Re: I wish myself a flicker free form - C# Discussion Boards

Re: Draw line between pictureboxes

Heath Stewart27-Dec-04 10:09

Heath Stewart

27-Dec-04 10:09

There's several things wrong I can see by scanning this over:

Put g.Dispose in a finally block, however...
DO NOT use CreateGraphics with owner-drawing; use the PaintEventArgs.Graphics that is passed to you in your OnPaint override. This could be responsible for quite a bit of the performance problem. Use the right ControlStyles bits in call to Control.SetStyle in your constructor to send all paint messages to OnPaint and allow for double-buffering. Be sure to read the documentation for the ControlStyles enumeration so that you use the right flags. In order to enable double-buffering you need to specify three different enumeration members. These are mentioned in the documentation for said enumeration.
When painting your controls - don't redraw the whole thing. You only need to re-draw what is passed to you in the PaintEventArgs.ClipRectangle. Depending on what you're drawing, the Graphics class members let you draw certain rectangles of an image only. If you redraw the entire image every time you will also notice performance pentalties, especially if transforms are applied to shrink the image, etc.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

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Re: Draw line between pictureboxes

ninja260529-Dec-04 0:38

ninja2605

29-Dec-04 0:38

Hello Heath,

Thanks for all the help. I have implemented point 1 and 2 but i am not able to implement point 3. I am calling Displaythumbnails() on panel paint event, it redraws all the images again, how do i implement cliprectangle? The application becomes slow when i scroll the panel

Thanks
Nitin

Re: Draw line between pictureboxes

Heath Stewart29-Dec-04 5:28

Heath Stewart

29-Dec-04 5:28

Use the methods of the Rectangle struct (of which ClipRectangle is defined) to see if your images and lines (artifacts) lie within the clipping rectangle, then redraw them. Do not redraw artifacts that lie outside of the clipping rectangle.

If you can, only redraw portions of the artifacts that are within the clipping rectangle.

There's many articles here on CodeProject about drawing. I suggest you try searching for them by using the search textbox at the top of every page directly underneath the logo.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

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Re: Draw line between pictureboxes

ninja260510-Jan-05 0:49

ninja2605

10-Jan-05 0:49

Thanks for all the help Heath. My previous problems are solved. Now i have a new one, its regarding Pen object. I am drawing lines of different colors based on a criteria. I have an If Else loop and when the panel paint event is called it selects the color specified in the else statement by default. Kinda overrides the color in the if statement. So all the lines turn out be blue. Here is the code:

foreach(Line l in Lines)
{
if(locallink!=null)
{
char charfileindex1='#';
int charfileindexlen1=locallink.Split(charfileindex1).Length;
string[] ss=new string[charfileindexlen1];
ss=locallink.Split(charfileindex1);
for(int i=0; i<charfileindexlen1; i++)
="" {
="" int="" index="ss[i].IndexOf(dragimage);
" if(checklinks(ss[i].tostring())=""> 0)
{
DrawAssocLine(l);
label4.Text="Red"+k.ToString();
k++;
}
else
{
DrawLine(l);
label5.Text="Blue"+m.ToString();
m++;
}

}

}

}
Region r = getRegionByLine(line,p);
thumbnailpanel.Invalidate(r);
thumbnailpanel.Update();
r.Dispose();

I wish myself a flicker free form

TyronX23-Dec-04 2:09

TyronX

23-Dec-04 2:09

My Form is flickering like hell, maybe because I have a lot of components in it (treeview, textboxes, listboxes, toolbar, menu, statusbar), and i couldn't find any solution for this. Double Buffering with SetStyle didn't work.

What can I do to reduce the flickering?

Re: I wish myself a flicker free form

Heath Stewart23-Dec-04 5:27

Heath Stewart

23-Dec-04 5:27

ControlStyles.DoubleBuffer - which must be combined with ControlStyles.AllPaintingInWmPaint and ControlStyles.UserPaint as the documentation states - is only effective when drawing your own forms. It will not simply change how GDI+ renders controls.

If you're getting flickering from including controls from the BCL on your form (all of which - at least for those you mentioned - encapsulates the native Common Controls) then you're machine is most likely the problem (or you're taxing the CPU by some pretty hefty code in your form's OnResize override or Resize event handler).

Check to make sure your monitor's refresh rate is as high as the monitor will support. If you're system doesn't have a lot of memory I recommend getting more memory.

Without knowing more it's hard to say, though. Do you have a lot of code in either the override or event handler I mentioned above? Is there anything else going on when your resizing or moving the form around? Do you have 20 instances of VS.NET open? Smile | :)

Basically, you should not be seeing any flickering (within reason; a Pentium I or II would be bad with, say, XP). Those controls you mentioned are actually the native controls that are wrapped by Windows Forms (so that controls are consistent with the platform, unlike Java AWT or Swing - though controls native to the framework have their advantages, too). If you're not seeing flickering on any of your native applications (like Windows Explorer, for example) then something else is the problem.

If you are doing a lot of work in your application when the form moves around or is resized then consider doing that work in a separate thread (if possible) so that the form can be repainted. If you need to update the UI from another thread, be sure to update the UI (i.e., makes calls on it) in the thread on which it was created by using the Control.Invoke method.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

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Re: I wish myself a flicker free form

TyronX23-Dec-04 6:47

TyronX

23-Dec-04 6:47

I don't think that the problem is dependent from my machine. I have a Athlon 2200+ CPU and 500 Megabytes RAM and it also happens without having the CPU loaded.
And it flickers as much as it does on my 1.5Ghz Notebook.

And yes I have a OnResize Event but commented out it's content. (it flickers on both ways)

I'll try to create a new Project and copy all forms from my original program to see if my program causes that flickering.

Thanks for investing so much (writing-)time for this Smile | :)

Re: I wish myself a flicker free form

Heath Stewart23-Dec-04 9:31

Heath Stewart

23-Dec-04 9:31

TyronX wrote:
And yes I have a OnResize Event but commented out it's content.

There is no OnResize event. If you override OnResize you must either comment the entire definition of the method (including the method itself) or call base.OnResize, passing the parameters you were given. When you override a method you are being called in place of the base class's implementation. Often times the base class implements something in that handler, besides firing the event.

So, if you are overriding it call base.OnResize or comment out the whole thing. If you're handling the Resize event than this isn't a problem (only with cancelable events like those defined as CancelEventHandler can you cancel whatever implementation the base event handler allows, like setting a property or losing focus for things like input validation).

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

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Re: I wish myself a flicker free form

TyronX23-Dec-04 10:23

TyronX

23-Dec-04 10:23

Oh. No, I meant the Resize Event. I wasn't sure wether both were the same

Connection to access database with C#.net

Robske23-Dec-04 1:41

Robske

23-Dec-04 1:41

Hi Everybody,

If got a problem:
When I run my program I get an error:

An unhandled exception of type 'System.Data.OleDb.OleDbException' occurred in system.data.dll

I tried a lot of other things but I still get this error.
Can anybody see what the problem is?

The code (of the class):

using System;
using System.Data;
using System.Data.OleDb;

namespace AISDBL
{
///

/// Summary description for Database.
///

public class Database
{
OleDbDataAdapter dataAdapter;
//SqlDataAdapter dataAdapter;
string connectionString;

public Database(string applicationPath)
{
connectionString = @"PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA SOURCE=./data/db.mdb;";
}

public DataSet getNieuws()
{

string SqlString = "select * from user";
DataSet dstResult= new DataSet();

dataAdapter = new OleDbDataAdapter(SqlString, connectionString);
dataAdapter.Fill(dstResult);

return dstResult;
}
}
}

Thanks

Re: Connection to access database with C#.net

leppie23-Dec-04 3:27

leppie

23-Dec-04 3:27

Robske wrote:
An unhandled exception of type 'System.Data.OleDb.OleDbException' occurred in system.data.dll

And what does the additional information of the exception say? The answer will be there, without it we cannot help you.

PS: You need to open the Connection, before calling Fill().

^{top secret
Download xacc-ide 0.0.3 now!
See some screenshots}

Re: Connection to access database with C#.net

Robske23-Dec-04 4:25

Robske

23-Dec-04 4:25

I Changed a few things but still the same error:

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.Data.OleDb.OleDbException: The component FROM contains a syntax error.
at System.Data.OleDb.OleDbCommand.ExecuteCommandTextErrorHandling(Int32 hr)
at System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method)
at System.Data.OleDb.OleDbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.OleDb.OleDbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.Common.DbDataAdapter.FillFromCommand(Object data, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet)
at AISDBL.Database.getNieuws() in d:\ontwikkelmap\visual studio projects\ais\aisdbl\database.cs:line 33
at AIS.FrmLogin.btnLogin_Click(Object sender, EventArgs e) in d:\ontwikkelmap\visual studio projects\ais\ais\load\frmlogin.cs:line 141
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

************** Loaded Assemblies **************
mscorlib
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/microsoft.net/framework/v1.1.4322/mscorlib.dll
----------------------------------------
AIS
Assembly Version: 1.0.1818.29878
Win32 Version: 1.0.1818.29878
CodeBase: file:///D:/Ontwikkelmap/Visual%20studio%20projects/AIS/AIS/bin/Debug/AIS.exe
----------------------------------------
System.Windows.Forms
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.windows.forms/1.0.5000.0__b77a5c561934e089/system.windows.forms.dll
----------------------------------------
System
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system/1.0.5000.0__b77a5c561934e089/system.dll
----------------------------------------
System.Drawing
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.drawing/1.0.5000.0__b03f5f7f11d50a3a/system.drawing.dll
----------------------------------------
System.Xml
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.xml/1.0.5000.0__b77a5c561934e089/system.xml.dll
----------------------------------------
AISDBL
Assembly Version: 1.0.1818.29877
Win32 Version: 1.0.1818.29877
CodeBase: file:///D:/Ontwikkelmap/Visual%20studio%20projects/AIS/AIS/bin/Debug/AISDBL.DLL
----------------------------------------
System.Data
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.data/1.0.5000.0__b77a5c561934e089/system.data.dll
----------------------------------------

************** JIT Debugging **************
To enable just in time (JIT) debugging, the config file for this
application or machine (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
<system.windows.forms jitdebugging="true">

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the machine
rather than being handled by this dialog.

I dont understand because it's simple code

Re: Connection to access database with C#.net

leppie23-Dec-04 4:42

leppie

23-Dec-04 4:42

Robske wrote:
************** Exception Text **************
System.Data.OleDb.OleDbException: The component FROM contains a syntax error.

So there is your problem. Could be wrong table name or the one u chose mite be a system table and it doesnt resolve, etc etc.

^{top secret
Download xacc-ide 0.0.3 now!
See some screenshots}

Re: Connection to access database with C#.net

Robske23-Dec-04 8:06

Robske

23-Dec-04 8:06

Jepz, ur right, it's the table name that causes the problem.

Re: Connection to access database with C#.net

Rob Graham23-Dec-04 8:56

Rob Graham

23-Dec-04 8:56

If you must use a table name (or field name) that is also a keyword for Access, try putting it in square brakets.
e.g: "Select * from [user]"

Why would anyone waste time arguing with an accountant about anything? Their sole function is to record what happenned, and any higher aspirations are mere delusions of grandeur. On the ladder of productive contributions they are the little rubber pads at the bottom that keep the thing from sliding out from under you. - Roger Wright

Re: Connection to access database with C#.net

Robske25-Dec-04 1:23

Robske

25-Dec-04 1:23

Ur right, that was the problem. user is a keyword!!
THANKS

Re: Connection to access database with C#.net

Heath Stewart23-Dec-04 5:32

Heath Stewart

23-Dec-04 5:32

Actually you don't. DataAdapter.Fill and DataAdapter.Update - or rather the default implementation of DbDataAdapter that extends DataAdapter and from which the other DataAdapter-derivatives directly derive) will open and close the connection if the connection was not open already.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Sustained Engineering
Microsoft

[My Articles] [My Blog]

Re: Connection to access database with C#.net

SeMartens23-Dec-04 3:32

SeMartens

23-Dec-04 3:32

Hi,

I think that the message within the exception would help a little bit more.

So what you have to do is to put your method getNieuws in a try-catch:

<br />
public DataSet getNieuws()<br />
{<br />
try {<br />
string SqlString = "select * from user";<br />
DataSet dstResult= new DataSet();<br />
<br />
dataAdapter = new OleDbDataAdapter(SqlString, connectionString); <br />
dataAdapter.Fill(dstResult);<br />
<br />
return dstResult; <br />
} catch (OleDbException ex) {<br />
Console.WriteLine(ex.Message)<br />
return null;<br />
}<br />
}<br />

Then look at your console what the exception writes back...

I think that would help a bit more

Sebastian Martens

Re: Connection to access database with C#.net

Robske23-Dec-04 4:27

Robske

23-Dec-04 4:27

I Changed a few things but still the same error:

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.Data.OleDb.OleDbException: The component FROM contains a syntax error.
at System.Data.OleDb.OleDbCommand.ExecuteCommandTextErrorHandling(Int32 hr)
at System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method)
at System.Data.OleDb.OleDbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.OleDb.OleDbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.Common.DbDataAdapter.FillFromCommand(Object data, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet)
at AISDBL.Database.getNieuws() in d:\ontwikkelmap\visual studio projects\ais\aisdbl\database.cs:line 33
at AIS.FrmLogin.btnLogin_Click(Object sender, EventArgs e) in d:\ontwikkelmap\visual studio projects\ais\ais\load\frmlogin.cs:line 141
at System.Windows.Forms.Control.onclick(EventArgs e)
at System.Windows.Forms.Button.onclick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

************** Loaded Assemblies **************
mscorlib
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/microsoft.net/framework/v1.1.4322/mscorlib.dll
----------------------------------------
AIS
Assembly Version: 1.0.1818.29878
Win32 Version: 1.0.1818.29878
CodeBase: file:///D:/Ontwikkelmap/Visual%20studio%20projects/AIS/AIS/bin/Debug/AIS.exe
----------------------------------------
System.Windows.Forms
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.windows.forms/1.0.5000.0__b77a5c561934e089/system.windows.forms.dll
----------------------------------------
System
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system/1.0.5000.0__b77a5c561934e089/system.dll
----------------------------------------
System.Drawing
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.drawing/1.0.5000.0__b03f5f7f11d50a3a/system.drawing.dll
----------------------------------------
System.Xml
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.xml/1.0.5000.0__b77a5c561934e089/system.xml.dll
----------------------------------------
AISDBL
Assembly Version: 1.0.1818.29877
Win32 Version: 1.0.1818.29877
CodeBase: file:///D:/Ontwikkelmap/Visual%20studio%20projects/AIS/AIS/bin/Debug/AISDBL.DLL
----------------------------------------
System.Data
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.data/1.0.5000.0__b77a5c561934e089/system.data.dll
----------------------------------------

************** JIT Debugging **************
To enable just in time (JIT) debugging, the config file for this
application or machine (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the machine
rather than being handled by this dialog.

I dont understand because it's simple code

Re: Connection to access database with C#.net

Rob Graham24-Dec-04 6:14

Rob Graham

24-Dec-04 6:14

'user' is a keyword. To use it (or any other access keyword) as a table or field name in a query you must surround it with square brackets.

try "select * from [user]"

Why would anyone waste time arguing with an accountant about anything? Their sole function is to record what happenned, and any higher aspirations are mere delusions of grandeur. On the ladder of productive contributions they are the little rubber pads at the bottom that keep the thing from sliding out from under you. - Roger Wright

undo implemention

ppp00123-Dec-04 0:34

ppp001

23-Dec-04 0:34

Hi all,

What is the mechanism for implementation of the "undo" and "redo"
functions in those applications, e.g. in a text editor ?
Are there any sample codes or reference in C# ?

Thanks

Re: undo implemention

benjymous23-Dec-04 1:07

benjymous

23-Dec-04 1:07

How you implement undo/redo is entirely dependant on the type of data you're working on.

For example, for a bitmap editor, an incredibly simple way (but somewhat naive) is to have two dynamic stacks - an undo stack and a redo stack.

Every time you change the bitmap, just place a copy of the image before the change onto the undo stack.

When the user selects to undo, push the current bitmap into the redo stack, and pop the top image off the undo stack.

Now if you're smart, you can store just the change in the stack rather than the whole image, which will use less resources

One thing to note is that undo/redo is far easier to implement if it's done from the start - trying to shoehorn undo/redo functionality into an existing application can be incredibly tricky

--
Help me! I'm turning into a grapefruit!
Phoenix Paint - back from DPaint's ashes!

Call external COM object, want to catch S_FALSE return code

ohadp22-Dec-04 21:07

ohadp

22-Dec-04 21:07

I'm calling an external COM object.
I want to be able to identify when it returns S_OK and when it returns S_FALSE.

Any other HREUSLT returned by the COM object is properly translated by the CLR to a COMException object. Nevertheless S_FALSE is treated as a success thus an exception isn't thrown.

How can I get this return code ?
I look at the registers and I can see EAX change according to S_OK/S_FALSE, but I can't access that data in any way.

Thanks

how to share class on vss?

montu337722-Dec-04 20:50

montu3377

22-Dec-04 20:50

Hi,

Can anybody told me that how to share a single class between 2 or more then 2 developers on Visual source safe.

thanks

montu3377

Re: how to share class on vss?

Alex Korchemniy22-Dec-04 22:42

Alex Korchemniy

22-Dec-04 22:42

The current version of VSS doesn't support multiple people having same file checked out. You'll have to take turns, wait for new version, or use a different source control application.

By the way this has nothing to do with C#

This posting is provided "AS IS" with no warranties, and confers no rights.

Alex Korchemniy

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