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There are various types of Errors it can be explained as follows. If
we catch errors with coding can make the programmers' and the users' life
a little easier and a lot less graying hair. If you are from a VB6 background;
well throw out the ideas of using On Error Goto or Resume Next-those things
DO NOT EXIST in C#-land. So lets get to the areas of catching errors with
ASP.net and C#.
The Objectives of the Errors :-
Responding to Clients and Errors in ASP.NET
- Select the steps to enable a control to post back data to the
server.
- Use the request and response objects to intercept communication
between a client and the server.
- Enable an ASP.NET page to handle client actions.
- Configure an ASP.NET application to catch exceptions and errors.
- Handle errors that occur in a web application.
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There are following Types of Errors :-
- Logical :- It could be a math error (i.e. division by
zero); mismatches (i.e. adding a string to a number); bad data
output (i.e. allowing invalid time/date on the output) and there
are others as well.
- System :- These can be ASP.net or CLR parser error based
on the something that it doesn't like about the code it is trying
to process. But it could be a memory low on the server or the
server got unplugged.
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The following is the Syntax of the Errors :-
| This is a basic typos
or the improper closing of tags. |
Example#1 :-
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<html>
<head>
<title>Error 1</title>
</head>
<body>
<center>ErrorsRUs</center>
<asp:lbel id="Error" runat="server" text="Ooops…"
/>
</body>
</html>
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The above stated are some common and silly error; we are typing quickly
or forget to close attributes or add spaces to them.
Example#2 :-
<script language="c#"
runat="Server">
void WholePositveNumber(object sender, EventArgs e)
{
if (txtNumber.Text != "")
{
if (!(Char.IsNumber(txtNumber.Text, 0)))
{
if (txtNumber.Text.Substring(0,1) != "-")
{
lblEntered.Text = "Please enter only positive numbers.";
}
else
{
lblEntered.Text = "Please enter number of the positive nature.";
}
}
else if (Convert.ToInt32(txtNumber.Text) == 0)
{
lblEntered.Text = "Please enter a number greater then 0.";
}
else if (Convert.ToInt32(txtNumber.Text) > 0)
{
lblEntered.Text = "Thank you for entering a positive real number.";
}
}
else
{
lblEntered.Text = "Please provide a number.";
}
}
</script>
<html>
<head>
<title> Trapping error a la Manual Style</style>
</head>
<body>
<form method="post" action="PostiveNumbers.aspx"
runat="server" ID="Form1">
<asp:Label text="Enter:" runat="server" />
<asp:Textbox id="txtNumber" runat="server"
/>
<hr />
<asp:Button id="btnEntered" Text="Enter"
onclick="PositiveNumber" runat="server" />
<br />
<asp:Label id="lblEntered" runat="server" />
</form>
</body>
</html> |
The above stated errors are the programmers errors which proggrammers
faced.
The Errors can further be classified as :-
- Active Server Pages error 'ASP 0126' :-You will get Active
Server Pages error ´ASP 0126´ if you try to include
a file that does not exist. This is a straightforward error -
that file is not on your server!
- Active Server Pages error 'ASP 0131' :-Active Server
Pages error ´ASP 0131´ means your server doesn´t
support reference to upper folder.
- ActiveX component can't create object: 'CDONTS.NewMail' :-
Sending mail in ASP is one of the most basic tasks to accomplish.
What happens when you get the error ActiveX component can´t
create object: ´CDONTS.NewMail´?
- Array Subscript Overflow Error :- If you´re
using arrays, it´s very likely at one point or another that
you´ll hit a subscript overflow error.
- ASP Error - Overflow: 'cInt' :- A common error in ASP
is the Overflow: ´cInt´ error. What does it mean when
you overflow a cInt value? How do you fix this?
- ASP Error - The HTTP Headers are already written :- A
very common error in the world of ASP is: The HTTP headers are
already written to the client browser. Any HTTP header modifications
must be made before writing page content.
- ASP Error The requested resource is in use :- The following
error - The requested resource is in use - is caused in ASP by
the ISAPI caching setting in IIS.
- Server Too Busy - Error 500-13 :- If your website keeps
growing and growing, eventually you will hit the error 500-13,
that your server is too busy to handle the requests. What do you
do?
- The requested resource is in use :- The error
"The requested resource is in use" is fairly common
in Windows. If you´re getting this with ASP calls, it usually
means something is not up to date.
- Type Mismatch Error :- Type mismatch is a general error
that happens when you try to stuff one type of value into a variable
of another type.
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