C# Discussion Boards - CodeProject

Luc Pattyn26-May-09 6:44

26-May-09 6:44

Hi,

if you want to catch *all* Exception types and threat them identically, then no there is no use in having separate catch blocks.

BTW: logging is fine, not dealing with the Exception probably is a poor choice, since (unless you rethrow the Exception) the caller will be unaware something went wrong.

Smile | :)

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Re: C# multiple catch blocks

proganon26-May-09 7:24

proganon

26-May-09 7:24

Thanks Luc. I am planning on doing something with the exception besides swallowing it...Probably rethrow, I just haven't decided yet.

Re: C# multiple catch blocks

Vikram A Punathambekar26-May-09 7:53

Vikram A Punathambekar

26-May-09 7:53

proganon wrote:
Is there any purpose for using multiple (specific) catch blocks if all exceptions will be handled the same way?

A resounding No.

The only place where this would be valid is if you wanted to catch and handle CustomException1 and CustomException2 in the same way and leave the rest for calling code to handle, where said Exception types are unrelated to each other.

Cheers,
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Re: C# multiple catch blocks

Pete O'Hanlon26-May-09 11:34

Pete O'Hanlon

26-May-09 11:34

proganon wrote:
Is there any purpose for using multiple (specific) catch blocks if all exceptions will be handled the same way?

Yes. This provides the ability to handle specific exceptions in a sensible fashion - for instance, you might have a bit of code that updates a database, and the SQL Connection terminates unexpectedly during the operation - you might want to attempt the update again (having reopened the connection). If you get a different type of exception, you probably wouldn't want to attempt the update again.

There's just one example of doing this.

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My Project gives an error out of VS... How can I debug?

SimpleData26-May-09 6:08

SimpleData

26-May-09 6:08

Hi My C# project throws a System.NullException outside VS so I can't find where the problem is. How can I debug while my application runs outside VS?

Thanks in advance.

Re: My Project gives an error out of VS... How can I debug?

OriginalGriff26-May-09 6:15

OriginalGriff

26-May-09 6:15

Two obvious possibilities:
1) run it inside VS and see where the error is.
2) put in a try - catch block and print out the exception content.

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Re: My Project gives an error out of VS... How can I debug?

SimpleData26-May-09 6:16

SimpleData

26-May-09 6:16

The weird thing is that it doesn't give an error while working inside VS.

I will try try-catch block with printing out exception content.

Re: My Project gives an error out of VS... How can I debug?

SimpleData26-May-09 6:36

SimpleData

26-May-09 6:36

Thanks to your help I found where the error is. But I can't understand why it throws an error.

Here is the code:

string gorev = null;
string pcadi = "*****";

WebClient wc = null;
Stream s = null;
StreamReader sr = null;

try
{
    wc = new WebClient();
    s = wc.OpenRead(main + get + "?updatecheck=" + pcadi);
    sr = new StreamReader(s);

    gorev = sr.ReadLine();

}
catch { gorev = null; }
finally { sr.Close(); sr.Dispose(); s.Close(); s.Dispose(); wc.Dispose(); }

Re: My Project gives an error out of VS... How can I debug?

Luc Pattyn26-May-09 6:50

Luc Pattyn

26-May-09 6:50

When you use catch(Exception exc) { Console.WriteLine(exc.ToString());} or something similar you will get all available details about the exception often including the line number. And it is wise to tell Visual Studio (or any other IDE) to always display line numbers in editor windows, so now you know exactly which line goes wrong.

BTW: The fact that a program sometimes works just fine does *not* prove it is correct.

Smile | :)

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Re: My Project gives an error out of VS... How can I debug?

0x3c026-May-09 6:34

0x3c0

26-May-09 6:34

I think that some versions of VS allow you to attach the debugger to a managed application. Not sure how you would go about this though - I use the Express edition

how to display default image in datagridview in c#.net 3.5 Win Forms?

Narendra Reddy Vajrala26-May-09 5:43

Narendra Reddy Vajrala

26-May-09 5:43

Hi Experts,
am working with c#.net 3.5, Windows Application
How can i add a default image to every row of my datagridview?
please help me out.

Thanks In Advance.
Blush | :O

Re: how to display default image in datagridview in c#.net 3.5 Win Forms?

Henry Minute26-May-09 12:52

Henry Minute

26-May-09 12:52

The easiest way to do this is to use an unbound DataGridViewImageColumn.

Something like this:

// Create the image column.
DataGridViewImageColumn imageCol = new DataGridViewImageColumn();
imageCol.DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;
imageCol.ImageLayout = DataGridViewImageCellLayout.Normal;
imageCol.Frozen = true;
imageCol.Name = "Image";
imageCol.HeaderText = "";

// Move the column to the left
// column out of the way.
imageCol.DisplayIndex = 0;

// By default, show the generic image.
imageCol.Image = genericImage; // <==================== put your image here

// Add the image column to the grid.
dataGridView1.Columns.Add(imageCol);

Henry Minute

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an array question [modified]

bluetx26-May-09 5:05

bluetx

26-May-09 5:05

Hi Guys

i have an array below

string stringArray = new strinArray[12];

stringArray[0] = "0,1";
stringArray[1] = "1,3";
stringArray[2] = "1,4";
stringArray[3] = "2,1";
stringArray[4] = "2,4";
stringArray[5] = "3,7";
stringArray[6] = "4,3";
stringArray[7] = "4,2";
stringArray[8] = "4,8";
stringArray[9] = "5,5";
stringArray[10] = "5,6";
stringArray[11] = "6,2";

i need to transform like below

List<List<string>> listStringArray = new List<List<string>>();

listStringArray[["1","3","4"],["1","4"],["7"],["3","2","8"],["5","6"],["2"]];

how is that possible?

modified on Tuesday, May 26, 2009 11:27 AM

Re: an array question

Ennis Ray Lynch, Jr.26-May-09 5:12

Ennis Ray Lynch, Jr.

26-May-09 5:12

"someString".Split and logic.

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Re: an array question

bluetx26-May-09 5:14

bluetx

26-May-09 5:14

i know to split man.i actually need to logic Big Grin | :-D

Re: an array question

harold aptroot26-May-09 5:16

harold aptroot

26-May-09 5:16

The logic isn't the hard part here.. actually there is no hard part at all.

Re: an array question

Ennis Ray Lynch, Jr.26-May-09 5:22

Ennis Ray Lynch, Jr.

26-May-09 5:22

Try looking at the documentation for the generic list constructor. If you can't figure it out from there you may have a PEBKAC error.

Re: an array question

OriginalGriff26-May-09 6:14

OriginalGriff

26-May-09 6:14

Ennis Ray Lynch, Jr. wrote:
you may have a PEBKAC error

Not heard that one before - thank you (and google for the explanation)! Laugh | :laugh:

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Re: an array question

tom57200726-May-09 5:15

tom572007

26-May-09 5:15