Error handling
If the page is wrong, there is no handling of the error, then the page will display an error that the user may not understand.
Can be used in the ASP script
ON Error ResMe next
......
IF Err.Number <> 0 THEN
Response.write Err.Description
END IF
But if the component is wrong? This method can capture errors, but how specific errors know?
We can add an error handling in the component to return an error, which can easily see more detailed error information, which helps us to troubleshoot errors.
Using Err.raise, Raise is used to generate runtime errors
Open VB6, create a new ActiveX DLL project. The engineering name is modified to FCOM, and the class name is modified to FC6
Option expedition
Public Sub showerror1 ()
ON Error Goto Errorhandle
DIM I as Double
i = 1/0
ErrorHandle:
Err.raise Err.Number, Err.Source, Err.Description
End Sub
'Generate custom errors
Public Sub showerror2 ()
Err.raise 600, "I have a defined error 600", "This is the error describing your own program"
End Sub
OK, a component is written, click on the menu -> File -> Generate the FCOM.dll file
Determine, there will be an FCOM.dll file in the directory.
test
Open Visual InterDev6.0 to generate an ASP file
<% @ Language = VBScript%>
<%
'This sentence is very important
ON Error ResMe next
Set obj = server.createObject ("fcom.fc6")
Obj.showerror1 ()
'If there is no error handling, it will generate an error interface, it is very unprofessional.
'The range from 0-512 is preserved as a system error; the range from 513-65535 can be used as a user-defined error.
'If you keep an error, the error number of the error number and page processing in the component is consistent.
IF Err.Number <> 0 THEN
Response.write "Error Message" & Err.Number & Err.Description
END IF
Response.write "
"
'If it is a user-defined error, you can process it separately on the page.
Obj.showError2 ()
IF Err.Number <> 0 THEN
IF err.number = 600 THEN
Response.write err.Number & Err.Source & Err.Description
END IF
END IF
%>
Configure a virtual directory, perform this ASP file in IE, resulting in the following:
Error message
11
Due to zero
600
Berses defined errors
600
This is a mistake to describe your own program.
