C# Discussion Boards - CodeProject

George_George12-Aug-07 22:36

12-Aug-07 22:36

Hello everyone,

I am wondering if I am using TCPClient class in C#, how to setup timeout value? Timeout I mean, when connects to server for the 1st time, and during <timeout> interval, if no server response is received, the GetStream method will return will return other than wait forever.

thanks in advance,
George

Connection to SQL !

mrkeivan12-Aug-07 21:59

mrkeivan

12-Aug-07 21:59

Hey Guys, whats going on ? I want to check the the way I connect to sql and see if there's a more professional way, so please bare me !!! thanx

First I declare my SqlConnection, SqlDataAdapter and DataSet

SqlConnection InstConn = new SqlConnection();<br />
      SqlDataAdapter InstDA = new SqlDataAdapter();<br />
      DataSet DS = new DataSet();

then i create my Command text (Select, delete or update)
SqlCommand ChkCmd = new SqlCommand();

for selection then I fill my data set
InstDA .Fill(DS , "Table Name");

and if its Insert Delete or edit I use
ChkCmd .ExecuteNonQuery();

Not to mention that for edit I use SqlParameter.

so what do you think ? Is there a better way for doing this ?
and I also have another question, how can I prevent users from manipulating my database by entering some SQL command in a text box ! I know in ASP.net It authomatically prevent this, is this the same in C# Win or we have to manually do the same thing ?

Thanx
Mr.K

Re: Connection to SQL !

Giorgi Dalakishvili12-Aug-07 22:09

Giorgi Dalakishvili

12-Aug-07 22:09

Have a look at this: http://www.codeproject.com/cs/database/SqlInjectionAttacks.asp[^]

#region signature
my articles
#endregion

vertical align in richtextbox

Cuciu12-Aug-07 21:38

Cuciu

12-Aug-07 21:38

Does anyone know how i can vertical align the lines in a richtesxtbox? pls help Smile | :)

c# - Painting problem

T.D.Prasad12-Aug-07 21:27

T.D.Prasad

12-Aug-07 21:27

I am trying to draw a rubberband rectangle using one of the methods suggested in this forum. My problem is: after drawing the rectangle, if I move another window (for example a messagebox) over the rectangle (ruberband rectangle drawn earlier) part of this rectangle is not getting pained properly. Any help is highly appreciated.

The code that I am using is given below.

<br />
//<br />
// MainForm.cs - Demo shell application for the RubberbandRectangle class.<br />
// project created on 9/4/2003 at 11:43 PM by cthomas<br />
//<br />
<br />
using System;<br />
using System.Windows.Forms;<br />
using System.Drawing;<br />
<br />
namespace RubberbandShape<br />
{<br />
	class MainForm : System.Windows.Forms.Form<br />
	{<br />
		public MainForm()<br />
		{<br />
			InitializeComponent();<br />
        }<br />
	<br />
		// THIS METHOD IS MAINTAINED BY THE FORM DESIGNER<br />
		// DO NOT EDIT IT MANUALLY! YOUR CHANGES ARE LIKELY TO BE LOST<br />
		void InitializeComponent() {<br />
            this.button1 = new System.Windows.Forms.Button();<br />
            this.SuspendLayout();<br />
            // <br />
            // button1<br />
            // <br />
            this.button1.Location = new System.Drawing.Point(323, 256);<br />
            this.button1.Name = "button1";<br />
            this.button1.Size = new System.Drawing.Size(75, 23);<br />
            this.button1.TabIndex = 0;<br />
            this.button1.Text = "button1";<br />
            this.button1.UseVisualStyleBackColor = true;<br />
            this.button1.Click += new System.EventHandler(this.button1_Click);<br />
            // <br />
            // MainForm<br />
            // <br />
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);<br />
            this.ClientSize = new System.Drawing.Size(401, 282);<br />
            this.Controls.Add(this.button1);<br />
            this.Name = "MainForm";<br />
            this.Text = "Rubber Band Shape Drawing";<br />
            this.Paint += new System.Windows.Forms.PaintEventHandler(this.MainForm_Paint);<br />
            this.MouseUp += new System.Windows.Forms.MouseEventHandler(this.MainForm_MouseUp);<br />
            this.MouseMove += new System.Windows.Forms.MouseEventHandler(this.MainForm_MouseMove);<br />
            this.MouseDown += new System.Windows.Forms.MouseEventHandler(this.MainForm_MouseDown);<br />
            this.ResumeLayout(false);<br />
<br />
		}<br />
			<br />
		[STAThread]<br />
		public static void Main(string[] args)<br />
		{<br />
			Application.Run(new MainForm());<br />
		}<br />
<br />
		private bool mouseDown = false;<br />
		private bool mouseMoving = false;<br />
		private bool haveRect = false;<br />
		private int XDown;<br />
		private int YDown;<br />
        private int oldX;<br />
        private Button button1;<br />
		private int oldY;<br />
<br />
		// The MouseDown event will be used to initialize the one corner<br />
		// of the RubberRectangle when the Left mouse button is down.<br />
		// If the Right mouse button is pressed and there is a<br />
		// RubberRectangle on the screen, it is erased.<br />
		void MainForm_MouseDown(object sender,<br />
		                       System.Windows.Forms.MouseEventArgs e)<br />
		{<br />
			if( e.Button == MouseButtons.Left )<br />
			{<br />
				mouseDown = true;<br />
				XDown = e.X;<br />
				YDown = e.Y;<br />
				mouseMoving = false;<br />
			}<br />
			else if( e.Button == MouseButtons.Right )<br />
			{<br />
				if( haveRect )<br />
				{<br />
					haveRect = false;	// Clear the flag<br />
					Invalidate();		// Clear out the rectangle.<br />
				}<br />
			}<br />
		}<br />
		<br />
		// The MouseMove event is used top acutally draw the rectangle<br />
		// after erasing to previously draw one if the mouse has moved since.<br />
		void MainForm_MouseMove(object sender,<br />
		                       System.Windows.Forms.MouseEventArgs e)<br />
		{<br />
			if( mouseDown )<br />
			{<br />
				if( mouseMoving )<br />
					RubberRectangle( XDown, YDown, oldX, oldY );<br />
				RubberRectangle( XDown, YDown, e.X, e.Y );<br />
				mouseMoving = true;<br />
				oldX = e.X;<br />
				oldY = e.Y;<br />
			}<br />
		}<br />
		<br />
		// Clears that flags that were used during drawing and sets a flag<br />
		//that indicates the presence of the rectangle.<br />
		void MainForm_MouseUp(object sender,<br />
		                     System.Windows.Forms.MouseEventArgs e)<br />
		{<br />
			mouseDown = false;<br />
			mouseMoving = false;<br />
			haveRect = true;<br />
		}<br />
		<br />
		// Draws the RubberRectangle onto the client area using the<br />
		// RubberbandRectangle class.<br />
		private void RubberRectangle( int X1, int Y1, int X2, int Y2 )<br />
		{<br />
			System.Drawing.Graphics g = Graphics.FromHwnd( this.Handle );<br />
			<br />
			RubberbandRectangle rect<br />
			= new RubberbandRectangle();<br />
			rect.DrawXORRectangle( g, X1, Y1, X2, Y2 );<br />
		}<br />
		<br />
		// Paints the test objects onto the client area.  If a RubberRectangle<br />
		// was there also, repaints that, too.<br />
		void MainForm_Paint(object sender,<br />
		                   System.Windows.Forms.PaintEventArgs e)<br />
		{            <br />
			Graphics g = Graphics.FromHwnd( this.Handle );<br />
/*<br />
			g.FillRectangle( Brushes.Black, 0, 0, 150, 150 );<br />
			g.FillRectangle( Brushes.Wheat, 150, 0, 150, 150 );<br />
			g.FillRectangle( Brushes.Red, 0, 150, 100, 100 );<br />
			g.FillRectangle( Brushes.Green, 100, 150, 100, 100 );<br />
			g.FillRectangle( Brushes.Blue, 200, 150, 100, 100 );<br />
 */<br />
			if( haveRect )<br />
				RubberRectangle( XDown, YDown, oldX, oldY );<br />
		}<br />
<br />
        private void button1_Click(object sender, EventArgs e)<br />
        {<br />
            MessageBox.Show("err yty");<br />
        }<br />
		<br />
	}	<br />
	<br />
	//*******************************************************<br />
    public enum PenStyles<br />
    {<br />
        PS_SOLID = 0,<br />
        PS_DASH = 1,<br />
        PS_DOT = 2,<br />
        PS_DASHDOT = 3,<br />
        PS_DASHDOTDOT = 4<br />
    }<br />
    public class RubberbandRectangle<br />
    {<br />
        // These values come from the larger set of defines in WinGDI.h,<br />
        // but are all that are needed for this application.  If this class<br />
        // is expanded for more generic rectangle drawing, they should be<br />
        // replaced by enums from those sets of defones.<br />
        private int NULL_BRUSH = 5;<br />
        private int R2_XORPEN = 7;<br />
        private PenStyles penStyle;<br />
        private int BLACK_PEN = 0;<br />
<br />
        // Default contructor - sets member fields<br />
        public RubberbandRectangle()<br />
        {<br />
            penStyle = PenStyles.PS_DOT;<br />
        }<br />
<br />
        // penStyles property get/set.<br />
        public PenStyles PenStyle<br />
        {<br />
            get { return penStyle; }<br />
            set { penStyle = value; }<br />
        }<br />
<br />
        public void DrawXORRectangle(Graphics grp,<br />
                                      int X1, int Y1, int X2, int Y2)<br />
        {<br />
            // Extract the Win32 HDC from the Graphics object supplied.<br />
            IntPtr hdc = grp.GetHdc();<br />
<br />
            // Create a pen with a dotted style to draw the border of the<br />
            // rectangle.<br />
            IntPtr gdiPen = CreatePen(penStyle,<br />
                          1, BLACK_PEN);<br />
<br />
            // Set the ROP cdrawint mode to XOR.<br />
            SetROP2(hdc, R2_XORPEN);<br />
<br />
            // Select the pen into the device context.<br />
            IntPtr oldPen = SelectObject(hdc, gdiPen);<br />
<br />
            // Create a stock NULL_BRUSH brush and select it into the device<br />
            // context so that the rectangle isn't filled.<br />
            IntPtr oldBrush = SelectObject(hdc,<br />
                                 GetStockObject(NULL_BRUSH));<br />
<br />
            // Now XOR the hollow rectangle on the Graphics object with<br />
            // a dotted outline.<br />
            Rectangle(hdc, X1, Y1, X2, Y2);<br />
<br />
            // Put the old stuff back where it was.<br />
            SelectObject(hdc, oldBrush); // no need to delete a stock object<br />
            SelectObject(hdc, oldPen);<br />
            DeleteObject(gdiPen);		// but we do need to delete the pen<br />
<br />
            // Return the device context to Windows.<br />
            grp.ReleaseHdc(hdc);<br />
        }<br />
<br />
        // Use Interop to call the corresponding Win32 GDI functions<br />
        [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]<br />
        private static extern int SetROP2(<br />
                IntPtr hdc,		// Handle to a Win32 device context<br />
                int enDrawMode	// Drawing mode<br />
                );<br />
        [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]<br />
        private static extern IntPtr CreatePen(<br />
                PenStyles enPenStyle,	// Pen style from enum PenStyles<br />
                int nWidth,				// Width of pen<br />
                int crColor				// Color of pen<br />
                );<br />
        [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]<br />
        private static extern bool DeleteObject(<br />
                IntPtr hObject	// Win32 GDI handle to object to delete<br />
                );<br />
        [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]<br />
        private static extern IntPtr SelectObject(<br />
                IntPtr hdc,		// Win32 GDI device context<br />
                IntPtr hObject	// Win32 GDI handle to object to select<br />
                );<br />
        [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]<br />
        private static extern void Rectangle(<br />
                IntPtr hdc,			// Handle to a Win32 device context<br />
                int X1,				// x-coordinate of top left corner<br />
                int Y1,				// y-cordinate of top left corner<br />
                int X2,				// x-coordinate of bottom right corner<br />
                int Y2				// y-coordinate of bottm right corner<br />
                );<br />
        [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]<br />
        private static extern IntPtr GetStockObject(<br />
                int brStyle	// Selected from the WinGDI.h BrushStyles enum<br />
                );<br />
<br />
        // C# version of Win32 RGB macro<br />
        private static int RGB(int R, int G, int B)<br />
        {<br />
            return (R | (G << 8) | (B << 16));<br />
        }<br />
    }<br />
}<br />
<br />

Cheers,
Prasad

Re: c# - Painting problem

Albu Marius12-Aug-07 22:31

Albu Marius

12-Aug-07 22:31

Don't paste your whole code. I don't think it will be read. Try to find out which part of it generates that problem and then Smile | :)

ask for help in regards with that specific problem giving as an example your code fragment.

I am fighting against the Universe...
Reference-Rick Cook

Re: c# - Painting problem

Cuciu12-Aug-07 22:42

Cuciu

12-Aug-07 22:42

u must clear de background in the graphic object

// Paints the test objects onto the client area. If a RubberRectangle<br />
// was there also, repaints that, too.<br />
void MainForm_Paint(object sender,<br />
System.Windows.Forms.PaintEventArgs e)<br />
{<br />
	Graphics g = Graphics.FromHwnd(this.Handle);<br />
/*<br />
	g.FillRectangle( Brushes.Black, 0, 0, 150, 150 );<br />
	g.FillRectangle( Brushes.Wheat, 150, 0, 150, 150 );<br />
	g.FillRectangle( Brushes.Red, 0, 150, 100, 100 );<br />
	g.FillRectangle( Brushes.Green, 100, 150, 100, 100 );<br />
	g.FillRectangle( Brushes.Blue, 200, 150, 100, 100 );<br />
*/<br />
	if (haveRect)<br />
	{<br />
		g.Clear(BackColor);<br />
		RubberRectangle(XDown, YDown, oldX, oldY);<br />
	}<br />
}

Re: c# - Painting problem

T.D.Prasad12-Aug-07 23:51

T.D.Prasad

12-Aug-07 23:51

Cuciu,

Thanks for the suggestion. My problem is partially solved. Still the following problem persists. If I colse the messagebox, while it is on the rubber recatngle, that part is not redrawn.

Further, the suggested method doesn't work if I use "e.Graphics.Clear(BackColor)".

Could you please explain why?

My main problem is the Following:

<br />
        private void FormMap_Paint(object Sender, PaintEventArgs e)<br />
        //----------------------------------------------------<br />
        // OnPaint event handler. Copies bitmap image of Map<br />
        // object to form's canvas when form needs repainting.<br />
        //----------------------------------------------------<br />
        {<br />
            e.Graphics.Clear(this.BackColor);<br />
            e.Graphics.DrawImage(Map.BMP, 0, 0);<br />
            DrawFenceline();<br />
            HiliteOn();<br />
        }<br />

my Map object is stored on a bitmap. In form paint event I am drawing bitmap on to form. Then a fenceline is drawn (a region of rubberband lines) which is used to select a group of objects.

However, when I display a message box (or other form) on this form I am having problems with rubberband lines as explained earlier.

Any help to overcome this problem?

Regards,
Prasad

Re: c# - Painting problem

Christian Graus13-Aug-07 0:31

Christian Graus

13-Aug-07 0:31

When you show your messagebox, call Invalidate() afterwards to force a paint event, which will draw your image again

Christian Graus - Microsoft MVP - C++

"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 )

Re: c# - Painting problem

Christian Graus12-Aug-07 23:52

Christian Graus

12-Aug-07 23:52

I know that GDI+ doesn't offer XOR drawing, but this still looks far too messy to me. What's wrong with just drawing a black ( or white, or whatever ), box in your paint event ?

Christian Graus - Microsoft MVP - C++

"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 )

Reading Numeric and AlphaNumeric Values from Excel

meeram39512-Aug-07 20:10

meeram395

12-Aug-07 20:10

Hi

I have an Excel sheet, has 4 columns. In the first column there is an industry code, which contains both numeric and alphanumeric chararcters. I'm not able to read the values to the dataset if the value is alphabets. For eg. if the value is 1,2,3,4 etc.. it will read. But if the value is 1a, 2b, 3e, 4d etc. then it will read as null. Anybody has any solution for these? Any help would be great. I'll post my code below:

OleDbCommand MyCommand;
OleDbConnection MyConnection;

MyConnection = new OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0;data source=C:\\Projects\\LiquidCreditChains\\CreditCurveMapping.xls;Extended Properties=Excel 8.0;");

if (MyConnection.State != ConnectionState.Closed)
MyConnection.Close();
else
MyConnection.Open();

DataTable dtSector = new DataTable("SectorChains");
objds.Tables.Add(dtSector);

DataColumn dc1 = new DataColumn("Indust_Code");
dc1.DataType = System.Type.GetType("System.String");
dtSector.Columns.Add(dc1);
DataColumn dc2 = new DataColumn("Indust_Number");
dc2.DataType = System.Type.GetType("System.Int64");
dtSector.Columns.Add(dc2);
DataColumn dc3 = new DataColumn("MappingDescription");
dc3.DataType = System.Type.GetType("System.String");
dtSector.Columns.Add(dc3);
DataColumn dc4 = new DataColumn("SubDescription");
dc4.DataType = System.Type.GetType("System.String");
dtSector.Columns.Add(dc4);
DataColumn dc5 = new DataColumn("Mapping_Curve");
dc5.DataType = System.Type.GetType("System.String");
dtSector.Columns.Add(dc5);

MyCommand = new OleDbCommand("select * from [Sheet1$]", MyConnection);
OleDbDataReader dr1 = MyCommand.ExecuteReader();

while (dr1.Read())
{

DataRow newChainRow = objds.Tables[0].NewRow();

newChainRow["Indust_Code"] = dr1[0].ToString();
newChainRow["Indust_Number"]=dr1[1].ToString();
newChainRow["MappingDescription"] = dr1[2].ToString();
newChainRow["SubDescription"]= dr1[3].ToString();
newChainRow["Mapping_Curve"] = dr1[4].ToString();
objds.Tables[0].Rows.Add(newChainRow);
}

Any help in this regard would be great!!

Thanks

Meeram395

Re: Reading Numeric and AlphaNumeric Values from Excel

travlos718-Mar-09 6:14

travlos7

18-Mar-09 6:14

you can find the answer in the following link.... i hope that it helps
http://www.pcreview.co.uk/forums/thread-1240790.php[^]

Re: Reading Numeric and AlphaNumeric Values from Excel

InfoBridgeSolutions17-Aug-10 19:30

InfoBridgeSolutions

17-Aug-10 19:30

Please check the code at http://chetanwarade.wordpress.com/2010/08/18/read-excel-with-ado-net/[^]

Datagrid paging-c# windows application

hemchandars12-Aug-07 20:06

hemchandars

12-Aug-07 20:06

Hi to everybody

I have DB as dat file.I've paging concept works fine.Problem is when i delete or edit or add records, it is showing the first page on data grid( if i have 50 records-per page 20).I need if the record no 45 is updated OR deleted it has to show the current page i.e., 3rd page.I have not used connection string.Plz help me thanks in advance. Smile | :)

Re: Datagrid paging-c# windows application

Jax_qqq12-Aug-07 21:41

Jax_qqq

12-Aug-07 21:41

Hi,

As per my understanding after every edit or add you must be binding your grid somewhere and i think you are not setting its current page index...

Hope it will work...

Thanks

~Anuj~

Re: Datagrid paging-c# windows application

hemchandars13-Aug-07 1:03

hemchandars

13-Aug-07 1:03

i have not used connection string.I've used .dat file as DB, READING AND WRITING DATAS IN TMP TABLE.If anyone has code sample it will be more helpful.Thanks in advance.

how to Read folder contents [modified]

salmonraju12-Aug-07 20:05

salmonraju

12-Aug-07 20:05

Hi,

I am creating a windows application,that contains a folder,with 5 files. how to programaticlly get the names of all the files in that folder(getting names of all the contents of that folder)

Say folder name is "MyXMLFolder" .It contains elemnts as
-Customer.xml
-Employee.Xml
-Bank.xml

I want c# coding to get all the names of the files in "MyXMLFolder" folder

-- modified at 2:13 Monday 13th August, 2007

Re: how to Read folder contents

Michael Sync12-Aug-07 20:18

Michael Sync

12-Aug-07 20:18

DirectoryInfo dir = new DirectoryInfo(@"F:\MyFolder");<br />
FileInfo[] files = dir.GetFiles("*.*");<br />
<br />
Foreach(FileInfo f in files )<br />
{<br />
  Console.WriteLine("Name is : {0}", f.Name);<br />
  Console.WriteLine("Length of the file is : {0}", f.Length);<br />
  Console.WriteLine("Creation time is : {0}", f.CreationTime);<br />
  Console.WriteLine("Attributes of the file are : {0}",<br />
                     f.Attributes.ToString());<br />
}

Ref:

Working with Files in C#[^]

File Information using C#[^]

Hope it helps.

Thanks and Regards,
Michael Sync ( Blog: http://michaelsync.net)

If you want to thank me for my help, please vote my message by clicking one of numbers beside "Rate this message". Why vote? Plz Read it here. Thank you.

Re: how to Read folder contents

salmonraju12-Aug-07 21:02

salmonraju

12-Aug-07 21:02

Thank you, for detailed description,
working

Re: how to Read folder contents

tker12-Aug-07 20:29

tker

12-Aug-07 20:29

Hi,

You need to use the System.IO namespace. The following code will get you all files in a folder as strings in a string array, including the folder path:

string[] files = Directory.GetFiles(@"c:\MyXMLFolder");

Everything you will need to work with files can be found in System.IO.

Regards,

Toby

Re: how to Read folder contents

salmonraju12-Aug-07 21:01

salmonraju

12-Aug-07 21:01

Thank you ,It is working

crystal reports

monuSaini12-Aug-07 19:58

monuSaini

12-Aug-07 19:58

Hello Friends,

I had generated the crystal report.I want to change the connection string but I am unable to do so . Actually their are two database one is testing database and other is live database. So I need to change the connection string.

But I am unable to do so.

Regards,

rahul saini

Re: crystal reports

Imranlogi12-Aug-07 20:33

Imranlogi

12-Aug-07 20:33

Open your crystal report and on the left hand side you will find Field Explorer, under that you will find Database Fields, right click on that and click on Database Expert and the Database Expert Dialog box will open from there choose Project Data or Create New Connection, according to your need.
Thanks

Imran

Re: crystal reports

monuSaini12-Aug-07 20:49

monuSaini

12-Aug-07 20:49

Hello Imran,

If I choose new connection then all the feilds that i had drag from the previous table will delete.

Regards,

rahul saini

Re: crystal reports

Imranlogi12-Aug-07 21:18

Imranlogi

12-Aug-07 21:18

Ya the feilds will get deleted, do one thing what ever feilds you have dragged earlier, select all the feilds and copy it and when u create new report just paste all the feilds as it is, hope this may help.
Thanks

Imran

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