Example2 for Drag & Drop Match the following type
of questions
Visual Basic 6 : Drag-n-Drop Tutorial
Visual Basic 6 - Example Two For Drag
& Drop Operation
3. Example2 for Drag & Drop
Match the following type of questions
3.1 Explains how example2 is different
from Example1
This example explains how Drag & Drop type operation
is performed for a different question type.
Dragging operation i.e. dragging the control from source
to destination is same as what is explained in Example1
that means same event procedures are used to perform Drag &
Drop operation.
In Example1 simple images are simple images are dragged
from one place to another
i.e. dragged from source & dropped on to appropriate
places(target).
But in this example a database is used to store question
and answer options.
In the front end of the application control for question,
control with blank space and also control for answer option
is, all created at runtime.
Design view of the form looks as below.
Fig6 Design view of the screen for Drag & Drop Match
cases
Fig8.shows after the controls dragged and dropped on to the
destination
In the below Fig7 each control for Question, Fill in blanks,
Answeroption
Is created at runtime based on the data in the database.
Initially in the design view all these controls visible property
set to false
Also set the index property to zero (0)
Load method is used to load the control
For example, to load the control for question based on the
data in the database following
code is written
First create the connection object
Dim con as Adodb.connection
Dim rs as Adodb.recordset
Dim I as integer
Set con = New ADODB.Connection
con.Provider="Microsoft.Jet.OLEDB.4.0"
con.Open App.path & "\" & "DragDropDemo.mdb"
'Create the recordset object
Set rs = New ADODB.Recordset
rs.Open "select * from dragdropmatch", con, adOpenStatic, adLockOptimistic, adCmdText
While rs.EOF = False
'Depending on the no. of records in database question control is created dynamically
Load lblmatqus(i)
lblmatqus(i).Caption = IIf(IsNull(rs!Question), "", rs!Question)
intrand = rsmatch1!AnsRnd
lblmatqus(i).Top = lblmatqus(i - 1).Top + lblmatqus(i - 1).Height + 100
lblmatqus(i).Left = lblmatqus(i - 1).Left
If lblmatqus(i).Caption = "" Then
lblmatqus(i).Visible = False
Else
lblmatqus(i).Visible = True
End If
I=I+1
rs.movenext
Wend
In the above example the statement IIf(IsNull(rs!Question), "",
rs!Question) checks for null value in the question field ,if
so question control with blank space is displayed or else value
of the question field from the table is displayed
To avoid the blank question control displayed, it's made
invisible if question field contains the null value and made
visible if it contains some text.
Below code explains how it works
If lblmatqus (i). Caption = "" Then
lblmatqus(i).Visible = False
Else
lblmatqus(i).Visible = True
End If
Similar technique is used to create other two controls (control
for blanks and control for answer options)
Fig7 Output Screen for Drag & Drop match cases control
before being dragged
Fig8 Output Screen for Drag & Drop match cases control
after being dragged
3.2 Database design
Field Name
Data Type
AnsSrNo
Number
Question
Memo
Answer
Memo
AnsRnd
Number
Qid
Number
In the above-mentioned table Question and also Answer for
the question is stored serially.
AnsRnd field used to display the answer option randomly.
Before displaying the answer option for candidate it's randomized
and displayed.
You can use any randomize technique to randomize the answer
or in AnsRnd field of the table DragDropMatch you can just enter
the AnsSrNo field randomly in AnsRnd field
