Visual Basic

Re: Determine whether there is select item in the list

8-Aug-07 0:25

Thank you for your comment. But I do not want to know the selection mode. What i want is whether any item in my listbox is select or not. My list box selection mode is set to select only one item only.

Thank you for your support Smile | :)

Luc Pattyn8-Aug-07 0:29

Luc Pattyn

8-Aug-07 0:29

as I said it depends on the selectionmode which two of the four properties I mentioned
you should use.

Luc Pattyn [Forum Guidelines] [My Articles]

Re: Determine whether there is select item in the list

Tom Deketelaere8-Aug-07 1:14

Re: Determine whether there is select item in the list

8-Aug-07 1:14

if you want to know wheter or not there is a selected item:

if listbox.selecteditems.count = 0 then
'nothing is selected
else
'something is selected
end if

if you want to know wich item is selected
when there can be more than 1:
listbox.selecteditems 'contains all the selected items

when only 1 is possible:
listbox.selecteditem

if you want to know the index of the selected item
when there can be more than1:
listbox.SelectedIndices 'contains all the indeces for all the selected items

when only 1 is possible:
listbox.selectedindex

Mekong River8-Aug-07 15:36

Re: Determine whether there is select item in the list

8-Aug-07 15:36

Thank you for your detail explaination.

koolprasad20038-Aug-07 1:13

koolprasad2003

8-Aug-07 1:13

hello frnd,

check listbox1.selectedItem.count > 0

regards,
koolprasad2003 Smile | :)

Be a good listener...Because Opprtunity knoughts softly...N-Joy

Re: Determine whether there is select item in the list

Mekong River8-Aug-07 15:37

Re: Determine whether there is select item in the list

8-Aug-07 15:37

Thank you for your support.

The ANZAC8-Aug-07 1:51

The ANZAC

8-Aug-07 1:51

in a listbox if no item is selected the selectedindex = -1 so:

if me.listbox1.selectedindex = -1 then<br />
'nothing is selected<br />
end if

Please check out my articles:
The ANZAC's articles

Re: Determine whether there is select item in the list

Mekong River8-Aug-07 15:35

can i create annotation in picture box using vb.net? [modified]

8-Aug-07 15:35

Thank you, this is what I need.

babusat7-Aug-07 22:28

babusat

7-Aug-07 22:28

i want to create annotation (rectangle box with transparent) with selection of user mouse, like that i want to select all parts of the image and save the coordinates using picture box tool

please help

regards

sathish

-- modified at 7:06 Wednesday 8th August, 2007

how to create a control

eyes20077-Aug-07 22:22

7-Aug-07 22:22

hello there

i just begun to create my control,
when i create a class project, add the references. when i write

private sub new() (and press enter)

end sub

the code looks like something like that

when i take customcontrol and do the same the code is

private sub new()
' This call is required by the Windows Form Designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
end sub

what m i missing in the class file

then

i give the mybase.backcolor

that will show the control's color and its fine

but now i need to draw some drawing on that "mybase" how can i do that to give my control a shape and also i need to draw an another drawing on that control that will move on to that control vertically or horizontaly.

does someone knows the documentation about that or any kind of help

thanx in advance

Tom Deketelaere7-Aug-07 23:24

7-Aug-07 23:24

you aren't missing anything in the class file
a constructor in a class file doesn't contain the initializecomponent because it has no controls to initialize

the initializecomponent in a customcontrol or windows form is located in the designer and creates,sets property's of the controls you put on to that customcontrol or windows form.

since a class doesn't contain controls it is not needed

to give you'r control a shape look into the region property

Dim arrRegion As ArrayList = 'fill array with points
            If Not arrRegion.Count = 0 Then
                Dim pntRegion(arrRegion.Count) As Point
                pntRegion = arrRegion.ToArray(GetType(Point))
                Dim c As New System.Drawing.Drawing2D.GraphicsPath
                c.ClearMarkers()
                c.AddCurve(pntRegion)
                If Not c Is Nothing Then
                    Me.Region = New Region(c)
                End If
            End If

with this you can give you're control any shape you want

for the drawing that has to move I suggest you create a second customcontrol (with its region adjusted) place it on you'r first and adjust the position when needed

eyes20078-Aug-07 0:16

8-Aug-07 0:16

can u tell me something about

Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)

end sub

or

Protected Overloads Overrides Sub OnPaint(ByVal e As PaintEventArgs) MyBase.OnPaint(e)

end sub

what should i use in my program

both gives an error when i use them in class file

both gives no error when i use them in customcontrol file

where should i write the code, in my function or the one of them as on up

thnx

Tom Deketelaere8-Aug-07 1:09

8-Aug-07 1:09

well if you want to set the region of the control you can do that in the load of the control

if you want to draw something on the control (using the graphics) you should be able to use

Protected Overloads Overrides Sub OnPaint(ByVal e As PaintEventArgs)

'you're code comes here

        MyBase.OnPaint(e)
    End Sub

or for a custom control

Private Sub ctrlLineHorizontal_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint

End Sub

keep in mind that the code you place inside the paint methode/event will me run everytime you're control repaints and this happens when you
move the control (at run time) (or parent control/form)
when another window is placed on top of it and then you return to the control
when you resise the control (or parent control/form)

so it would be wise to keep the code inside the paint methode/event to an absolute minimum

eyes20078-Aug-07 2:50

8-Aug-07 2:50

how can i set the region of the control at load of the control
did u mean the load event of the control (the control does not have the load event)

second

Protected Overloads Overrides Sub OnPaint(ByVal e As PaintEventArgs)
'you're code comes here
MyBase.OnPaint(e)
End Sub
r u confirmed about the position of the ('you're code comes here) in the code

because in all examples i saw the position of ('you're code comes here) is

Protected Overloads Overrides Sub OnPaint(ByVal e As PaintEventArgs)
MyBase.OnPaint(e)
'you're code comes here
End Sub

can u plz give me an example of that what i m trying to do

Tom Deketelaere8-Aug-07 3:11

Re: how to create a control [modified]

8-Aug-07 3:11

1: normally every usercontrol has a load event (doubleclick on the control should automaticly place you in the code of the event)(otherwise you can select the event in the 2 comboboxes just above the code(in code view) first comobox: (usercontrol1 events) second combobox: load)

2: I'm not sure but I don't think the placement of the mybase.onpaint(e) matters

example (kryptic)

public sub load event
me.region = new region... 'see previous posted code
end sub

Protected Overloads Overrides Sub OnPaint(ByVal e As PaintEventArgs)
MyBase.OnPaint(e)
e.graphics.drawline(...)
e.graphics.drawstring(...)
'...
End Sub

if you give me a more detaild description of what exactly it is that you want I could give you more detailed code
what needs to be drawn?
what shape is you're control?
when does the movement happen (all the time or when you tell it too)?
...

eyes20078-Aug-07 4:14

8-Aug-07 4:14

what i need to draw is a ruler control
which contain
1. a background.
2. some number on that control at specified distance like inches.
3. some vertical lines just like the normal scale has.
4. two slider's one is upper and the second one for lower usually as in the any application which is used to increase or decrease the page margin.
5. these slider's should be able to move horizontally or vertically on the ruler

i have tried it to write in class, customecontrol, usercontrol also

that some thing i worried about. Confused | :confused:

any suggestion is appreciated

thnx

help everyone

Tom Deketelaere8-Aug-07 21:33

8-Aug-07 21:33

1. I'm asuming this is already done (me.backcolor=...)
2. (simple example)

Dim i As Integer = 0
        For i = 0 To 10
            e.Graphics.DrawString(i, New Font("arial", 8), Brushes.Black, i * 10, 5)
        Next

3. (simple example)

Dim i As Integer = 0
        For i = 0 To 10
            e.Graphics.DrawLine(Pens.Black, i * 10 + 5, 0, i * 10 + 5, 10)
        Next

4. create 2 new controls and give them the shape of an arrow with the region property
5. I'm boxing something together for this and get back to you

1 can be done in the load of you're control or in a property
2 and 3 are best done in the paint event

Tom Deketelaere8-Aug-07 22:37

8-Aug-07 22:37

I've created a very simple example but it is to much code to post here
Can you provide me with an email so I can send it to you
You can mail me directly from this site (choose email instead of reply)

eyes20079-Aug-07 1:22

9-Aug-07 1:22

i think u already had my mail id

i sent a mail to you check it out.

again thnx

help everyone

eyes20079-Aug-07 19:39