Re: Drawing on a form - C# Discussion Boards

Luc Pattyn1-Feb-07 1:12

1-Feb-07 1:12

Yes, that is what I did yesterday, as well as setting Format=Custom.
It worked, it moved from January 31 to February 28; when clicking down it went
back to January 28 (both when still "open", the result field went January 2007 ->
February 2007 -> January 2007.

I have now tried in on .NET 2.0 and once again it works fine.
I did not modify the system time (dont like to do that), but I used the arrow keys to
change the date picked by one day, and the arrow buttons to move it by one moth.
The keys make it move February 1 -> January 31 etc and the arrow buttons react as said before.

So everything seems OK to me.

If intersted, send me an e-mail and I attach my project to the reply.

Smile | :)

Luc Pattyn

Pratik Vasant Shah1-Feb-07 2:03

Pratik Vasant Shah

1-Feb-07 2:03

Hi,

Further to your reply, please find a sample project attached
However, to bring to your notice, I dont have .Net 1.1 with SP1, In fact I have .Net 2.0.

Also, this error is reproduced only if your PC(System) Date is 31st January 2007.

Apart from that, there is a property called "CustomFormat" of datetimePicker Control which has to set to "MMMM yyy"

Since CodeProject does not have any attachment faciliy, and neither I have your email address, I am attaching the code of the ".Designer.cs" in this reply itself. Just create a new project and paste this below code in the
newly created Form of the project

Regards

Pratik Shah

Code
Code in DateTimePicker.Designer.cs
namespace DateTimePicker
{
partial class DateTimePicker
{
///

/// Required designer variable.
///

private System.ComponentModel.IContainer components = null;

///

/// Clean up any resources being used.
///

/// <param name="disposing" />true if managed resources should be disposed; otherwise, false.
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}

#region Windows Form Designer generated code

///

/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
///

private void InitializeComponent()
{
this.dateTimePicker1 = new System.Windows.Forms.DateTimePicker();
this.SuspendLayout();
//
// dateTimePicker1
//
this.dateTimePicker1.CustomFormat = "MMMM yyy";
this.dateTimePicker1.Format = System.Windows.Forms.DateTimePickerFormat.Custom;
this.dateTimePicker1.Location = new System.Drawing.Point(34, 12);
this.dateTimePicker1.Name = "dateTimePicker1";
this.dateTimePicker1.ShowUpDown = true;
this.dateTimePicker1.Size = new System.Drawing.Size(105, 20);
this.dateTimePicker1.TabIndex = 0;
//
// DateTimePicker
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(176, 87);
this.Controls.Add(this.dateTimePicker1);
this.Name = "DateTimePicker";
this.Text = "Form1";
this.ResumeLayout(false);

}

#endregion

private System.Windows.Forms.DateTimePicker dateTimePicker1;
}
}

Luc Pattyn1-Feb-07 2:16

1-Feb-07 2:16

With the "email" option (to the right of "reply") you can send me an email (without attachment).
Upon that, I can reply with attachment using my regular mail tools.

Smile | :)

Luc Pattyn

Luc Pattyn1-Feb-07 5:13

1-Feb-07 5:13

Hi,

you are absolutely right, when ShowUpDown=true the look and behavior change,
and you can get an ArgumentOutOfRangeException; seems the DateTimePicker gets
initialized to DateTime.Now with all details (year, month, day, h, m, s) even
when only parts of it are used. And adding 1 month to 31-JAN throws.
(This is not a big surprise, there is no such thing as a partial DateTime,
and when you were to modify ShowUpDown to false again, you would hope to see
the current date, not something else...)

Obviously the workaround must be to modify the DateTimePicker.Value at LOAD time,
i.e. before the buttons can be activated. I would suggest:
myPicker.Value=new DateTime(DateTime.Now.Year, DateTime.Now.Month, 1);

Smile | :)

Luc Pattyn

Drawing on a form

Da_Bigg_Z31-Jan-07 5:35

Da_Bigg_Z

31-Jan-07 5:35

Hello everyone,

I have made a basic windows form that I can draw on. The problem is that
when I resize the form the drawing disappears or gets clipped accordingly

how can I draw on the form and maintain the drawing even if I resize the form?

clear steps in a tutorial manner would be highly appreciated

thanks everybody for being there

Colin Angus Mackay31-Jan-07 5:51

Colin Angus Mackay

31-Jan-07 5:51

You need to redraw it each time the window is damaged. You do this by overriding the OnPaint() method.

Upcoming events:
* Glasgow Geek Dinner (5th March)
* Glasgow: Tell us what you want to see in 2007

My: Website | Blog | Photos

Da_Bigg_Z31-Jan-07 6:01

Da_Bigg_Z

31-Jan-07 6:01

well sounds good but the code for drawing on the form is kept inside the MouseMove Event whenever it is fired it checks to see whether the left mouse button is pressed and then it draws according to the mouse movement.

The drawing is using the graphics object, let's say of a form or a panel on the form. How will the OnPaint method recognize the drawing?

I mean I get your point and it seems that it will work but can you explain a bit more?

RugbyLeague31-Jan-07 6:14

RugbyLeague

31-Jan-07 6:14

You have to track all the drawing you do then when OnPaint fires recreate the drawing - if the form has changed size you can then rescale the drawing.

Luc Pattyn31-Jan-07 8:21

31-Jan-07 8:21

You really need an internal representation of your drawing.
You should build it up with mouse and/or keyboard events
and paint it in the OnPaint handler.
You then can also add file open and file save operations.

OnPaint is called automatically whenever there is a good reason to repaint the form or panel,
such as:
- form/panel became visible again (an overlapping form has been moved or closed)
- form gets resized (including form maximize, restore from minimize, restore from maximize)
- probably many more
- or you explicitly causing a repaint by calling Invalidate(), e.g. after you loaded a new file.

Smile | :)

Luc Pattyn

Which user has the file open?

Ennis Ray Lynch, Jr.31-Jan-07 9:59

Ennis Ray Lynch, Jr.

31-Jan-07 9:59

Call Invalidate and pass it the region to be redrawn whenever you cause an event that needs to be drawn.

File Not Found

RugbyLeague31-Jan-07 5:01

RugbyLeague

31-Jan-07 5:01

How in C# when I try to write over a file which another user has open do I find out their username so I can show it in a MessageBox?

TIA.

Re: Which user has the file open?

ed^nrgc31-Jan-07 6:49

ed^nrgc

31-Jan-07 6:49

You have 2 people editing a file at the same time? WTF | :WTF:

Re: Which user has the file open?

RugbyLeague1-Feb-07 23:47

RugbyLeague

1-Feb-07 23:47

No, the application creates a PDF file - occasionally somebody might want to recreate the PDF file and even more occasionally somebody might already have the PDF file open - the chances of it happening are slim but if it does happen I would like to be able to display the username of the user who has the file open.

Re: Which user has the file open?

ed^nrgc2-Feb-07 2:29

ed^nrgc

2-Feb-07 2:29

Why not just have a policy where users save the PDF to their local machine before opening? If they are viewing it via the web, send it via a stream, instead of the actual file.

System call in .NET

BehemotCat31-Jan-07 5:00

BehemotCat

31-Jan-07 5:00

What is the simpliest way to make a direct system call in managed C# (i.e. equivalent to system() function in C)?

I'm unable to find it on the internet..

Wizard_0131-Jan-07 6:10

Wizard_01

31-Jan-07 6:10

If you'd like to call a function in the external library, you should look at DllImportAttribute and P/Invoke mechanism in .NET.

Wizard_01

BehemotCat31-Jan-07 7:36

BehemotCat

31-Jan-07 7:36

No, I'd like to execute a shell command, for example 'chkdsk' or 'rm' or 'dir' (whatever). In the old ANSI C this was done by calling system(string) function from stdlib. I can't find a corresponding solution in .NET. If I have to, I will use P/Invoke to call system(...), but I don't know what library I have to import either (I don't think it is stdlib.dll..?).

Dan Neely31-Jan-07 8:23

Dan Neely

31-Jan-07 8:23

I believe you want the System.Diagnostics.Process class.

--
Rules of thumb should not be taken for the whole hand.

Luc Pattyn31-Jan-07 8:23

31-Jan-07 8:23

Have a look at the Process class.
For simple commands a simple Process.Start(string) will do.

Smile | :)

Luc Pattyn

User Control and Window form

BehemotCat31-Jan-07 9:30

BehemotCat

31-Jan-07 9:30

Thanks a lot folks!
That was exactly what I was looking for.

biswabhusan31-Jan-07 4:33

biswabhusan

31-Jan-07 4:33

Hi,

I have a user control in a window form. In user control i have a button.
On click over this button i want to change the window form label text.

How i can do it ?

I am new to c#. please help

Re: User Control and Window form

V.31-Jan-07 4:44

31-Jan-07 4:44

delegates and events.
It's too difficult to explain in short text, but you can look up examples on google or MSDN.

V.
I found a living worth working for, but haven't found work worth living for.

Re: User Control and Window form

xstoneheartx31-Jan-07 5:45

xstoneheartx

31-Jan-07 5:45

I think the simplest way is:
1- add a usercontrol to your project
2- add a button, named in Button1 to your usercontrol, set Button1 "Modifiers" property to Public.
3- build your project.
4- after adding your user control, named in UserControl1 to your form, add this lines of code:
-------------------
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
AddHandler UserControl1.Button1.Click, AddressOf Button_Click
End Sub
Private Sub Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
'do your task here
End Sub
-------------------
5- what you wanted is done

Re: User Control and Window form

Luc Pattyn31-Jan-07 8:25