Several classic ASP applications _ Application Skills

1. The following code shows how to obtain x,y coordinates from a picture in the client browser on the server side, noting that the type of the input control is an image type.

<form>
<input name= "ImageMap" type= "Image" src= "imagemap.jpg" alt= "click Anywhere" >
</form>

<%imagemap.x = <%=request ("imagemap.x")
IMAGEMAP.Y = <%=request ("imagemap.y")%>


2. Using the ADODB.stream object, download the various files on the server in IE browser.

The user is prompted to download the file directly instead of the browser. Note that after copying the following code into an ASP file, do not add some non-ASP code to the page: code such as HTML and JavaScript client.


<%
'--------------------------------------------
Response.Buffer = True
Dim strFilePath, Strfilesize, strFileName
Const adTypeBinary = 1

strFilePath = "File path"
Strfilesize = ... File size, optional
strFileName = "FileName"

Response.Clear

' *******************************************8
' Need to install MDAC 2.6 or MDAC2.7 on your server
' 8*******************************************8
Set objstream = Server.CreateObject ("ADODB. Stream ")
objStream.Open
objStream.Type = adTypeBinary
objStream.LoadFromFile strFilePath

Strfiletype = LCase (Right (strFileName, 4)) ' File name extension

' Judge content-types by file name extension
Select Case Strfiletype
Case ". asf"
ContentType = "VIDEO/X-MS-ASF"
Case ". avi"
ContentType = "Video/avi"
Case ". Doc"
ContentType = "Application/msword"
Case ". zip"
ContentType = "Application/zip"
Case ". xls"
ContentType = "Application/vnd.ms-excel"
Case ". gif"
ContentType = ".. /.. /image/gif "

Case ". jpg", "JPEG"
ContentType = ".. /.. /image/jpeg "
Case ". wav"
ContentType = "Audio/wav"
Case ". mp3"
ContentType = "Audio/mpeg3"
Case ". mpg", "MPEG"
ContentType = "Video/mpeg"
Case ". rtf"
ContentType = "Application/rtf"
Case ". htm", "html"
ContentType = "Text/html"
Case ". asp"
ContentType = "Text/asp"
Case Else
' Handle all other Files
ContentType = "Application/octet-stream"
End Select

Response.AddHeader "Content-disposition", "attachment"; Filename= strFileName
Response.AddHeader "Content-length", strfilesize
Response.Charset = "UTF-8" client browser's character set UTF-8
Response.ContentType = ContentType

Response.BinaryWrite Objstream.read
Response.Flush

objStream.Close
Set objstream = Nothing

%>


3. Improve the response rate of ASP pages

On the first line of your ASP page, add:

<% EnableSessionState = False%>

This closes the session object and increases your server response rate, and the more common problem is that an HTML page contains two frames pages (at least one is an ASP page and uses a session), which makes it necessary to wait on a frames page (of course this frame page uses the session After loading, another frames page is displayed.

If you use proxy access, by default, many proxy servers do not dynamically cache ASP page content, adding the following code:

<%
Response.CacheControl = "Public"
%>


This line of code caches ASP pages on the proxy server, speeding up the response rate of the client requesting dynamic pages, and some infrequently changing ASP pages are made directly from the proxy server.

4. To know that the browser (ie, for example) will not parse return and newline characters, if you use the Response.Write method to write a line containing a carriage return and newline characters of the string to the dynamic page, the results can be imagined, you need to do is:


<%
Response.Write (Replace (Body, vbCrLf, "<br>"))
%>


Use <br> to replace carriage return and line wrapping. Note: If the carriage return and newline characters appear in the Input/textarea and other controls in the form, you do not have to do so.

5. Write IIS log with ASP code


<%
Response.appendtolog "database is being accessed"
%>


After executing this code, the following string may appear in your IIS log:
127.0.0.1,--01/01/00, 12:00:34, W3svc1,webserver,
127.0.0.1, 161342, 485, 228, 0, GET,/somefile.asp, database is being accessed

Note: Because the contents of the log file are separated by commas, the log content written should avoid using commas.

6. How to access the MDB database file on a remote computer

If you use an ODBC connection (DSN method or otherwise) to an MDB file on a remote computer, this will produce an error:
Microsoft OLE DB Provider for ODBC Drivers error ' 80004005 '
The general meaning is that the file may be accessed by another user or without sufficient privileges.

Here are two ways to avoid this error:

Way A. Using the DAO engine to access


Dim File, Conn, RS
Const ReadOnly = False

File = "\\server\share\file.mdb"
Set Conn = CreateObject ("DAO. dbengine.35 "). Workspaces (0). OpenDatabase (file,,readonly)
Set RS = Conn.openrecordset (SQL)


Mode B. ADO + Jet OLE DB provider method


Dim Conn, RS
Set Conn = CreateObject ("ADODB. Connection ")
Conn.provider = "Microsoft.Jet.OLEDB.4.0"
Conn.Open "\\server\share\file.mdb"
Set RS = Conn.execute (SQL)


Make sure that you have sufficient access rights to access the MDB file on the remote computer when you run the ASP page, before you can access the MDB file

Log on to the remote computer and add the following code


Set UM = CreateObject ("Usermanager.server")
Um. LogonUser "Account", "Password", "Domain"
...
Open Database
...
Um. RevertToSelf