Re: how to set digits precision of a float - C# Discussion Boards

Mike Hankey26-Mar-07 16:55

26-Mar-07 16:55

Its a matter of scope

If you have the following;

static int resulta = 0;
public static void MethodOne()
{
result a;
}
public static void MethodTwo()
{
result b;
result a; //Is legal

}

then result a can be referenced in MethodTwo

but if you have

public static void MethodOne()
{
int result a;
}
public static void MethodTwo()
{
result b;
result a; //Is not valid because it is not in scope
}

Hope this helps and that I understood you correctly

Mike

Everybody gotta be somebody

.Two methods one output

JMOdom26-Mar-07 14:57

JMOdom

26-Mar-07 14:57

[No Message]

Re: .Two methods one output

Christian Graus26-Mar-07 15:05

Christian Graus

26-Mar-07 15:05

You want to try again ?

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

how to set digits precision of a float

uowzd0126-Mar-07 14:45

uowzd01

26-Mar-07 14:45

Morning! I am calculating a percentage and the float value is, say 12.34567, I know float has 7 digits precision, is there any easy way to set the precision to 4 or 2 digits after .? So that I have 12.3 or 12.34, Thanks a lot.

Re: how to set digits precision of a float

Christian Graus26-Mar-07 14:46

Christian Graus

26-Mar-07 14:46

for rendering, you can use string.format("0.###"), with a # for each level of precision. You can't change what a float can store, however.

Re: how to set digits precision of a float

uowzd0126-Mar-07 15:23

uowzd01

26-Mar-07 15:23

Thank you very much for your quck help, you gave me a thought of doing it in a different way, the actual code is String.format({0:#.##}, float).

Re: how to set digits precision of a float

Christian Graus26-Mar-07 15:39

Christian Graus

26-Mar-07 15:39

Yes, that also works.

Re: how to set digits precision of a float

Saeed Jafarian7-Aug-11 12:32

Saeed Jafarian

7-Aug-11 12:32

hi i have a code like this:

float f = d / (c * b * a) / 1000000;
string.Format("{0 Blush | :O

.00}",f);
txtdansite1.Text = f.ToString();

it still does not work and it has the float`s default precision.
help me please

Re: how to set digits precision of a float

Bala subramanyam M26-Mar-07 18:19

Bala subramanyam M

26-Mar-07 18:19

Console.WriteLine("{0:N2}",value);

(M.BALA SUBRAMANYAM)

Re: how to set digits precision of a float

Saeed Jafarian12-Aug-11 13:57

Saeed Jafarian

12-Aug-11 13:57

in win application we don`t use console and this syntax does not help,for example:
textbox1.text=string.format("{0:n2}", variable);

and the textbox1 shows: 0.00

Re: how to set digits precision of a float

Sujith C Jose27-Mar-07 0:55

Sujith C Jose

27-Mar-07 0:55

Or simply use

Math.Round(floatvalue,2);

Sujith

Re: how to set digits precision of a float

Saeed Jafarian12-Aug-11 14:02

Saeed Jafarian

12-Aug-11 14:02

float f=2.37037E-08
Math.Round(f, 2);
textbox1.Text = f.ToString();

still the same problem and the textbox shows 2.37037E-08
Frown | :(

how to copy folder in csharp ?

hdv21226-Mar-07 12:51

hdv212

26-Mar-07 12:51

hi how to copy folders ??

Re: how to copy folder in csharp ?

Christian Graus26-Mar-07 13:04

Christian Graus

26-Mar-07 13:04

I'm not sure if there's a Directory.Copy, I don't think so. I suspect you need to create the folder and copy the files recursively.

Re: how to copy folder in csharp ?

Balaji Prabu AL27-Mar-07 1:14

Balaji Prabu AL

27-Mar-07 1:14

Hi,

There is no direct methods available to Copy a folder as such in C#. You have to itrate the entire source folder and then you have to copy individual File.

Thanks
Balaji

How to call the paint event handler

laura131626-Mar-07 11:07

laura1316

26-Mar-07 11:07

Hi All,

I am tring to call a paint event with a timer so that the points change depending on the location. I am going to have a for loop that incrementally changes the X location. So I am not sure quite how to do this. This is my paint code:

<br />
private void PictureBox1_Paint(object sender, PaintEventArgs e)<br />
        {<br />
            Filtered_Tilt f = new Filtered_Tilt();<br />
            Graphics g = e.Graphics;<br />
            Size ballsize = new Size(30, 30);<br />
            Rectangle r = new Rectangle(f.front, ballsize);<br />
            Pen p = new Pen(Color.Blue, 4);<br />
            front.X = f.x;<br />
            front.Y = f.y;<br />
            g.DrawEllipse(p, r);<br />
        }<br />

I have a timer function that updates the X I then need to call the paint event to refresh the ellipse on the form. How do I do this? x is a global int variable. front is a global point.
***** GLobal Variable*****
public int x, y;
public Point front;

<br />
private void timer1_Tick(object sender, EventArgs e)<br />
        {<br />
            for (int i = 0; i < pictureBox1.Width; i++)<br />
            {<br />
                x = i;<br />
            }<br />
            // How to call the paint event handler to pass it the new x value?<br />
            <br />
        }<br />

Thanks,
Laura

Re: How to call the paint event handler

Christian Graus26-Mar-07 11:31

Christian Graus

26-Mar-07 11:31

You can never call the Paint event directly. Instead, you force it by doing this:

Invalidate();

Re: How to call the paint event handler

Ravi Bhavnani26-Mar-07 11:43

Ravi Bhavnani

26-Mar-07 11:43

As CG has pointed out, you call Invalidate() to invalidate the window, which will cause the OS to eventually call your paint handler. In addition, you can call Update() to force the OS to paint your window immediately.

/ravi

This is your brain on Celcius
Home | Music | Articles | Freeware | Trips
ravib(at)ravib(dot)com

Re: How to call the paint event handler

laura131626-Mar-07 11:49

laura1316

26-Mar-07 11:49

Thanks so much that worked! Big Grin | :-D

How do I get a pointer to a C# function?

MattPlusJC26-Mar-07 10:11

MattPlusJC

26-Mar-07 10:11

I need to use a Win32 (unmanaged) function, and need to a way to get a pointer to a CSharp function. Is this possible in CSharp?

Re: How do I get a pointer to a C# function?

Christian Graus26-Mar-07 10:21

Christian Graus

26-Mar-07 10:21

Yes, I'm not sure of the mechanics right now, but I know it can be done.

You could look into the Canon SDK wrapper I have here as an article ( I didn't write that bit ). Or you could check www.pinvoke.net to see how it's done via an API that does it.

Here is an article

Ennis Ray Lynch, Jr.26-Mar-07 10:45

Ennis Ray Lynch, Jr.

26-Mar-07 10:45

Not from CP but will bring you in the right direction

http://www.informit.com/guides/content.asp?g=dotnet&seqNum=473&rl=1

File Not Found

Re: How do I get a pointer to a C# function?

MattPlusJC26-Mar-07 12:46

MattPlusJC

26-Mar-07 12:46

Alright thanks guys! I'll check this info out ASAP.

Re: How do I get a pointer to a C# function?

Luc Pattyn27-Mar-07 13:42

Luc Pattyn

27-Mar-07 13:42

Yes, it's called a delegate.
Example:

/// <summary>
/// delegate used for EnumWindows() callback function
/// </summary>
public delegate bool LP_EnumWindowsProc(IntPtr hWnd, int lParam);

/// <summary>
/// Enumerate all windows, calling a delegate for each of them.
/// </summary>
/// <param name="ewp"></param>
/// <param name="lParam"></param>
/// <returns></returns>
[DllImport("user32.dll", CallingConvention=CallingConvention.StdCall)]
public static extern int EnumWindows(LP_EnumWindowsProc ewp, object lParam);

private static bool CollectVisibleWindows(IntPtr hWnd, int lParam) {
IntPtr ptr=(IntPtr)hWnd;
if (LP_User32.IsWindowVisible(ptr)) list.Add(ptr);
}

EnumChildWindows(ptr, new LP_EnumWindowsProc(CollectVisibleChildWindows), 0);

Hope this helps.

Luc Pattyn

[My Articles]

C# and convenient string parsing for '\r\n'

LCI26-Mar-07 8:25

LCI

26-Mar-07 8:25

I have a string of text similiar to below. I am new to c# and was wondering of there is any built in functionality that allows string parsing in c# to figure out new lines based on the carriage return line feed in a string of teext such as below. Or is it just like usual, where you must search for the '\r\n'?

EE.DDDDDDDD
14:00 03/13/2007 00176
14:00 03/13/2007 00311 AAAAAAA
* DDDDDDDD
TXT
LIC:DLLLLL 041 TAB:51100D6 EXPIRE: 05/15/2006
VIN:1D7HA00000000 VYR:2003 VMA:DODG VMO:SQ1 VST:12PU
NAM:DAN,DEXTER,DDASS CUST#:D02620977
ADR:16102 PRINCE LN
CTY:HEY ST:TT ZIP:85889 GVW:000000

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