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Hi Dan Thanks for your reply.
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Look at the following snippet of code. By pressing button1 invokes AddRow() method intending to add a row to the table (say Customers). When run it there won't be any erros but physically it hasn't added any row to the customers table. What's wrong with that. Anybody could suggest?
Thanks
***********************************************************************
public static void AddRow(DataTable myDataTable)
{
DataRow myNewDataRow = myDataTable.NewRow();
myNewDataRow["CustomerID"] = "T1Com";
myNewDataRow["CompanyName"]= "My Company Name";
myDataTable.Rows.Add(myNewDataRow);
myDataTable.AcceptChanges();
}
private void button2_Click(object sender, System.EventArgs e)
{
OleDbConnection conn = new OleDbConnection(@"provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Temp\orders.mdb;User ID=;Password=;");
string selectString = "SELECT CustomerID, CompanyName "+
"FROM Customers ";
OleDbCommand cmd = conn.CreateCommand();
cmd.CommandText = selectString;
OleDbDataAdapter dAdapt = new OleDbDataAdapter();
dAdapt.SelectCommand = cmd;
DataSet dSet = new DataSet();
conn.Open();
dAdapt.Fill(dSet,"Customers");
DataTable dTable = dSet.Tables["Customers"];
AddRow(dTable);
conn.Close();
}
************************************************************************
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Do you update your dataset with the new changes after you update the the "Customers" table?
Regards,
Polis
Can you practice what you teach?
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Thanks Polis. Not.
Because I feel AcceptChanges() method calls the UpDate() method.
However just now I added ** dAdapt.Update(dSet,"Customers"); ** statement into Button2_Click() function just after ** AddRow(dTable); **.
Now it looks like below.
AddRow(dTable);
dAdapt.Update(dSet,"Customers");
Still it is not writing to the table.
(Indeed I am using another way of inserting data to the table but wish to discuss and know why is it not working in this way.)
Thanks.
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The thing is that the actual table "Customers" has nothing to do with the dataTable dTable that you created. The dTable is just an object that you create in memory to hold the information of the "Customers" table. By adding a new row in it, it does not mean that you add a new row into your actual physically stored "Customers" table.
In your code, currently you add a new row into your dataTable object but you still update the dataAdapter with the "Customers" which is unchanged (since the new row was added in the dTable).
One way to achieve what I mean is:
1. Keep the addition of the new row into the dataTable dTable
2. Copy the dTable info back to the "customers" table
3. Update your dataset
Hope this helps
Regards,
Polis
Can you practice what you teach?
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Ur welcome 
Regards,
Polis
Can you practice what you teach?
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Hey!
I added an "AxWebBrowser" component to my form.
when I built the form everything was great, but pretty much useless.
so now I want to make my AxWebBrowser object navigate, so I added this method:
this.axWebBrowser1.Navigate("http://www.codeproject.com");
and I got the "InvalidActiveXStateException" Exception.
I really searched the web for a solution, but everything I found didn't work!
I don't underststand why it happens, and more than that, how to solve it.
can anyone help me with this???
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Do u know about any software can edit assembly files(.exe,.dll)?
Nothing
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Hi,
I looking for create dynamically some control in a form with the possibility of moving each control anywhere in the form.
I would like to store the position and store it to a xml files.
After create some config, I would like to restore a specific config.
My question is :
How can I moving each control create dynamicaly with the mouse ?
How can I retrieve the position of each control in the form ?
Best Regards
youssef
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In the class level :
Point p = new Point(this.button1.Location.X,this.button1.Location.Y);
In the mouse down event :
void form1_mousedown()
{
//Write some code to add the point p to the config file ,Ican't remember how right now.
this.p = new Point(-e.X,-e.Y);
}
In the mouse move event :
void form1_mousemove()
{
if (e.Button == MouseButtons.Left)
{
Point mousepos = Control.MousePosition;
mousepos.Offset(this.p.X,this.p.Y);
this.button1.Location = mousepos;
}
}
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How to suspend drawing operation of a form while a block of operations is done ?
For example I need to draw some things on the form and to move some controls so that the form doesn't repaint after each of them was moved.
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I'll give this a shot but a .NET guru might be able to point out a fatal flaw in my case, but here goes.
I know for sure that we could do something like this with streight WinAPI stuff but how will .NET controls handle it. Who knows.
Anyway the theory works like this. The message pump for your application is dispatching messages to all of your windows and controls. Just disable the pump, do your thing with the controls (in a non-gui thread) but be carefull not to use any blocking calls that rely on a message back (the pump is off now remember), then when you are all done, turn the pump back on and issue a WM_PAINT. I've done similar things in C++ using the WinAPI without hitches (usually). Also note that the manipilation of the controls is being done in a NON-GUI thread but I think that as long as you are carefull about what you are doing to those controls, you should be alright. Be quick though because I believe windows sends some kind of a heartbeat message every so often and if it detects that your pump is down, it'll pop up a dialog saying your app has stopped responding. Not sure the mechanism winsdows is using for this but i suspect it's using a WM_NCPAINT to detect this somehow.
Not sure how to turn the pump (message dispatcher) off in .NET application but I assume it's probably pretty easy.
*** NOTE
I assume that the controls you try to move about the form are issuing an Invalidate which causes the main form and the control to receive a WM_PAINT... Make sure you are not issuing and Invalidate or a refresh anywhere in your code that moves these around until you are all done.
Probably not too much help but it'll give you a starting point.
.NET GUI gurus, any ideas? Will this blow up in his face in .NET?
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Yes, I have done it like this.
Maybe there is a certain function in .NET that makes the same , but in an easier way.
Something like:
BeginUpdate();
.... some code here ...
EndUpdate();
Between these 2 tags the controls are not repainted.
Now I have made it through message filtering, i.e. I have a variable , which when set TRUE, paint messages are not allowed to be dispatched to controls contained in the form.
Works well.
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SuspendLayout();
... do your control moving, etc
ResumeLayout();
--
Help me! I'm turning into a grapefruit!
Buzzwords!
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SuspendLayout is a bullshit.
It doesn't work as it should. It do blocks some of the controls repainting, but allows others.
I have tried it many times - and it never worked as expected.
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Heh, fair enough.. it's worked exactly as I wanted in the places I've used it, anyway
Are you using custom controls? Perhaps those aren't too well designed for C# usage, or something 
--
Help me! I'm turning into a grapefruit!
Buzzwords!
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Actually I use standart controls in a usercontrol.
And this usercontrol is placed on a form.
Anyway - I read somewhere that SuspendLayout works only a few of the controls, because many of them has their own way of painting.
With standart controls, probably like buttons, labels - it may work.
With textboxes it doesn't work for sure (as it's controled by Windows).
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I need to serialize object of my class. I derives from a class which is not serializable. The questions:
1) Do I have to implement the ISerializable interfaace in my class?
2) Are enums serializable?? I have several enum fields in my class.
Thanks!
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#1 Just put the serializable attribute atop your class
#2 Yes they are and will be automatically, if used in your serializable class
the class you are deriving from not being serializable should not be a problem unless the class does some stuff that almost deliberlately makes it nonserializable. Give it a try, it should work flawlessly. Use the .NET serialization routines to save and restore your class, you'll find it works quite easily.
Use the .NET Binary serializer in your main code to save/restore these class objects.
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#1 Just put the serializable attribute atop your class
That won't work if the class he's extending is not serializable. From the MSDN[^]: "It is important to note that the Serializable attribute cannot be inherited. If you derive a new class from MyObject, the new class must be marked with the attribute as well, or it cannot be serialized. For example, when you attempt to serialize an instance of the class below, you will get a SerializationException informing you that the MyStuff type is not marked as serializable".
The only way around it is to use ISerializable
"I think I speak on behalf of everyone here when I say huh?" - Buffy
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hi
how i can load and display bitmap files in c#?
tanx®ards
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PictureBox pic = new PictureBox();<br />
Bitmab b = new Bitmap(@"Your path here");<br />
pic.Image = p;
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Hello gurus,
I would like to know, how I can add a browse for file or folders button in a PropertyGrid control?
Thanks for giving me a clue.
Best regards.
There is no spoon.
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Hey everyone!
I want to create a dialog window (SDI...) that will connect to the net to a certain address I'm writing inside my code. (so no one can change the address, only browse from the page they're getting).
Thanks!!!
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