Packaging | data | database | Strings Nowadays, most of the development Web applications are using the Browser/server mode, while in the B/s Application development field, Microsoft's iis/asp combination has the powerful function, the good expansion ability and the good compatibility with other Microsoft products, Pop up quickly. ASP with its simple and easy to learn, powerful and win the love of the vast number of programmers, most of the domestic web sites are the use of ASP architecture. When we use ADO to access a database, we sometimes write the connection string explicitly in the. ASP file, this is obviously not very safe, it is easy to be a person with ulterior motives to obtain passwords, database names and other information. For data security, we can write our own component to encapsulate the string that accesses the database, and then call it on the Global.asa file or. asp.
First, let's take a step-by-step to create a component:
Start vb6.0 new-->activex DLL project. Click the Project--> Reference and select both Microsoft Active Server Pages Object library and Microsoft ActiveX Data Objects 2.1 library. Change the name of the class module to wenconnection. Change the name of the project to Wenadodb. Save the project file Wenadodb.vbp and the class file WENCONNECTION.CLS. Specific approach: 1 Select "Project"-> "Reference" to enter the reference user selection interface as shown in Figure 1, in the Available References check box, select Microsoft Active Server Pages Object library and Microsoft ActiveX Data Objects 2.1 Library "two items.
Figure 1
2 Select "Engineering"-> "Engineering properties" into the Project property settings interface, select the "General" page, in the "Project type" drop-down box, choose "ActiveX DLL", in the Project name input box, enter the project name "Wenadodb", as shown in Figure 2.
Figure 2
3) and select the "Compile" page, select "Code size Optimization", as shown in Figure 3.
Figure 3
So far, we have completed the basic settings of the new project's properties, references, and so on.
Second, we'll write code in the class Wenconnection.cls:
1 The first thing to declare variables:
Private Wenscriptingcontext as ScriptingContext
Private Wenapplication as Application
Private Wenrequest as Request
Private Wenresponse as Response
Private Wenserver as Server
Private Wensession as session
2 in order to use an ASP's built-in object in the Wenconnection class, you must write a onstartpage child function in this class. That's because whenever a user accesses an ASP file with this component, IIS sends the ScriptingContext to our object and invites us to use it. This scriptingcontext includes all ASP methods and attributes, which gives us the ability to access all ASP objects.
Public Sub OnStartPage (Passedscriptingcontext as ScriptingContext)
Set Wenscriptingcontext = Passedscriptingcontext
Set wenapplication = wenscriptingcontext.application
Set wenrequest = wenscriptingcontext.request
Set Wenresponse = Wenscriptingcontext.response
Set Wenserver = Wenscriptingcontext.server
Set wensession = wenscriptingcontext.session
End Sub
Now that we use the OnStartPage function to create the object, we use the OnEndPage function to release the object:
Public Sub OnEndPage ()
Set Wenscriptingcontext = Nothing
Set wenapplication = Nothing
Set wenrequest = Nothing
Set Wenresponse = Nothing
Set Wenserver = Nothing
Set wensession = Nothing
End Sub
Next, define two functions Rsresult () and DataSource ():
Public Function Rs (strSQL as String) as Recordset
Dim oconn as Connection
Dim ORs as Recordset
Dim strconnstring as String
strconnstring = "Driver={sql server};server=servername;uid=sa;pwd=;" & _
"Database=databasename"
oConn.Open strconnstring
Ors.activeconnection = oconn
Strsql= "SELECT * FROM tablename"
oRS.Open strSQL, oconn, 1, 3
Set Rs = ORs
End Function
Public Function datasourceconnection () as Variant
Datasourceconnection = "Driver={sql server};server=servername;uid=sa;pwd=;d atabase=databasename"
End Function
Third, save the project name is Wenadodb.vbp and save class name is Wenconnection.cls, then click "File"-> "Generate WenADODB.DLL" compile into Dynamic Connection library file. VB in the compilation of dynamic connection library files are also registered in the registration table, if you want to register the component on another machine, please use the following instructions to register or reverse registration:
Regsvr32 x:\ path \wenadodb.dll x:\ path \ disk character and path for WenADODB.dll file
regsvr32/u x:\ Path \wenadodb.dll parameter U for anti-registration
The example of invoking the WenADODB.dll component in the ASP file.
<%
Set conn=server.createobject ("wenadodb.wenconnection") ' invokes the component to create an object instance
Objconn=conn.datasourceconnection ()
Application ("strconn") =objconn
Set Rs=server.createobject ("ADODB. Recordset ")
Sql= "SELECT * FROM tablename ORDER by ID DESC"
Rs.Open sql,application ("strconn"), 1,3
%>
<table align= "Center" border= "1" >
<%
If Rs.bof and rs.eof then
Response.Write "There is no data for the moment. "
Else
Do as not rs.eof
%>
<tr width=100%>
<TD width=50%><%=rs ("Field1")%></td><td width=50%><%=rs ("Field2")%></td>
</tr>
<%
Rs.movenext
Loop
End If
Rs.close; Set rs=nothing
%>
</Table>
V. Summary
We're just knitting.
