Hey guys, I've read up on a ton of posts here and finally decided to register. So, this is my first post.
I have just started learning Visual Basic in an online class and am using Visual Basic 2010 Express.
I am NOT simply looking for someone to complete homework assignments for me; I will post my code and simply seek help in solving the errors.
That said, here's my current issue:
When the user clicks the button, I have multiple "If Then" statements to verify that the textboxes are not empty. If they are, prompt the user which box is blank and return to that box. This works just fine EXCEPT for the textboxes that are converted to Integers. Here is the code in question:
When the code is run, and either the "txtCost.Text" or "txtLife.Text" boxes are empty, it crashes and returns this error:
I'm sure this is going to be a SIMPLE fix for any of you VB gurus I've seen around here. But, go easy on me, I am learning by lots of trial and error and am just looking for some constructive feedback on what I should be doing different with my code. Thanks in advance to anyone that chimes in!
I have just started learning Visual Basic in an online class and am using Visual Basic 2010 Express.
I am NOT simply looking for someone to complete homework assignments for me; I will post my code and simply seek help in solving the errors.
That said, here's my current issue:
When the user clicks the button, I have multiple "If Then" statements to verify that the textboxes are not empty. If they are, prompt the user which box is blank and return to that box. This works just fine EXCEPT for the textboxes that are converted to Integers. Here is the code in question:
Code:
Dim description As String = txtDescription.Text
Dim purchased As String = txtPurchased.Text
Dim cost As Integer = CInt(txtCost.Text)
Dim life As Integer = CInt(txtLife.Text)
Dim straightdep As Integer
'my calculation
straightdep = CInt((cost - 0) / life)
'error checking
If txtDescription.Text = "" Then
MessageBox.Show("Description missing!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
txtDescription.Focus()
ElseIf txtPurchased.Text = "" Then
MessageBox.Show("Year purchased is missing!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
txtPurchased.Focus()
ElseIf CInt(txtCost.Text) < 0 Then
MessageBox.Show("Cost is missing!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
txtCost.Focus()
ElseIf CInt(txtLife.Text) < 0 Then
MessageBox.Show("Estimated Life is missing!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
txtLife.Focus()
Else
'populate listbox
LISTBOX CODE PURPOSELY NOT SHOWN, BUT IT WORKS FINECode:
Conversion from string "" to type 'Integer' is not valid.