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Open your Visual Studio or Visual C# Express Edition and create a new project. Set its type to Windows Forms Application and set its name to CalculatorApp. You should see the main form on the workspace as follows: Step 2 Change the form text property to Calculator, because we don’t want our application to have the title Form1 when. Creating a Calculator Visual Studio C#: This Instrucable will guide you through creating a basic calculator application in C# using Microsoft's Visual Studo development software. Visual Studio is a form of development software made by Microsoft to help developers create programs more eas.
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The calculator above was created after I did some work crunching out the code and searching the Internet for solutions where I got stuck. Thanks to the generosity of the programming fraternity, I managed to come up with something to the best of my amateur ability. I still got stuck with one portion of the code, which I will indicate later.
Following is the full code for this program, and I call it: QuickCalc.
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First and foremost, arrange all the necessary command buttons and a textbox onto a Form. For the textbox, I set it to read-only, and text to “0” (zero, not the letter O), named it txtInput.
Next, some essential global declarations.
| 1. | ‘Variables to hold operands. |
| 2. | Private dblValue1 As Double |
| 3. | Private dblValue2 As Double |
| 4. | ‘Variable to hold temporary values. |
| 5. | Private dblTemp As Double |
| 6. | ‘True if “.” is used, otherwise false. |
| 7. | Private blnDecimalPoint As Boolean |
| 8. | Private blnInputStatus As Boolean |
| 9. | ‘Variable to hold Operator. |
| 10. | Private strCalculate As String |
Next, the code for Number buttons 1 – 9.
| 1. | If (blnInputStatus AndAlso txtInput.Text <> “0”) Or blnDecimalPoint Then |
| 2. | txtInput.Text += cmd1.Text |
| 3. | Else |
| 4. | txtInput.Text = cmd1.Text |
| 5. | blnInputStatus = True |
| 6. | End If |
The above code is for button number 1. For 2 to 9, simply change the cmd number to the respective button number.
Next, the code for Number button 0.
| 1. | If blnInputStatus Then |
| 2. | ‘To prevent multiple zeroes from appearing if 0 is the first digit. |
| 3. | If txtInput.Text.Length >= 1 AndAlso txtInput.Text <> “0”Then |
| 4. | txtInput.Text += cmd0.Text |
| 5. | ‘This is to allow 0 to be added after the decimal point. |
| 6. | ElseIf blnDecimalPoint Then |
| 7. | txtInput.Text += cmd0.Text |
| 8. | End If |
| 9. | End If |
Next, the code for Decimal button.
| 1. | ‘To make sure that no decimal point has already been input. |
| 2. | If Not blnDecimalPoint Then |
| 3. | ‘For values > 0 but < 1. |
| 4. | If txtInput.Text.Length < 1 Then |
| 5. | txtInput.Text = “0.” |
| 6. | Else |
| 7. | txtInput.Text += “.” |
| 8. | End If |
| 9. | |
| 10. | blnInputStatus = True |
| 11. | ‘To ensure only one decimal point per calculation. |
| 12. | blnDecimalPoint = True |
| 13. | End If |
Next, the code for the Addition operator.
| 1. | If txtInput.Text.Length <> 0 Then |
| 2. | ‘Check the value of the function flag. |
| 3. | If strCalculate = String.Empty Then |
| 4. | ‘Assign the value in the input box to the holder. |
| 5. | dblValue1 = CType(txtInput.Text, Double) |
| 6. | txtInput.Text = “0” |
| 7. | Else |
| 8. | ‘Call the CalculateTotals method. |
| 9. | CalculateTotals() |
| 10. | End If |
| 11. | |
| 12. | ‘Assign a value to the function flag. |
| 13. | strCalculate = “Add” |
| 14. | |
| 15. | ‘Toggle the decimal flag. |
| 16. | blnDecimalPoint = False |
| 17. | End If |
The code for the Subtraction, Multiplication, and Division operators are almost identical, except that you need to change the value assigned to the function flag – Subtract, Multiply, Divide – respectively.
Next, the code for Equal button.
| 1. | If txtInput.Text.Length <> 0 Then |
| 2. | CalculateTotals() |
| 3. | strCalculate = String.Empty |
| 4. | blnDecimalPoint = False |
| 5. | End If |
Next, the code for the Exponential button.
| 1. | If txtInput.Text.Length <> 0 Then |
| 2. | If strCalculate = String.Empty Then |
| 3. | dblValue1 = CType(txtInput.Text, Double) |
| 4. | txtInput.Text = “0” |
| 5. | Else |
| 6. | CalculateTotals() |
| 7. | End If |
| 8. | strCalculate = “Exponential” |
| 9. | blnDecimalPoint = False |
| 10. | End If |
Visual Basic Simple Calculator Code
Next, the code for the Square Root button.
| 1. | If txtInput.Text < “0”Then |
| 2. | MsgBox(“The root of a negative number is undefined!”, 0, “WARNING”) |
| 3. | Exit Sub |
| 4. | End If |
| 5. | |
| 6. | If txtInput.Text.Length <> 0 Then |
| 7. | dblTemp = CType(txtInput.Text, Double) |
| 8. | dblTemp = System.Math.Sqrt(dblTemp) |
| 9. | txtInput.Text = CType(dblTemp, String) |
| 10. | blnDecimalPoint = False |
| 11. | End If |
Next, the code for the Reciprocal button.
| 1. | If txtInput.Text.Length <> 0 Then |
| 2. | dblTemp = CType(txtInput.Text, Double) |
| 3. | dblTemp = 1 / dblTemp |
| 4. | txtInput.Text = CType(dblTemp, String) |
| 5. | blnDecimalPoint = False |
| 6. | End If |
Next, the code for the Positive/Negative button.
| 1. | If txtInput.Text.Length <> 0 Then |
| 2. | dblTemp = CType(txtInput.Text, Double) |
| 3. | dblTemp *= -1 |
| 4. | txtInput.Text = CType(dblTemp, String) |
| 5. | End If |
Next, the code for the Clear All (C) button.
| 1. | txtInput.Text = “0” |
| 2. | dblValue1 = 0 |
| 3. | dblValue2 = 0 |
| 4. | strCalculate = String.Empty |
| 5. | blnDecimalPoint = False |
Next, the code for the Clear Entry (CE) button.
| 1. | txtInput.Text = “0” |
| 2. | blnDecimalPoint = False |
Visual Basic Calculator Project
Next, the code for the Backspace button.
| 1. | ‘Declare locals needed. |
| 2. | Dim str As String |
| 3. | Dim intNumbers As Integer = txtInput.Text.Length |
| 4. | |
| 5. | If txtInput.Text.Length = 1 Or (txtInput.Text.Length = 2 AndAlso |
| 6. | txtInput.Text.StartsWith(“-“)) Then |
| 7. | txtInput.Text = “0” |
| 8. | Exit Sub |
| 9. | End If |
| 10. | |
| 11. | If txtInput.Text.Length > 0 Then |
| 12. | ‘Get the next to last character. |
| 13. | str = txtInput.Text.Chars(txtInput.Text.Length – 2) |
| 14. | ‘Check if it’s a decimal. |
| 15. | If str = “.”Then |
| 16. | ‘If it is, then toggle the blnDecimalPoint flag. |
| 17. | blnDecimalPoint = False |
| 18. | txtInput.Text = txtInput.Text.Remove(intNumbers – 2) |
| 19. | Exit Sub |
| 20. | End If |
| 21. | txtInput.Text = txtInput.Text.Remove(intNumbers – 1) |
| 22. | End If |
Finally, the CalculateTotals procedure.
| 1. | dblValue2 = CType(txtInput.Text, Double) |
| 2. | Select Case strCalculate |
| 3. | Case“Add” |
| 4. | dblValue1 += dblValue2 |
| 5. | Case“Subtract” |
| 6. | dblValue1 -= dblValue2 |
| 7. | Case“Multiply” |
| 8. | dblValue1 *= dblValue2 |
| 9. | Case“Divide” |
| 10. | If dblValue2 = 0 Then |
| 11. | MsgBox(“You cannot divide by 0!”, 0, “WARNING”) |
| 12. | Exit Sub |
| 13. | End If |
| 14. | dblValue1 /= dblValue2 |
| 15. | Case“Exponential” |
| 16. | dblValue1 ^= dblValue2 |
| 17. | End Select |
| 18. | txtInput.Text = CType(dblValue1, String) |
| 19. | blnInputStatus = False |
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Above is the code for this calculator program.
!PROBLEM!
However, there is an area which I have some niggling issues with.
1. For the + – * / and ^ operators, if I were to click on one of them multiple times after I input the first value, they will go performing the operation on their own without me entering the second value. How do I stop this from happening?