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You can't just draw things over a panel an expect it to remain there. You draw on the screen, not on the panel element.
To make it work properly, you have to do the drawing from the paint event. Store everything you draw in an array list or something, and redraw it whenever paint is called.
Don't draw anything from the mouse move event, just add it to your list, then invalidate the panel so that it's redrawn.
---
b { font-weight: normal; }
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Hello everyone, I am doing this C# project and I have this problem. I am using the OleDb Database driver to open my csv and dbf files. I have noticed one problem with my connection string, it's that if the directory the file is in has a space in it like C:\D B\ it will not be able to read in the database for some reason. So if that is the directory the .csv or .dbf file is in, that means that C:\D B\ is the dataSource, and for some reason, it does not work. When I renamed the directory C:\DB\, the files were then read appropriately. Does anyone know how to fix this problem?
Sincerely,
The Major Rager
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You could try enclosing the path in quotes. However, I have tried the OleDbConnection class with an Access database (not .csv or .dbf) with spaces in the path, and I've had no trouble at all.
-- LuisR
Luis Alonso Ramos
Intelectix - Chihuahua, Mexico
Not much here: My CP Blog!
The amount of sleep the average person needs is five more minutes. -- Vikram A Punathambekar, Aug. 11, 2005
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Your code should look like this
string dbPath = @"C:\D B\" //escape
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Hello, thanks for replying. I already have it like that. It reads in the entire path, and it does connect to the datasource, but when it comes to reading in the Data with the datareader, it doesn't do it. But when I change the directory manually back to C:\DB and the dbPath = @"C:\DB\", it works.
Sincerely,
The Major Rager
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Why does this crash on invalid text? Otherwise it works, but if user input is invalid I end up in a MessageBox "house of mirrors"...
THanks a lot! -> Here's the code....
//////////////////////
////////////////////
void DrawComplexNumber1(Graphics g)
{
Pen p = c_xy.GetNextPen();
p.DashStyle = DashStyle.Dot;
c_xy.SetOrigin(xIndent + graphRect.Width/2, yIndent + graphRect.Y/2);
try
{
cmplxValue1.Real = Convert.ToDouble(textComplex_1Real.Text);
}
catch
{
MessageBox.Show("Error!");
}
try
{
cmplxValue1.Imaginary = Convert.ToDouble(textComplex_1Imaginary.Text);
}
catch
{
MessageBox.Show("Error!");
}
g.DrawLine(p, 250, 250, (float)(250 + (xIndent * cmplxValue1.Real)), (float)(250 - (yIndent * cmplxValue1.Imaginary)));
}
///////////////////
private void complex_1OK_Click_1(object sender, System.EventArgs e)
{
drawLine1 = !drawLine1;
Invalidate();
}
///////////////////////////
//In the Paint Handler
if(drawLine1)
DrawComplexNumber1(e.Graphics);
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Validate the data outside of the paint handler.
Now you are showing messageboxes from inside the paint handler, and when you klick away the messagebox it will cause a redraw of part of the screen, which most likely causes a new paint event in your application. This will put you into an infinite loop.
---
b { font-weight: normal; }
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How can I create and display a form to be topmost to the application only?
The requirements are :
* The form is the topmost window of the application.
* The form should not be topmost to other application and desktop. If the application is not the active application, the form window should not be displayed above the current application.
*The form should be in modeless status. The user can work with the application while the topmost form window is displayed.
A word in simple way, how to create a window like the "Find" dialog in the notepad.exe?
The topmost property in the form class can not work. If it is set to be true, the window will be topmost of everything.
Any expert has some idea? Or provide any clue to a windows API?
Thanks,
leo
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Create the dialog and display it using Show (instead of ShowDialog). Set it's Owner property to your main form.
-- LuisR
Luis Alonso Ramos
Intelectix - Chihuahua, Mexico
Not much here: My CP Blog!
The amount of sleep the average person needs is five more minutes. -- Vikram A Punathambekar, Aug. 11, 2005
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If its on mute, i want to unmute it, if its too quiet, i want to turn it up, if its too loud then i want to turn it down, etc.
Any ideas?
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I've never worked with multithreading before in any language.
I'm trying to figure out how to do the following:
I have a function, which generates unique values based on the current time.
It saves the data to a log file.
I have it set that when I click a button, it executes this code.
Rather, what I need to happen is to have it continually execute the function every 60 seconds until I reclick the same button.
I assume I need to use threads to do this. I've looked up several tutorials, but I really can't find an example to do this.
Can someone give me an idea?
Thanks.
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... this is the function I have. The first if clause needs to start a thread which executes the SaveWindow function every 60 seconds. The second needs to terminate the thread. I don't even know if this is the way threads work.
private void buttonScraperControl_Click(object sender, EventArgs e)
{
if (buttonScraperControl.Text == "Start")
{
buttonScraperControl.Text = "Stop";
SaveWindow(); // EXECUTE THIS FUNCTION EVERY 60 SECONDS
}
else if (buttonScraperControl.Text == "Stop")
{
buttonScraperControl.Text = "Start";
// STOP FROM EXECUTING EVERY 60 SECONDS
}
}
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I believe you can use the built in "Timer" control. http://www.c-sharpcorner.com/controls/timer.asp
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Will the timer stop execution of other parts of the program?
There are several other things that the user will be doing while
this bit of code is executing.
Is a timer really the correct solution?
Thanks!
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If you use a timer, it will be using a single thread. That means that the timer will only be triggered when your program is not busy doing anything else.
If you use a separate thread, it will be running even if your program is busy. The drawback is that the code has to be thread safe, meaning that if you are using any variables from both threads, you will have to take special precausions to make sure that only one thread at a time is using the variables.
---
b { font-weight: normal; }
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The System.Form.Timer or whatever it is, for some reason deson't lock up your GUI. Someone once explained why to me...
/\ |_ E X E GG
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I think a timer would be a good solution for your problem, cause it was made to execute code in regular intervals. Now you have to select the right timer for your needs.
If you use the System.Windows.Forms.Timer, your code will be executed in the UI thread. This prevents you from paying attention to threading issues, but if the code is time-consuming it will hang your GUI, cause the UI thread is busy.
If you use System.Timers.Timer or the System.Threading.Timer, your code will be executed by a worker thread. This won't affect your GUI, but you have to pay attention to threading issues e.g. change of GUI controls.
Take a look at this site[^] on MSDN for some more information.
www.troschuetz.de
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Hi,
I would like to create a winform application using c#, that looks kind of like Adobe Photoshop. That means the main window will have some small dockable windows inside the main window (those dockable windows can be minimized, closed, or maximized and docked). These windows will have other controls inside them.
I was wondering if you can give me some pointers on how to create windows like that, or can you send me links to some custom controls that I can use in my code that behave like those windows.
I'm still using visual studio.NET 2003, I might switch to VS.NET 2005 if there are controls like that in VS2005. Any idea, pointer, links, codes will be much appreciated.
Thanks
Ben
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What you are describing is MDI forms. Try looking here: http://www.codeproject.com/csharp/mdiformstutorial.asp
-- modified at 18:00 Thursday 13th October, 2005 (typo'd)
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Not really. I want the forms to be dockable too.
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Did you know that the Form class derives from Control? Think about that. A Form can be used just like a control. All it takes is a couple of modifications to it's properties. Check out this[^] article on MSDN for more information.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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I am working on a program to display "flash cards." Basically, the flash cards are 2 jpeg files, the front and the back. I'm using them to aid in learning a foreign language. Currently, I have this code:
private void btAdd_Click(object sender, EventArgs e)<br />
{<br />
hpClass blah = new hpClass();<br />
blah.addToArray( tbFrontFile.Text, tbBackFile.Text );<br />
blah.serializeArray( blah, "test.txt" );<br />
}<br />
[Serializable]<br />
public class hpClass<br />
{<br />
Stream[,] images;<br />
FileStream fsFront;<br />
FileStream fsBack;<br />
FileStream fsData;<br />
<br />
BinaryFormatter bfSerial;<br />
<br />
public void addToArray(string front, string back)<br />
{<br />
fsFront = new FileStream( front, FileMode.Open );<br />
fsBack = new FileStream( back, FileMode.Open );<br />
<br />
images = new Stream[1, 2]<br />
{<br />
{ fsFront, fsBack }<br />
};<br />
}<br />
<br />
public void serializeArray(object anything, string path)<br />
{<br />
fsData = new FileStream( path, FileMode.Create );<br />
bfSerial = new BinaryFormatter();<br />
bfSerial.Serialize( fsData, anything );<br />
fsData.Close();<br />
}<br />
}
The error I am getting is this:
Type 'System.IO.FileStream' in Assembly 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable.
And the bfSerial.Serialize line is the one generating the error. I'm using the C# 2005 Express Edition Beta. I'm completely lost  Any suggestions?
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Every member of your class needs to be serializable or marked with [NonSerialized]. You cannot serialize streams, so they'll need the [NonSerialized] attribute for sure. If you really want your object to contain the binary content of all those files, you should read the data into byte array members probably. However, that sounds clunky, especially if the jpg files are right there, all your object needs to remember is their names, right? Let me know if I'm not understanding your question right.
Matt Gerrans
-- modified at 17:26 Thursday 13th October, 2005
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