Re: Printing in C#.net - C# Discussion Boards

DataAdapter.Update Method Exception: "Concurrency Voilation: the update command affected 0 records..."

signbit12-Aug-05 1:14

12-Aug-05 1:14

I am using MySqlConnector for .NET (version 1.0.4), I am using the following code for dataAdapter's update command:

this.codeListAdapter = new MySqlDataAdapter(
			"SELECT * FROM CodeList", this.myConnection);
			
MySqlCommand codeListUpdateCmd = new MySqlCommand(
				"UPDATE CodeList SET ProviderID=?ProviderID WHERE DestCode='?DestCode'", myConnection);
codeListUpdateCmd.Parameters.Add("?DestCode", MySqlDbType.VarChar, 10, "DestCode");
codeListUpdateCmd.Parameters.Add("?ProviderID", MySqlDbType.Int16,
				0, "ProviderID");
codeListAdapter.UpdateCommand = codeListUpdateCmd;

codeList = new DataTable("CodeList");
this.codeListAdapter.Fill(codeList);

and then I am using the following code, (after changing some rows of 'codeList' ofcourse):

codeListAdapter.Update(codeList);
codeList.AcceptChanges();

but it throws the Exception mentioned above, what might be the problem?

The structure of the 'CodeList' table is like this:

+-------------+-------------+------+-----+---------+-------+
| Field       | Type        | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+-------+
| DestCode    | varchar(10) |      | PRI |         |       |
| Destination | varchar(50) | YES  |     | NULL    |       |
| ProviderID  | int(11)     |      | MUL | 0       |       |
+-------------+-------------+------+-----+---------+-------+

Thanks in advance...

- A programmer's national anthem; "AAAAAHHHHH!!!!"

How to change the Color of Tittle bar in a Windows Form?

pubududilena12-Aug-05 1:07

pubududilena

12-Aug-05 1:07

hi all,
I need to change the Color of Tittle Bar in a Windows Form..How can I do it?

thanks in advance..

How to Color Tool Bars using C#?

pubududilena12-Aug-05 1:04

pubududilena

12-Aug-05 1:04

hi all,
I need to Color Tool Bar and need to add Blue water mark for buttons when mouse on the Tool Bar Buttons?.
How do I suceed this?.

thanks in advance.

Printing in C#.net

Ming Luo12-Aug-05 1:02

Ming Luo

12-Aug-05 1:02

Hello everybody!
I want to print a document out with A4 paper size programmatically. But I don't know how to define the precise paper size in C#. And also, if I don't use the form's location, how can I locate a particular position of the paper? Could anybody help me with this please!
Thanks in advance

Asura

Re: Printing in C#.net

Guffa12-Aug-05 2:00

Guffa

12-Aug-05 2:00

This is what I gathered from MSDN in a few minutes:

Choose one of the page sizes from PrinterSettings.PaperSizes collection and put it in the PageSettings.PaperSize property.

---
b { font-weight: normal; }

Re: Printing in C#.net

Marshall12-Aug-05 2:06

Marshall

12-Aug-05 2:06

Ming Luo wrote:
I want to print a document out with A4 paper size programmatically.

The prefered method is to allow the user to select the paper size since their needs may change after the application is released. To do this, implement a PageSetupDialog. If A4 is the default paper size for the printer, it will already be set in the dialog. If it is not the default size, I believe you could create a PaperSize object, set it to a PaperKind of A4 in PageSettings before printing (or showing the PageSetupDialog). Check the MSDN documentation on PageSettings[^] and PaperKind Enumeration[^].

To implement PageSetupDialog, you can use this code snip from the MSDN article[^] on PageSetupDialog Class in a print button handler. (Note this code assumes a ListBox named ListBox1 that will display the settings (used to indicate how to get the values after the user clicks OK in the dialog) and a PageSetupDialog named PageSetupDialog1.

        // Initialize the dialog's PrinterSettings property to hold user<br />
        // defined printer settings.<br />
        PageSetupDialog1.PageSettings = <br />
            new System.Drawing.Printing.PageSettings();<br />
<br />
        // Initialize dialog's PrinterSettings property to hold user<br />
        // set printer settings.<br />
        PageSetupDialog1.PrinterSettings = <br />
            new System.Drawing.Printing.PrinterSettings();<br />
<br />
        //Do not show the network in the printer dialog.<br />
        PageSetupDialog1.ShowNetwork = false;<br />
<br />
        //Show the dialog storing the result.<br />
        DialogResult result = PageSetupDialog1.ShowDialog();<br />
<br />
        // If the result is OK, display selected settings in<br />
        // ListBox1. These values can be used when printing the<br />
        // document.<br />
        if ( result == DialogResult.OK)<br />
        {<br />
            object[] results = new object[]{ <br />
                PageSetupDialog1.PageSettings.Margins, <br />
                PageSetupDialog1.PageSettings.PaperSize, <br />
                PageSetupDialog1.PageSettings.Landscape, <br />
                PageSetupDialog1.PrinterSettings.PrinterName, <br />
                PageSetupDialog1.PrinterSettings.PrintRange};<br />
            ListBox1.Items.AddRange(results);<br />
        }

If this doesn't work for you or give you enough clues, post back and let us know.

Marshall

If you continue to do the same things you always did,
don't be surprised if you get the same results you always got.

Re: Printing in C#.net

Ming Luo12-Aug-05 2:20

Ming Luo

12-Aug-05 2:20

Thanks for your code. But I think what I need is to define the paper size programmatically before the page dialog. Because there is a form need to be filled. For example, if give me a check, I need to fill in the address and customer name information in it, so I need to define the precise position of the address row and customer row in the check, then I put the check into the printer, it will print it. Just like the teller does. Actually it's not a check, what I am doing is a invoice which is A4 size. So another problem is that how can I define the location of the field I need to fill in my program??? Any idea please ?

Thanks very much

Asura

Re: Printing in C#.net

Marshall12-Aug-05 2:41

Marshall

12-Aug-05 2:41

Ming Luo wrote:
how can I define the location of the field

There are many options. Try this CP article on DaReport PrintDocument[^] to see one approach at positioning objects (including text) on a printed document such as a check. It is not the most straight-forward approach but it is clever and extensible.

Marshall

If you continue to do the same things you always did,
don't be surprised if you get the same results you always got.

Re: Printing in C#.net

| Muhammad Waqas Butt |14-Aug-05 2:41

| Muhammad Waqas Butt |

14-Aug-05 2:41

Check Out This Code:
PageSetupDialog psd= new PageSetupDialog();
psd.PageSettings.PaperSize = psd.PrinterSettings.PaperSizes[ 4 ]; // 4 denotes the paper index you pass different index and check the Paper size. On my printer paper sizes A4 exits on 4 index.

Try this then tell me.

Muhammad Waqas Butt
waqasb4all@yahoo.com: Cool | :cool:

Muhamad Waqas Butt
waqasb4all@yahoo.com

Which child has been brought to front?

bouli12-Aug-05 0:31

bouli

12-Aug-05 0:31

Hello gurus,

I'd like to know how to detect which child has been activated in an MDI?

The MdiChildActivate does not show me which child window has been activated, or maybe there is a cast to do somewhere in the code handler...

Best regards.

Fred.

There is no spoon.

Re: Which child has been brought to front?

mav.northwind12-Aug-05 0:52

mav.northwind

12-Aug-05 0:52

Although I must admit that I didn't work with MDI much, I'd expect the sender parameter to be the MdiChild that's being activated.

Did you check this?

Regards,
mav

Re: Which child has been brought to front?

bouli12-Aug-05 0:54

bouli

12-Aug-05 0:54

you're right, I'm not familiar with MDIs...
I mainly do dialogs :P

Thanks Smile | :)

fred.

There is no spoon.

try catch and return value

Os Sutrisno12-Aug-05 0:00

Os Sutrisno

12-Aug-05 0:00

I'm writing a function as below:

public string returnString()
{
try
{
//open connections
return var1;
}
catch (Exception ex)
{
//write to trace
}
finally
{
//close connections
}
}

I'm getting an error that says the function will not return a value in some execution.

Where should I return the value? After finally?

Dead | X|

Re: try catch and return value

Colin Angus Mackay12-Aug-05 0:19

Colin Angus Mackay

12-Aug-05 0:19

If your try fails, it will jump to the catch block. There is no return statement in the catch block therefore, once the error is handled it does not know what to return out of the method.

You either need an additional return in the catch block or you need to return something after the finally block.

My: Blog | Photos
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Re: try catch and return value

Os Sutrisno12-Aug-05 0:34

Os Sutrisno

12-Aug-05 0:34

For example, if I am retrieving data from a DB and returning the dataset. An exception occurs and no data is retrieved.

In this case, should I still return the dataset in the catch block\after finally?

My initial thought was that I wouldn't return anything if an exception occurs. Frown | :(

Re: try catch and return value

Colin Angus Mackay12-Aug-05 0:38

Colin Angus Mackay

12-Aug-05 0:38

You must return something as your method signature tells the caller that you will. If the thing fails and you have nothing then return null;

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Re: try catch and return value

Os Sutrisno12-Aug-05 0:40

Os Sutrisno

12-Aug-05 0:40

I see!

Thanks very much Colin!

Regards,
Os

Row colors in DataGrids?

kbalias11-Aug-05 23:56

kbalias

11-Aug-05 23:56

Hi
Can the backcolor of a specific row in datagrid be set. I want to compare the values in an arraylist against the values in the datagrid and if a match is found I want to change the backcolor of that row so that the user can easily see the matches.

On that point can the backcolor of all the rows in the datagrid be reset to White in one property or do I need to loop through the datagrid and set each row's backcolor to White.

Thanks

Kobus

Re: Row colors in DataGrids?

Alomgir Miah12-Aug-05 6:16

Alomgir Miah

12-Aug-05 6:16

public class DataGridColoredTextBoxColumn : DataGridTextBoxColumn

{

protected override void Paint(System.Drawing.Graphics g,

System.Drawing.Rectangle bounds, System.Windows.Forms.CurrencyManager

source, int rowNum, System.Drawing.Brush backBrush, System.Drawing.Brush

foreBrush, bool alignToRight)

{

// the idea is to conditionally set the foreBrush and/or backbrush

// depending upon some crireria on the cell value

// Here, we color anything that begins with a letter higher than 'F'

try{

object o = this.GetColumnValueAtRow(source, rowNum);

if( o!= null)

{

char c = ((string)o)[0];

if( c > 'F')

{

// could be as simple as

// backBrush = new SolidBrush(Color.Pink);

// or something fancier...

backBrush = new LinearGradientBrush(bounds,

Color.FromArgb(255, 200, 200),

Color.FromArgb(128, 20, 20),

LinearGradientMode.BackwardDiagonal);

foreBrush = new SolidBrush(Color.White);

}

}

}

catch(Exception ex){ /* empty catch */ }

finally{

// make sure the base class gets called to do the drawing with

// the possibly changed brushes

base.Paint(g, bounds, source, rowNum, backBrush, foreBrush, alignToRight);

}

}

}

Live Life King Size
Alomgir Miah

Image Capture

Member 217284911-Aug-05 23:26

Member 2172849

11-Aug-05 23:26

Hello every body
i need ur help.
plz any body sendme the code in c# tha connect the webcam and then extract frames and save it into my local drive,
i realy thankful to that person.
waiting
best regards
abdullah

abd

Re: Image Capture

Kimocat12-Aug-05 13:35

Kimocat

12-Aug-05 13:35

search for webcam in the search bar of cp & u,ll find many things Smile | :)

The C Lover ..

Resizing Gif-images that is transparent

thomasa11-Aug-05 22:21

thomasa

11-Aug-05 22:21

How can I find out witch color in a Gif image that is transparent?

I'm creating small icons of images in an ASP page, and I'm writing the images to the output stream.

First I'm resizing the image, witch data I get from a memory stream (this data is an transparent image, and in this code example I use PNG to try to get transparency):

<br />
public Bitmap _bitmap = null;<br />
private void getGraphicsFromImageNotStretched(MemoryStream ms, int hight, int width)<br />
{ <br />
Image image = Image.FromStream(ms, true); <br />
<br />
double orgHight = (double)image.Height;<br />
double orgWidth = (double)image.Width;<br />
if((orgHight * hight) > (orgWidth * width))<br />
{<br />
double ratio = (orgWidth * width) / (orgHight * hight);<br />
_bitmap = new Bitmap(image, (int)((double)width * ratio), hight);<br />
_bitmap.Palette = image.Palette; <br />
_bitmap.MakeTransparent();<br />
}<br />
else<br />
{<br />
double ratio = (orgHight * hight) / (orgWidth * width);<br />
_bitmap = new Bitmap(image, width, (int)((double)hight * ratio));<br />
_bitmap.Palette = image.Palette;<br />
_bitmap.MakeTransparent();<br />
} <br />
<br />
image.Dispose(); <br />
}<br />

Then I write the data to the output stream:

<br />
public static byte[] GenerateImageBytes(Bitmap theBitmap)<br />
{<br />
byte[] bytes = null; <br />
<br />
// save the image to the output stream<br />
System.IO.MemoryStream ms = new System.IO.MemoryStream();<br />
theBitmap.Save(ms, ImageFormat.Png);<br />
bytes = ms.ToArray();<br />
ms.Close(); <br />
<br />
return bytes;<br />
}<br />

This result in an image that is not treansparent Frown | :(

If anyone has a code-snip or an example to get this working, I'll be happy as a dove.

Thanks
Thomas

question on using ref keyword

ppp00111-Aug-05 22:13

ppp001

11-Aug-05 22:13

Hi all,

I have tested using ref in passing reference to method,
e.g.

Car car1 = new Car();
Change(ref car);
...

void Change(ref Car car)
{
car.id = 1;
//car = null;
//car = new Car();
}

it seem that by passing car by ref can null the reference of the car,
or change the reference of the car, it can do more that just
by Change(Car car) (i.e. without the ref keyword.
Then why we not always add ref keywords to the method, so
more capabilities are achieved ? What are the disadvantages
of using ref ??

Thanks

Re: question on using ref keyword

levgiang11-Aug-05 22:34

levgiang

11-Aug-05 22:34

The disadvantages of ref keyword is it can change the reference of car.There is a situation we don't want change the reference of car,so we don't need use the ref keyword.

When you want pass type value parameters and want change the variable pass to method ,you use the ref keyword.and if you dont't want change the variables pass to method,you shoudn't use the ref keyword.

le van giang

Re: question on using ref keyword

ppp00112-Aug-05 0:21

ppp001

12-Aug-05 0:21

Thanks

But it seems there are no harm to change the reference by ref.
And this add more functionality by using ref (except we cant
pass property and not initialized object reference to it ).
So, in what other situation that it is harmful to use ref ?

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