ASP.NET

Response.Redirect behavior

11-Dec-12 12:09

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ASP.NET

Member 468595610-Dec-12 19:59

Member 4685956

10-Dec-12 19:59

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Re: ASP.NET

Richard MacCutchan10-Dec-12 21:32

Richard MacCutchan

10-Dec-12 21:32

Not exactly a difficult one, but Expresso[^] will help you.

One of these days I'm going to think of a really clever signature.

Re: ASP.NET

AmitGajjar11-Dec-12 6:48

AmitGajjar

11-Dec-12 6:48

You need to read two MSDN articles. that will give you idea about how can you create regular expression,

and here it is,

http://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex.aspx[^]
http://msdn.microsoft.com/en-us/library/2k3te2cs%28v=vs.80%29.aspx[^]

Thanks
-Amit Gajjar (MinterProject)

AnalogNerd10-Dec-12 9:11

AnalogNerd

10-Dec-12 9:11

Given the following code in an .ASPX webforms application :

try
{
    // a bunch of code, database stuff, etc.

    Response.Redirect("somePage.aspx");
}
catch (Exception ex)
{
   // Error Logging
}
finally
{
    // object cleanup and disposal
}

I'm wondering if the code in the Finally block (or any code that might be outside of the whole try/catch) would ever be hit.

Doesn't the Response.Redirect() immediately redirect making any code that follows useless? Or do I just not understand how this works?

David Mujica10-Dec-12 10:01

David Mujica

10-Dec-12 10:01

Not trying to be a smart-ass, but why don't you just try it?

Place some dummy code in the finally block and see if it executes. (Use a break-point)

My hunch is that the finally code will execute. Also it may depend on which event the Response-Redirect is placed. (PageLoad, PageInit, ButtonClick, etc)

Post your results, so we all can learn. Java | [Coffee]

AnalogNerd10-Dec-12 10:16

AnalogNerd

10-Dec-12 10:16

I'm beyond mortified that I didn't think of that. Especially since after posting the question I ran the code to check something else, but putting a break point there just never occurred to me. Sigh | :sigh:

Ok, so thanks to David's suggestion I have an answer.

As it is written that code will throw an exception on the Response.Redirect with the following message:

Quote:
{Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack.}

However, it still does the redirect after going through the finally block.

Changing the Response.Redirect to

Response.Redirect("SomePage.aspx", false);

will save it from throwing the exception, but will still run the code in the finally and any code after it and then will do the Redirect.

Live and learn.

modified 11-Dec-12 9:26am.

Shameel10-Dec-12 21:28

Shameel

10-Dec-12 21:28

As you've already figured out, code in the finally block is guaranteed to execute no matter what (unless the runtime host decides otherwise or a system error forcefully terminates the process itself)

AmitGajjar11-Dec-12 6:54

AmitGajjar

11-Dec-12 6:54

Finally block will always execute, no matter if you redirect your page or throwing some exception.

Finally block will not execution on only Some Exceptions[^]

When you pass 2nd optional Boolean parameter, it indicate whether you would like to complete page execution or just want to redirect page and leave current execution.

Thanks
-Amit Gajjar (MinterProject)

ZurdoDev12-Dec-12 4:36

ZurdoDev

12-Dec-12 4:36

You already have your answer but to explain Response.Redirect a little more: It is telling the Response object to redirect the user to the new page. What happens is the client gets that message and then requests somePage.aspx. So, it roundtrips but your C# thread will finish. It's essentially just adding a property to the Response object.

Server.Transfer will still finish your C# thread (finally will still run) but the client will not roundtrip. Execution will stay on the server and go to somePage.aspx and execute it and send the Response object back to the client.

There are only 10 types of people in the world, those who understand binary and those who don't.

ERROR while updating image in database

AnalogNerd12-Dec-12 4:46

AnalogNerd

12-Dec-12 4:46

Very well put. Thanks ryanb31.

Ani199110-Dec-12 6:18

Ani1991

10-Dec-12 6:18

when i m trying to update image in sql database i m getting error as"Cannot bulk load. The file "System.Byte[]" does not exist."
my code is as follows.pls help.
protected void Button1_Click(object sender, EventArgs e)
{
{
if (FileUpload1.HasFile)
{
byte[] productImage = FileUpload1.FileBytes;

string constr = "Server=AOD257; Database=Edusocial;User ID=sa; Password=password";
string query = "UPDATE Profile SET [Pic] = (SELECT Pic.* from Openrowset(Bulk '" + productImage + "', Single_Blob) MyImage) where Id =11651658";

SqlConnection con = new SqlConnection(constr);
SqlCommand com = new SqlCommand(query, con);
com.Parameters.Add("@Pic", SqlDbType.Image).Value = productImage;

con.Open();
int result = com.ExecuteNonQuery();

con.Close();

if (result > 0)
{
Response.Redirect("Default.aspx");
}
}
else
{
lblmessage.Text = "Please Select Image File";
lblmessage.Visible = true;
}
}

}

jkirkerx10-Dec-12 10:37

10-Dec-12 10:37

I can't see how that would work, mixing unicode with bytes to enter into a blob.

"UPDATE Profile SET [Pic] = (SELECT Pic.* from Openrowset(Bulk '" + productImage + "', Single_Blob) MyImage) where Id =11651658";

versus

"UPDATE Profile SET [Pic] = productImage WHERE Id =11651658";

in which the latter is pure bytes from the file upload.

Ani199110-Dec-12 21:15

Ani1991

10-Dec-12 21:15

"UPDATE Profile SET [Pic] = '"+productImage+"' WHERE Id =11651658"

this query is working fine.but then image in image box is broked.its not been displayed.pls help.

Richard Deeming11-Dec-12 0:54

Richard Deeming

11-Dec-12 0:54

You're nearly there:

"UPDATE Profile SET [Pic] = @Pic WHERE Id = 11651658"

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

jkirkerx11-Dec-12 7:26

making a class with streamreader thread safe - perhaps using monitor or a singleton

11-Dec-12 7:26

I don't think you wrap a blob in single quotes, you use it like an integer or number.

The other post is correct, but he forgot to say that you use a parameter to store the data, and use the parameter again in your TSQL.

http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlparameter.aspx[^]

jkirkerx9-Dec-12 11:45

Re: making a class with streamreader thread safe - perhaps using monitor or a singleton

9-Dec-12 11:45

So I separated some write functions, that update a XML file into separate classes, that generate a thread in the background to open, update and write the XML file using streamreader and streamwriter.

So I'm new to threads on vb managed code, and just found that StreamReader is not thread safe. I did some research and one MSDN article says I need to wrap the streamreader in textreader and synchronize.

I did some more research, stumbled across monitor.enter and monitor exit, and the singleton class, so that only 1 instance of the class can run at a time.

So I have a file called "Landing.xml" and I'm interested in only have 1 instance of the class work the file at a time.

Just looking for suggestions, or help with implementing. Will post code is someone asks.

jkirkerx9-Dec-12 16:14