Using Math Operators (Windows Forms Applications-Microsoft Visual C++ 2008 Express Edition)

As you may already know, math operators are used to perform mathematical computations and just like any other languages, MSVC++ 2008 Express supports the following basic math operators:

(+)Addition
(-)Subtraction
(/)Division
(*)Multiplication

The following steps demonstrate these operators at work:

1. Start MSVC++ Express 2008 by clicking on the Start button, All Programs then clicking on the Microsoft Visual C++ Express Edition Start menu option.

2. Click File>New>Project. The new project dialog box will then come into view.

3. Select Windows Forms Application from the Visual Studio Installed templates, type the project name>Click Ok.
After clicking the Ok button, an IDE suited for windows forms application will then appear containing a form, a toolbox window, and a properties window.

4. Create a user interface similar to the one below:



Note: Those texts that appear beside each control are the suggested names for our form controls in this example. If you noticed I am using .Net naming convention in naming controls because it is simpler to use than Leszynski naming convention. To change the value of the name property of each control, just click each individual control then locate the name property in the properties window then assign those descriptive names in our illustration correspondingly.

5. Double-click your form then locate the following line:

#pragma endregion

6. Declare the following variables below it:

int intnum1, intnum2, intans;

Declaring these variables below the #pragma endregion line allows our variables to be available publicly and to be used by other procedures.

Your code should now appear just like this:

#pragma endregion
int intnum1, intnum2,intans;

7. Double-click the control named TimesButton,type the following:

intnum1=int::Parse(this->FnumTextBox->Text);
intnum2=int::Parse(this->SnumTextBox->Text);
intans=intnum1 * intnum2;
this->OperatorLabel->Text="*";
this->AnsLabel->Text=Convert::ToString(intans);

Your code should now appear just like this:

private: System::Void TimesButton_Click(System::Object^  sender, System::EventArgs^  e) {
intnum1=int::Parse(this->FnumTextBox->Text);
intnum2=int::Parse(this->SnumTextBox->Text);
intans=intnum1 * intnum2;
this->OperatorLabel->Text="*";
this->AnsLabel->Text=Convert::ToString(intans);
}

8. Double-click the control named DivButton,type the following:

intnum1=int::Parse(this->FnumTextBox->Text);
intnum2=int::Parse(this->SnumTextBox->Text);
intans=intnum1 / intnum2;
this->OperatorLabel->Text="/";
this->AnsLabel->Text=Convert::ToString(intans);

Your code should now appear just like this:

private: System::Void DivButton_Click(System::Object^  sender, System::EventArgs^  e) {
intnum1=int::Parse(this->FnumTextBox->Text);
intnum2=int::Parse(this->SnumTextBox->Text);
intans=intnum1 / intnum2;
this->OperatorLabel->Text="/";
this->AnsLabel->Text=Convert::ToString(intans);
}

9. Double-click the control named AddButton,type the following:

intnum1=int::Parse(this->FnumTextBox->Text);
intnum2=int::Parse(this->SnumTextBox->Text);
intans=intnum1 + intnum2;
this->OperatorLabel->Text="+";
this->AnsLabel->Text=Convert::ToString(intans);

Your code should now appear just like this:

private: System::Void AddButton_Click(System::Object^  sender, System::EventArgs^  e) {
intnum1=int::Parse(this->FnumTextBox->Text);
intnum2=int::Parse(this->SnumTextBox->Text);
intans=intnum1 + intnum2;
this->OperatorLabel->Text="+";
this->AnsLabel->Text=Convert::ToString(intans);
}

10. Double-click the control named DiffButton,type the following:

intnum1=int::Parse(this->FnumTextBox->Text);
intnum2=int::Parse(this->SnumTextBox->Text);
intans=intnum1 - intnum2;
this->OperatorLabel->Text="-";
this->AnsLabel->Text=Convert::ToString(intans);

Your code should now appear just like this:

private: System::Void DiffButton_Click(System::Object^  sender, System::EventArgs^  e) {
intnum1=int::Parse(this->FnumTextBox->Text);
intnum2=int::Parse(this->SnumTextBox->Text);
intans=intnum1 - intnum2;
this->OperatorLabel->Text="-";
this->AnsLabel->Text=Convert::ToString(intans);
}

11. Double-click the control named ClearButton,type the following:

this->FnumTextBox->Text="";
this->SnumTextBox->Text="";
this->OperatorLabel->Text="";
this->AnsLabel->Text="";

Your code will now look like this:

private: System::Void ClearButton_Click(System::Object^  sender, System::EventArgs^  e) {
this->FnumTextBox->Text="";
this->SnumTextBox->Text="";
this->OperatorLabel->Text="";
this->AnsLabel->Text="";
}

12.Double-click ExitButton, then type this->Close:

private: System::Void ExitButton_Click(System::Object^  sender, System::EventArgs^  e) {
this->Close();
}

13. Press F5 to execute your application. I will add comments to the codes above when I have time. Till then:)

Accepting and Displaying String Inputs (Windows Forms Applications-Microsoft Visual C++ 2008 Express Edition)

Visual C++ 2008 accepts and displays input in a manner that is very similar to java. In other words, the method used in accepting string data is different from the method used in accepting numeric data.
To accept a string data, and display it on your desired control, use the following syntax:

this->DestinationObjectName->Property=Convert::ToString (this-> SourceObjectName->Property);
//or simply
this->DestinationObjectName->Property= this-> SourceObjectName->Property;

Where;

1. DestinationObjectName is the name of the control where the value will be displayed.
2. SourceObjectName is the name of the control where the value will come from.

Convert::ToString is a method that converts a value inputted in a control to text or string. Using Convert::ToString method in accepting user’s input is not obligatory because all data inputted in a textbox are recognized as string.

A sample application of Convert::ToString method is demonstrated in the following steps:

1. Start MSVC++ Express 2008 by clicking on the Start button, All Programs then clicking on the Microsoft Visual C++ Express Edition Start menu option.

2. Click File>New>Project. The new project dialog box will then come into view.

3. Select Windows Forms Application from the Visual Studio Installed templates, type the project name>Click Ok.
After clicking the Ok button, an IDE suited for windows forms application will then appear containing a form, a toolbox window, and a properties window.

4. Create a user interface similar to the one shown below:



Note: Those texts that appear beside each control are the suggested names for our form controls in this example. If you noticed I am using .Net naming convention in naming controls because it is simpler to use than Leszynski naming convention. To change the value of the name property of each control, just click each individual control then locate the name property in the properties window then assign those descriptive names in our illustration correspondingly.

6. Double-Click the control named OkButton then key-in the following:

//Converts the value inputted in the StringtextBox to string
//Using Convert::ToString method is optional because
//The text entered in a textbox is already interpreted as string
this->EnteredLabel->Text=Convert::ToString(this->StringtextBox->Text); 

Your code should then appear like this:

private: System::Void OkButton_Click(System::Object^  sender, System::EventArgs^  e) {
this->EnteredLabel->Text= Convert::ToString (this->StringtextBox->Text);
}

7. Double-click ExitButton, then type this->Close(); between the open and close curly brackets. The this keyword refers to the current form while the Close() method ends the execution of the current form.

Your code should now like this:

private: System::Void ExitButton_Click(System::Object^  sender, System::EventArgs^  e) {
this->Close();
}

8. Press F5 to execute your application. If you have followed our steps carefully, our sample application should now appear without build errors.