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hi! i'm new to vb .net..i want to calculate a power, i want to do it in a function..i'm having a hard time with arguments and parameters as well as with the return value.
please help! i have 2 text boxes for accepting inputs for base and exponent.
Public Class Power
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim base, exp As Integer
base = Val(text1.Text)
exp = Val(text2.Text)
MessageBox.Show("Power: " & Power(base, exp)) //how about this??
End Sub
Function Power(ByVal x As Integer, ByVal y As Integer)
Dim pow, i As Integer
Select Case y
Case 1
MessageBox.Show(x & " raised to " & y & " is 1")
Case 0
MessageBox.Show(x & " raised to " & y & " is 0")
End Select
For i = 2 To y
Return pow = pow * x //is this correct??
i += 1
Next
Return ??what/how??
End Function
End Class
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Have you tryed:
dim Number as integer = 2
dim Power as integer = 5
dim x as integer = Number ^ Power
Alexei Rodriguez
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trying to do the calculation inside a loop, not using nay math method or ^..
thank you!
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ay3ssah wrote: Function Power(ByVal x As Integer, ByVal y As Integer)
You should specify the return type of the method, otherwise the return type will be Object.
Function Power(ByVal x As Integer, ByVal y As Integer) As Integer
ay3ssah wrote: Case 1
MessageBox.Show(x & " raised to " & y & " is 1")
That is not correct. x raised to 1 is x, not 1.
ay3ssah wrote: Case 0
MessageBox.Show(x & " raised to " & y & " is 0")
That is not correct. x raised to 0 is 1, not 0.
ay3ssah wrote: Return pow = pow * x //is this correct??
No, that is not correct. As you don't initialise the pow variable, it will be zero from start. Anything times zero is still zero, so the final result will always be zero.
ay3ssah wrote: i += 1
If you increment the loop variable in the loop, that will have the same effect as having a loop with step 2. The For...Next statement increments the loop variable automatically.
ay3ssah wrote: Return ??what/how??
Return pow
Despite everything, the person most likely to be fooling you next is yourself.
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whoaa!!! i did all of that but i erased it..hehe
did i mention that the calculation should be done in a loop? not with Math.pow or ^ sign..
is it ok to return one argument even if there are two parameters?
thank you so much! il try all of that later..
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You can only return one value from a function, unless you use byref parameters or you create your own class or structure, or you return an array
Alexei Rodriguez
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Hi
im using vs2005, try this
************************************
dim Out as double
out = Math.Pow(Number,Power to raise by)
ie. out = math.Pow(5,2)
out = 25
**************************
Anoop
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i want to use looping instead of ^ and math.pow..thanks!
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How do I write code for?
Catch Format Exception (invalid input)
This is for a program that only has you selecting from 0-3 and anything else is an invalid input.
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You only want the user to be able to enter 0, 1, 2, or 3 in a text box?
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That is correct or they get a format exception error.
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In the textbox's KeyPress event, check to make sure that the character entered is either a 0, 1, 2, or a 3. If it is, then set e.Handled = True. If not, then you can raise the error that you want to raise and set e.Handled = False.
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Thanks, but I have to use a try catch statement for this one.
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Hello everybody,
having to work with an uncommon image format (dpx, a bitmap which is not supported by GDI+) I tried a few libraries which support the format as well as Visual basic. My knowledge of VB is still too little to implement the new image object successfully and show a dpx-picture in a picture box.
Maybe somebody can help me with the basics a bit? In the particular case, I'm using a free graphics Library used by the famous XnView. My following code throws an error saying that the COM-Object couldn't be converted:
Imports GflAx
Private MyImage As GflAx.GflAx
Public Class clsXn
Public Sub ShowMyImage(ByVal fileToDisplay As String, ByVal xSize As Integer, _
ByVal ySize As Integer)
' Sets up an image object to be displayed.
If (MyImage IsNot Nothing) Then
MyImage.Dispose()
End If
' Stretches the image to fit the pictureBox.
frmHead.pbox.SizeMode = PictureBoxSizeMode.StretchImage
MyImage = New GflAx.GflAx
MyImage.LoadBitmap(fileToDisplay)
frmHead.pbox.ClientSize = New Size(xSize, ySize)
frmHead.pbox.Image = MyImage '<------- ERROR THROWN
End Sub
end class
The function is called from the form with
Private Sub btnTestXn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnTestXn.Click
Dim Xn As New clsXn()
Xn.ShowMyImage("D:\Test\pic1041.dpx", 192, 108)
End Sub
What did I forget or how can I solve the issue?
I'm a bit afraid that I ran into a GDI+ issue that only accepts certain formats, but I thought using the third party object this would have been solved.
Thanks for any advice,
Michael
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Your code is trying to convert an object of type GflAx to a .NET Image object. That's not going to work. The GflAx object has to expose some method to return an Image object. You're best source of information on this would be the people or forums that created/deal with this image library.
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Thank you, Dave.
I've tried the only two methods from the help file which seemed to make sense (object.LoadBitmap and object.GetPicture), with similar result. As you suggest I'll get in touch with the developers.
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Yeah, both of those methods tell the object to load a file into itself. There has to be a different method or property of that object that returns the image itself, in a format that can be used by the Image class.
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In my windows form there are few comboBox.They are bind with database. But when I run the form and select any comboBox and backspace or press delete button then comboBox delete.But I don't like so. How to avoid this.I like to behave comboBox like webpage. Such as when I click in any comboBox item name(not in black triangle-arrow), comboBox should open the item list.
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Saam_cse wrote: But when I run the form and select any comboBox and backspace or press delete button then comboBox delete.
If the combobox is being removed from the form, you're still in the designer, not the running application. You cannot just click on a control and delete it unless you provide the code to do so.
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ok see this, the items on the Combobox will not be edited.
comboBox1.Items.Add("First");
comboBox1.Items.Add("Second");
comboBox1.Items.Add("Third");
comboBox1.Items.Add("Forth");
comboBox1.DropDownStyle = ComboBoxStyle.DropDownList;
Hope this is what you want
Vuyiswa Maseko,
Sorrow is Better than Laughter, it may Sadden your Face, but It sharpens your Understanding
VB.NET/SQL7/2000/2005
http://vuyiswamb.007ihost.com
http://Ecadre.007ihost.com
vuyiswam@tshwane.gov.za
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Set its DropDownStyle property to DropDownList.
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Hi friends,
I have an interesting problem in vb.net. And I am struggling to get a solution for this..m trying for the past 3days.. It’s to calculate moving average for the inputs given by the user..
The following are the steps..
1, get 2user inputs in textbox(1st input is number is periods, 2nd is moving range)
2, after getting both the user inputs, the user will click on an input button which must dynamically generate rows for the number of periods given by the user as well as a calculate button must appear dynamically.
3, the user again inputs the values for all the dynamically generated rows and when by pressing calculate button, the moving average for the given moving range must appear in another column
Im half way through and I have attached my progress here.. I would greatly appreciate if u complete it for me.. thanks in advance
Partial Public Class _Default
Inherits System.Web.UI.Page
Protected Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim TxtDyn1 As TextBox()
Dim TxtDyn2 As TextBox()
Dim TxtDyn3 As TextBox()
Dim TxtDyn4 As TextBox()
Dim numofper As Integer
Try
'to check the textbox for empty
If Not TextBox1.Text Is String.Empty Then
numofper = TextBox1.Text
ReDim TxtDyn1(numofper)
ReDim TxtDyn2(numofper)
ReDim TxtDyn3(numofper)
ReDim TxtDyn4(numofper)
Else
Exit Sub
End If
'To create the dynamic text box and add the controls to panel
For i As Integer = 0 To numofper - 1
TxtDyn1(i) = New TextBox
Panel1.Controls.Add(TxtDyn1(i))
Next
For j As Integer = 0 To numofper - 1
TxtDyn2(j) = New TextBox
Panel2.Controls.Add(TxtDyn2(j))
Next
For k As Integer = 0 To numofper - 1
TxtDyn3(k) = New TextBox
Panel3.Controls.Add(TxtDyn3(k))
Next
For l As Integer = 0 To numofper - 1
TxtDyn4(l) = New TextBox
Panel4.Controls.Add(TxtDyn4(l))
Next
Dim mybutton As New Button (THIS S NOT WORKING )
mybutton.Text = "button 2"
AddHandler mybutton.Click, AddressOf button2.click
Me.Controls.Add(mybutton)
Catch ex As Exception
MsgBox("Enter a valid Number")
End Try
End Sub
End Class
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You've done nothing but create arrays of controls. There is no code to generate any moving average or anything else. You're missing the meat of the application. Forget about the User Interface stuff for now and create the code to generate the data you need. This is going to need some kind of input to do and this need to going to dictate how you do the UI. You may even end up scraping everything you have so far to do this.
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hi .. i am new to vb.net and i have a problem in maintaining values in two button events.. so pls help me.. i have just added some code to that.. please correct them and help me completing.. im struggling without enough source to refer..
Partial Public Class _Default
Inherits System.Web.UI.Page
Dim textdynamic1 As New ArrayList()
Dim textdynamic2 As New ArrayList()
Dim textdynamic3 As New ArrayList()
Dim textdynamic4 As New ArrayList()
Dim TxtDyn1 As TextBox()
Dim TxtDyn2 As TextBox()
Dim TxtDyn3 As TextBox()
Dim TxtDyn4 As TextBox()
Dim k As Integer
Dim a As Integer
Dim b As Integer
Dim l As Integer
Dim numofper As Integer
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Try
'to check the textbox for empty
If Not TextBox1.Text Is String.Empty Then
numofper = TextBox1.Text
ReDim TxtDyn1(numofper)
ReDim TxtDyn2(numofper)
ReDim TxtDyn3(numofper)
ReDim TxtDyn4(numofper)
Else
Exit Sub
End If
'To create the dynamic text box and add the controls to panel
For i As Integer = 0 To numofper - 1
TxtDyn1(i) = New TextBox
Panel1.Controls.Add(TxtDyn1(i))
textdynamic1.Add(textdynamic1)
Next
For j As Integer = 0 To numofper - 1
TxtDyn2(j) = New TextBox
Panel2.Controls.Add(TxtDyn2(j))
textdynamic2.Add(textdynamic2)
Next
For k As Integer = 0 To numofper - 1
TxtDyn3(k) = New TextBox
Panel3.Controls.Add(TxtDyn3(k))
textdynamic3.Add(textdynamic3)
Next
For l As Integer = 0 To numofper - 1
TxtDyn4(l) = New TextBox
Panel4.Controls.Add(TxtDyn4(l))
textdynamic4.Add(textdynamic4)
TxtDyn4(l).Enabled = False
Next
Catch ex As Exception
MsgBox("Enter a valid Number")
End Try
End Sub
Private Sub Button2_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button2.Click
Dim nval As Integer
nval = TextBox2.Text
For Each b As Integer In textdynamic4
Do
For Each a As Integer In textdynamic3
a += TxtDyn3(k).Text
Next
Loop While k <= nval
TxtDyn4(l).Text = a / nval
Next
End Sub
End Class
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Please help me to disable / hide Start Orb in Windows Vista using Visual Basic 6 (not VB.Net, VB2005 or VB2008 or C# or C++ !!!).
Such solution on this website was proposed by Simon B. using VB2008, however I need it for Visual Basic 6.
Thanks in advance for your help.
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