Type Conversion in Calculation in VB.NET
In this article I will describe about Conversion of input values.
Introduction
Here I am going to explain why conversion i.e. "Conversion from string "" to type 'Integer' is necessary for calculation by using Microsoft Visual Basic Express 2010. Initially we take two TextBoxes in which we will enter the the integer value and take one Button, with clicking on button we are supposed to multiplication of Textbox values.
Example
If we code in Button_Click event as following:
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim a As Integer = TextBox1.Text
Dim b As Integer = TextBox2.Text
Dim z As Integer = a * b
MsgBox(z)
End Sub
In this manner although logic is correct however it will generate error.
Solution
It generates error because we are trying to assign a string value to an integer variable.
In order to do the assignment we should first determine that the conversion is possible. If the conversion is possible we can use Convert to do the conversion.
code will be as follow
Public Class Form
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim a As Integer = Convert.ToInt32(TextBox1.Text)
Dim b As Integer = Convert.ToInt32(TextBox2.Text)
Dim z As Integer = a * b
MsgBox(z)
End Sub
When we execute above code and put the values on both TextBox
When we click on Button for calculation we will find result as:
Conclusion
Replace "ToInt32" with the appropriate conversion.