i have problem with GetResponse Method

[minofino]

Hello,

I am Beginner in VB.NET
So tell me why I cannot make more than 2 Requests in VB.NET
In the Same Time.

for Example : If you have a Form with one Button, Study this code in
Button Click Event.

'====================================================
        Dim Url(2) As String
        Url(0) = "................"          ' First Url Put Any Url Instead points
        Url(1) = "................"          ' Second Url Put Any Url Instead points
        Url(2) = "................"          ' Third Url Put Any Url Instead points
 
        Dim Wq(2) As HttpWebRequest
        Dim Wp(2) As HttpWebResponse
 
        For I As Byte = 0 To 2
          Wq(I) = WebRequest.Create(Url(I))
          Wq(I).Timeout = 10000
          Try
              Wp(I) = Wq(I).GetResponse
              Text = "Url " + Cstr(I) + " is OK"
          Catch exp As WebException
              Text = "Url " + Cstr(I) + " is " + exp.Status.ToString
          End Try
        Next I
'====================================================
 

Why the Third Url cannot Response and throw Exception "TimeOut" ?
Please Help me... THANKS.

[vanc]

Hello,

I am Beginner in VB.NET
So tell me why I cannot make more than 2 Requests in VB.NET
In the Same Time.

for Example : If you have a Form with one Button, Study this code in
Button Click Event.

'====================================================
        Dim Url(2) As String
        Url(0) = "................"          ' First Url Put Any Url Instead points
        Url(1) = "................"          ' Second Url Put Any Url Instead points
        Url(2) = "................"          ' Third Url Put Any Url Instead points
 
        Dim Wq(2) As HttpWebRequest
        Dim Wp(2) As HttpWebResponse
 
        For I As Byte = 0 To 2
          Wq(I) = WebRequest.Create(Url(I))
          Wq(I).Timeout = 10000
          Try
              Wp(I) = Wq(I).GetResponse
              Text = "Url " + Cstr(I) + " is OK"
          Catch exp As WebException
              Text = "Url " + Cstr(I) + " is " + exp.Status.ToString
          End Try
        Next I
'====================================================
 

Why the Third Url cannot Response and throw Exception "TimeOut" ?
Please Help me... THANKS.

Because the Third Url does not exist. You declared only 2 url variables and call the third url?!!!
Dim url(2) As String --> url(0) and url(1)
Cheers.

[minofino]

Hello Dear thanks for replying

But there is not a problem with Url array because index start with zero value
So i declared string array contains 3 urls from 0 to 2.
Replace Dim Url(2) .. with Dim Url(3) for example not diffrent and the
Problem still presents.

I searched the Net and found some problems like mine and the this problem happen :

beacauses the programmer can Declare one instance for httpwebrequest class and reuses it many times.

OR Declare the instance(means Variable) in Custom Class which Programmer
Create it and Declare many instance of that Custom Class.

But I cannot understand these 2 solution , Please help me.

[vanc]

I don't see any problem when you fixed the upper bound of URL array. I don't do VB.NET so I converted your code into C# and changed a bit to make it run. Here is the code

string[] Url = new string[3];
        Url[0] = "http://www.google.com";        
        Url[1] = "http://www.yahoo.com";        
        Url[2] = "http://www.bytes.com";       
 
        WebRequest[] Wq = new WebRequest[3];
        WebResponse[] Wp = new WebResponse[3];
 
        for (byte i = 0; i<= 2; i++)
        {
            Wq[i] = WebRequest.Create(Url[i]);
            Wq[i].Timeout = 10000;
 
            try
            {
                Wp[i] = Wq[i].GetResponse();
                Response.Write("Url " + i.ToString() + " is OK");
            }
            catch (WebException exp)
            {
                Response.Write("Url " + i.ToString() + " is " + exp.Status.ToString());
            }
        }
 

Be noticed that I used the WebResponse and WebRequest classes, not HttpWebResponse and Request. Those three Urls all response correctly. Check your code again and give me some feedbacks. Cheers.

[Curtis Rutland]

I copied your code exactly, except for declaring Text as a string. I used these three urls:
http://www.google.com
http://www.engadget.com
http://bytes.com
And everything worked fine. The problem could be specifically with your third url. Make sure that you have access to the url from the server, and make sure that the user profile that the server uses can be authenticated on the site that the third url points to. If the site requires authentication, the user that ASP.NET uses may not have access.

Try your own code with these other urls and see what happens.

[minofino]

Hello, thanks again for replying
You are right threre is a problem with the Urls which i use to test my code
So i wrote These Urls to Study them :

Url(0) = "http://get.games.yahoo.com/dnld_handler;_ylt=
Ao9no6nbCm_kT9D_UzF1fHd0v8sh?gamekey=doggiedash"

Url(1) = "http://get.games.yahoo.com/dnld_handler?gamekey=
bigcityadventuresydney"

Url(2) = "http://get.games.yahoo.com/dnld_handler?gamekey=supple"

When I Changed the Order of Urls By Changing index of Array Items it gives
me the same result.

Infact, the Result "Ok" or "TimeOut" is happening in random way.
The error "TimeOut" most happen in Urls point to big files or slowly Urls.

When I made Array of 20 light Urls which point to very small files or html files
Like your Example "yahoo", "google" and "bytes" sites the urls must be "OK"

Please Study my Urls and Test Others Urls point to big files or slowly Urls.

At Last, I need to solve that problem very much beacuse I am devolping :
A Download Manager Program.

I am waiting for your help Thanks.