Create textbox using array & insert the text box values into sqlserver database using c# - C# Discussion Boards

Re: How to read a value in a memory address using c#!

Daniel Grunwald22-Jan-09 20:50

22-Jan-09 20:50

Do you have any references for that?

In my understanding, "int* IncrementPointer(int *p) { return p++; }" is a simple increment of the pointer, no runtime checks. It doesn't matter whether p points to unmanaged memory or a pinned object on the GC heap.
.NET doesn't even try to remember the 'valid range' - it's just a simple pointer!

Looking for 'unchecked' in the C# specification, it only talks about integer overflows. No mention of pointers there.

However, when you dereference an invalid pointer, you might get a nice managed exception. But that's just because .NET converts Win32 access violations to exceptions (to NullReferenceException if the pointer was near null, AccessViolationException otherweise). It is still possible to read invalid data/crash the process/whatever - they're unsafe pointers!

Re: How to read a value in a memory address using c#!

Jon Rista23-Jan-09 4:38

Jon Rista

23-Jan-09 4:38

I ran into the problem a while back on a project that was using pointers to manipulate a Bitmap object. I had a bug in my math tha was causing me to read past the end of the bitmap, and I was getting an AccessViolationException. I'll see if I can dig the code up. Interestingly enough, I just tried to proove the theory by writing a simple loop that passed over an array with a pointer, and when reading past the end, I recieved neither a NullReferenceException nor an AccessViolationException. Given that, perhapse the exception was something specific to the Bitmap class in .NET...

Re: How to read a value in a memory address using c#!

Ennis Ray Lynch, Jr.22-Jan-09 10:36

Ennis Ray Lynch, Jr.

22-Jan-09 10:36

To use pointers in C# you must use unsafe code either through the compiler option /unsafe or through an unsafe block. After that the code is the same in C++ and C#. My article on Grayscale conversion uses pointers.

http://www.codeproject.com/KB/graphics/quickgrayscale.aspx[^]

Need software developed? Offering C# development all over the United States, ERL GLOBAL, Inc is the only call you will have to make.

If you don't ask questions the answers won't stand in your way.

Most of this sig is for Google, not ego.

Re: How to read a value in a memory address using c#!

PIEBALDconsult22-Jan-09 18:55

PIEBALDconsult

22-Jan-09 18:55

Ennis Ray Lynch, Jr. wrote:
either through the compiler option /unsafe or through an unsafe block

Don't you need both? Confused | :confused:

Re: How to read a value in a memory address using c#!

Guffa22-Jan-09 20:07

Guffa

22-Jan-09 20:07

Yes.

Despite everything, the person most likely to be fooling you next is yourself.

dynamic drag and drop window component

anishkannan22-Jan-09 6:56

anishkannan

22-Jan-09 6:56

Anybody help me

i am new c# developing. i want dynamic drag window component for example the label or button will move after execute the project .

And one more thing on that time want call back method, if the label drag on the another label of same form

Thankyou

Re: dynamic drag and drop window component

Rutvik Dave22-Jan-09 8:19

Rutvik Dave

22-Jan-09 8:19

Replace Panel with Label1 in the following code.

private bool _mouseDown; 
private Point _mousePos; 

private void panel1_MouseDown(object sender, MouseEventArgs e) 
{ 
if (e.Button == MouseButtons.Left) 
{ 
_mouseDown = true; 
_mousePos = new Point(e.X, e.Y); 
} 

} 

private void panel1_MouseMove(object sender, MouseEventArgs e) 
{ 
if (_mouseDown) 
{ 
panel1.Location = PointToClient(this._panel1.PointToScreen(new Point(e.X - _mousePos.X, e.Y - _mousePos.Y))); 
} 

private void panel1_MouseUp(object sender, MouseEventArgs e) 
{ 

if (_mouseDown) 
{ 
_mouseDown = false; 
} 
}

Create textbox using array & insert the text box values into sqlserver database using c#

ramya_jkumar22-Jan-09 6:53

ramya_jkumar

22-Jan-09 6:53

Hi i have created dynamically 2 text boxes in a row using a loop based on the user selection from dropdownlist box .i.e if user selects 2 in dropdownlistbox then there will be 2 rows of that text boxes will be generated dynamically...

My problem is i want to read the 2 text box values in a row and insert the values in to the database (sqlserver 2005) table,in the same way for all the geneated rows ??? can some body help me in solving my problem..

i dont knw how to read the values and inset into the table..pls pls some body give some idea or steps to follow...waiting for the answer eagerly.. i'm attaching the code fro reference:

protected void Page_Load(object sender, EventArgs e)
{
int i=0;
if (!Page.IsPostBack)
for (i = 0; i < 1000; i++)
{
DropDownList1.Items.Add(i.ToString());
}

if (Page.IsPostBack)
{
this.Rows = DropDownList1.SelectedIndex;
}

CreateDynamicTable();
}
protected int Rows
{
get
{
return ViewState["Rows"] != null ? (int)ViewState["Rows"] : 0;
}
set
{
ViewState["Rows"] = value;
}
}
protected int Columns
{
get
{
return ViewState["Columns"] != null ? (int)ViewState["Columns"] : 0;
}
set
{
ViewState["Columns"] = value;
}
}

private void CreateDynamicTable()
{
PlaceHolder1.Controls.Clear();

int tblRows = Rows;
int tblCols = Columns;
Table tbl = new Table();
PlaceHolder1.Controls.Add(tbl);
for (int i = 0; i < tblRows; i++)
{
TableRow tr = new TableRow();
for (int j = 0; j < 4; j++)
{
if (j % 2 == 0)
{
TableCell tc = new TableCell();
Label label1 = new Label();
label1.Text = "RowNo:" + i + " " + "ColumnNo:" + " " + j;
tc.Controls.Add(label1);
tr.Cells.Add(tc);

}
else
{
TableCell tc = new TableCell();
TextBox txtBox = new TextBox();
tc.Controls.Add(txtBox);
tr.Cells.Add(tc);
}

}
tbl.Rows.Add(tr);
}

ViewState["dynamictable"] = true;
}

protected override void LoadViewState(object earlierState)
{
base.LoadViewState(earlierState);
if (ViewState["dynamictable"] == null)
CreateDynamicTable();
}

Ramya

Re: Create textbox using array & insert the text box values into sqlserver database using c#

Wendelius22-Jan-09 8:08

Wendelius

22-Jan-09 8:08

To store the values to the database you would for example:
- create a SqlConnection[^]
- create a SqlCommand[^] and set INSERT INTO... statement to it
- add SqlParameters[^] to the SqlCommand.Parameters collection for your values
- open the connection
- create a loop where you set the parameter values and then execute the command
- close the connection

The need to optimize rises from a bad design.My articles[^]

calculating slope of a line

steini144122-Jan-09 6:29

steini1441

22-Jan-09 6:29

Hello
I need some help writing a couple of classes in C#.
One of them should encapsulate a point in a grid and the other one has a method to get 2 points with different X values and calculate the slope.
I'm quite lost since I haven't done any programming for over 2 years and my apologies if this doesn't make any sense.

here's what I got so far with the first class, it looks sketchy to me.

class Pointless
    {
        private int X, Y;

        public Pointless(int nullx, int nully)
        {
            X = nullx;
            Y = nully;
            
        }

        public void setX(int i)
        {
            i = 2;
            X = i;
        }
        public void setY(int b)
        {
            b = -4;
            Y = b;
            
        }

        public int getX()
        {
            return X;
            
        }

        public int getY()
        {
            return Y;
        }
        
        
    }