TabControl

1
TabControl

• TabControl is used to show multiple pages on the
  same form.

2
TabControl

• Use the collection editor to add tabpages

3
DateTimePicker Substract

• Getting the difference between 2 dates.
• date1 Me.DateTimePicker1.Value.Date
• date2 Me.DateTimePicker2.Value.Date
• Use the subtract method to get the difference
  between date1 and date2
• numdays date2.Subtract(date1).TotalDays

4
String Methods

• Part of a string
• E.g. string1 dont kill me
• String2 string1.substring(5) ? starting at 5th
  position
• String2 becomes kill me
• String2 string1.substring(5,4) ?start at 5th ,
  take 4 chars.
• String 2 becomes kill

5
String Methods Indexof

• To find a position in the string, e.g. where is
  in abc 100. Use the indexof method
• ix string1.indexof() Now is the 4th
  position.
• To get 100, we use
• String2 string1.substring(ix,3)
• Where ix is the start position and 3 is the
  number of characters to get.

6
String Trim method

• To remove blanks (spaces) from inputs,
• Use
• String1 textbox1.text.trim().
• E.g.
• Trim removes the spaces before and after 100.

___100___
7
Split function

• E.g s1 1,1,0,1,0,1
• We dim AA(5) as string
• AA Split (s1, ,)
• 1,1,0,1,0,1
• AA
• S1 will be split into the 6 elements of AA using
  the ,.

8
Join Function

• Join is the reverse of Split
• S1 Join (AA, )
• Here, AA is
• S1 becomes 110101

9
Multiforms (contd)

• In form1

Form2
Dim f2 as New form2 f2.showdialog()
Note form1 controls form2, and form1 can see the
labels, textboxes in form2. Form2 cannot see
form1. Do not, in form2, NEW a form1.
10
Forms owner

• When in form1, you new form2, form1 owns form2.
• In order to allow form2 to see form1s labels,
  use the owner property.
• Make form2s owner equals to form1

Form1 form2
Dim f2 as New form2 f2.owner me Label1.text
111 f2.showdialog()
Dim f1 as form1 Not new Sub form_load ( f1
me.owner me is form2 username f1.
Label1.text
11
Array of Controls

• Instead of referencing checkbox1,checkbox2,
  Checkbox3. You can dim an array of checkboxes.

12
Array of Checkboxes

• First dim an array CK ( ) as checkbox.
• CK(i) New Checkbox ? Note new creates the
  checkbox
• Set the location of the checkbox.
• Add the checkbox-i to the form using
• Me.controls.add(CK(i))
• Now the checkboxes can be access as CK(i).

13
StreamWriters

• Dim fout As StreamWriter
• fout New StreamWriter (badcourt1)
• fout.writeline(0,1,0,0,0,0,1,1,1)
• Sub closefile_click
• fout.close()
• End sub

14
StreamReaders

• StreamReaders
• Dim fin As StreamReader
• fin New StreamReader (badcourt1)
• Dim AA(5) as string
• Dim line as string
• Do While (fin.Peek() ltgt -1)
• line fin.ReadLine()
• AA Split(line, ",")
• Loop