtr</font> hwnd,int wMsg,int wParam,<font color=red>text lParam</font>);
"Blessed are the peacemakers, for they shall be called sons of God." - Jesus
"You must be the change you wish to see in the world." - Mahatma Gandhi
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Thanks J,
I was sort of looking for a way to do it without having to change the import. I'm able to do what I need by using "..., String lParam)". But I am wondering if there was some way I could still use the "..., int lParam)" definition and do something special in the calling statment.
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albean wrote:
I was sort of looking for a way to do it without having to change the import.
Well, I don't know of a way, short of using pointers (which I think is more time-consuming). But you can have multiple defs for the same API with the same name. All you have to do is copy the original SendMessage each time and change the lParam parameter's data type.
"Blessed are the peacemakers, for they shall be called sons of God." - Jesus
"You must be the change you wish to see in the world." - Mahatma Gandhi
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I've got two applications, one written in C# and the other is WinBatch (don't ask). In regular C++ it was easy for the WinBatch app to simply PostMessage(..) to the C++ app and using a message map, I could set a function to get executed upon receiving the message.
In C# I'm having difficulty finding a way to receive and map the message received from a non-.Net based app.
Any insight would be greatly appreciated.
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I'm not sure what stage you are at but here is how I handle messages:
<br />
<br />
<br />
protected override void WndProc( ref Message m )<br />
{<br />
const int UWM_HERE_I_AM = 0x1234;<br />
<br />
switch( m.Msg )<br />
{ <br />
case UWM_HERE_I_AM:<br />
m.Result = OnHereIAm( m.WParam, m.LParam );<br />
return;<br />
}<br />
<br />
base.WndProc( ref m );<br />
}<br />
<br />
<br />
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I hadn't even thought of overriding the WndProc... doh!!
Thanks!!!
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I want to place a second Icon on the Title Region of a Form.
How?
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