Re: Painting Reversible Rectangle - C# Discussion Boards

13-Aug-07 7:03

I am using GDI methods (ROP/XOR methods) to draw a reversible rectangle on FORM_A. When I display another form FORM_B (Dialog) on top of FORM_A and close it (FORM_B), part for of the reversible rectangle (where FORM_B was displayed) is erased. I tried calling FORM_Update and FORM_Paint events from FORM_Activated event. It worked in single form application but not in MDI application. Any suggestions are appreciated.

Cheers,
Prasad

Christian Graus13-Aug-07 8:19

Christian Graus

13-Aug-07 8:19

Wow - you're still going with this ? You need to invalidate the form that is being obscured, if it's not working in an MDI app, then you're invalidating the wrong thing. Having said that, showing and hiding a form, should fire the paint event on it's own. You do NOT call the paint event, you call Invalidate() to force it to fire.

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 )

T.D.Prasad13-Aug-07 8:37

13-Aug-07 8:37

Thanks for your answer. Still it is not working. If I use Invalidate() method it is completely erasing the rubberband rectangle.

I do not think that is the answer (may be I am wrong)

Regards,
Prasad

Luc Pattyn13-Aug-07 8:51

13-Aug-07 8:51

There are two rules to get it right:
- do all painting inside a Paint handler (and nowhere else);
- call Invalidate() if you have changed the parameters of the paintable objects.

If it does not behave, it's because you did not obey the above rules.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

this weeks tips:
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T.D.Prasad13-Aug-07 9:02

13-Aug-07 9:02

Thanks for the reply. I cannot handle all the painting inside paint event handler, because reversible rectangles must be drawn inside mouse eventhandlers.

I am attaching all the code (although it is long), please let me know what modifications I have to make.

<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.AutoValidate = System.Windows.Forms.AutoValidate.EnablePreventFocusChange;<br />
            this.ClientSize = new System.Drawing.Size(401, 282);<br />
            this.Controls.Add(this.button1);<br />
            this.DoubleBuffered = true;<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 />
                using (Graphics g = Graphics.FromHwnd(this.Handle))<br />
                {<br />
                    if (mouseMoving)<br />
                        RubberRectangle(g, XDown, YDown, oldX, oldY);<br />
                    RubberRectangle(g, XDown, YDown, e.X, e.Y);<br />
                    mouseMoving = true;<br />
                    oldX = e.X;<br />
                    oldY = e.Y;<br />
                }<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(Graphics g, int X1, int Y1, int X2, int Y2 )<br />
		{			<br />
			RubberbandRectangle rect = 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 />
<br />
            using (Graphics g = Graphics.FromHwnd(this.Handle))<br />
            {<br />
                g.Clear(this.BackColor);<br />
                if (haveRect)<br />
                {                    <br />
                    RubberRectangle(g, XDown, YDown, oldX, oldY);<br />
                }<br />
            }<br />
		}<br />
<br />
        private void button1_Click(object sender, EventArgs e)<br />
        {<br />
            MessageBox.Show("err yty");<br />
            this.Invalidate();<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 />

Luc Pattyn13-Aug-07 9:14

13-Aug-07 9:14

Hi,

what is it that would make it impossible to do all painting in a Paint handler ?

you can have one Rectangle (say rubberRect) and one boolean class member
(say showRubberRect), have your mouse handlers modify those variables AND call
Invalidate(), and have your Paint handler paint the rubber band (if showRubberRect
is true). That would be a clean approach that follows both rules; and it would work.

About fancy XOR drawing: if you manage to do it in a mouse handler, you could
do it also in a Paint handler.

For the kind of things you want to achieve, it may be wise to set up a
double-buffering scheme.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Christian Graus13-Aug-07 8:55

Christian Graus

13-Aug-07 8:55

T.D.Prasad wrote:
If I use Invalidate() method it is completely erasing the rubberband rectangle.

I thought you posted code yesterday where you drew your rubberband in your paint event. I recall telling you that you needed to, then changing my answer when I saw that you were.

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 )

T.D.Prasad13-Aug-07 9:12

Re: Highlight Value on Tab

13-Aug-07 9:12

In the code that I have attached to my previous message I used Invalidate method inside button click event hadler(after messagebox.show statement). If I remove this statement partial rectangle is visible. if I keep it thewhole rectangle is erased after I close the MessageBox.

When I minimise and then maximise, then also rectangle is erased. I am not able to find a solution to this problem and breaking my head since yesterday. Any help to overcome this problem willbe highly appreciated.

Regards,
Prasad

Highlight Value on Tab

Joemama6113-Aug-07 5:03

Joemama61

13-Aug-07 5:03

I'm trying to have the value in a numeric up down highlight when selected by tab (for faster modification of the value). Currently it inserts at the beginning of the value. Anyone know if this is possible?

Luc Pattyn13-Aug-07 5:38

Re: Highlight Value on Tab

13-Aug-07 5:38

Hi, add an Enter handler with this content:
numericUpDown1.Select(0, numericUpDown1.Value.ToString().Length);

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Joemama6113-Aug-07 10:39

Joemama61

13-Aug-07 10:39

Is there anyway to do this without referencing all of the numeric up downs, i have about 7 on one form and would like some way (without doing everyone individually) to do this. Thanks for your help!

Re: Highlight Value on Tab

Luc Pattyn13-Aug-07 10:52

13-Aug-07 10:52

Hi,

yes, for all events, if you add a handler programmatically
say with someEvent+=new EventHandler(myHandler);
you can specify the same handler over and over.

if you add a handler through Visual Designer, you can also choose the handler's
name.

And if that handler then needs to differentiate based on the specific control,
it should investigate its first argument ("object sender").

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

SQL connection timeout

Demian Panello13-Aug-07 4:43

Demian Panello

13-Aug-07 4:43

Hi.

I'm writing an application that it connect to a SQL Server 2000 database. For testing I have 2 PC running Windows XP and in one of them I'm running SQL Server 2000.
When I run the application in the same PC where SQL is running the application works fine, but trying to connect from another PC it throws an exception connecting to the database. This is what I have:

My connection string:

string source = "Server = DEC-DEMIAN; Database = Security; User ID = Terminal2;" +<br />
                  "Password = 123; Trusted_Connection = False;";

Trying to connect from another PC it fails, thowing: "...SQLException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding".

I can't figure out what I missed to configure in SQL Server to be able to get remote connections. I have checked Server Properties -> Connections in SQL and it's ok.

Any help will be apreciatte.

Thankx

Demian.

"I have always wished that my computer would be as easy to use as my
telephone. My wish has come true. I no longer know how to use my telephone."
-Bjarne Stroustrup, computer science professor, designer of C++
programming language (1950- )

Justin Perez13-Aug-07 4:48

13-Aug-07 4:48

On the server, have you enabled named pipes? I have had that same problem before, and It was because I didn't enable named pipes.

I get all the news I need from the weather report - Paul Simon (from "The Only Living Boy in New York")

Demian Panello13-Aug-07 5:03

Demian Panello

13-Aug-07 5:03

I don't know.

Where should I find the "named pipes"??.

Justin Perez13-Aug-07 5:12

13-Aug-07 5:12

I don't quite remember, Google it.

I get all the news I need from the weather report - Paul Simon (from "The Only Living Boy in New York")

How to dump more than one row from table into the array !!!! please Help

satsumatable13-Aug-07 6:35

satsumatable

13-Aug-07 6:35

These specify the time, in seconds, to wait for the server to respond before generating an error. The default value is 15 (seconds).

"Connect Timeout=10;"
-or-
"Connection Timeout=10;"

ANKUR2213-Aug-07 4:41

ANKUR22

13-Aug-07 4:41

hello ,
my self ankur , i am very new to .net (C#)
I had made an function in vb .net but same logic is not workin in C#
please help.
I had Written an Following Code .
try
{
da = new SqlDataAdapter(Cmd);
dt = new DataTable();
da.Fill(dt);
int i=0,j=0,p=0,k=0,m=0;
string[] arr = new string[((dt.Columns.Count) * 3)];
if (dt.Rows.Count <= 0) return arr;
for (j = 0; j <= dt.Rows.Count - 1; j++)
{
if ((j == 0))
{
for (i = 0; i <= dt.Columns.Count - 1; i++)
{
arr[i] =dt.Rows[0].ItemArray[i].ToString();
//(dt.Rows[0].Item(i));
p = i;
}
}
if ((j == 1))
{
k = p + 1;
//For k = i To dt.Columns.Count - 1
for (i = 0; i <= dt.Columns.Count - 1; i++)
{

arr[k] =dt.Rows[1].ItemArray[i].ToString();
k = k + 1;
}
}
if ((j == 2))
{
m = k;
//For k = i To dt.Columns.Count - 1
for (i = 0; i <= dt.Columns.Count - 1; i++)
{

arr[m] =dt.Rows[2].ItemArray[i].ToString();
m = m + 1;
}
//Next
}

}

Re: How to dump more than one row from table into the array !!!! please Help

Justin Perez13-Aug-07 5:17

Re: How to dump more than one row from table into the array !!!! please Help

13-Aug-07 5:17

What do you mean by "not working?"

I get all the news I need from the weather report - Paul Simon (from "The Only Living Boy in New York")

bit_cmdr13-Aug-07 6:50

bit_cmdr

13-Aug-07 6:50

I'm not really sure exactly what you're trying to accomplish here, but I think this code below might suit you better:

<br />
string[] arr = new string[dt.Rows.Count * dt.Columns.Count];<br />
int i = 0;<br />
int j = 0;<br />
foreach (DataRow dr in dt.Rows)<br />
{<br />
    j = 0;<br />
    foreach (DataColumn dc in dt.Columns)<br />
    {<br />
        arr[i] = dr.ItemArray[j].ToString();<br />
        j++;<br />
        i++;<br />
    }<br />
}<br />

The results of this would be an array structured as:
[0] = row1 col1
[1] = row1 col2
[2] = row1 col3
[3] = row2 col1
...

Hope that helps, if it doesn't be a little more clear on what you're trying to accomplish and maybe we can come up with something better.

- Arcond

Days of the week

kibromg13-Aug-07 4:25

kibromg

13-Aug-07 4:25

Hi all,
Is there any function that allows me to get an out put of Monday from a Datetime datataype?

For instance Day(2007/08/13) will return 13.
But i want to get Monday.

How do i get that?

Thanks for your time.

Re: Days of the week

Justin Perez13-Aug-07 4:32