Learn to Create Basic Windows Forms in C#: A Guide for HNDIT Students

Objective: Create a calculator that performs basic arithmetic operations (addition, subtraction, multiplication, division).

• Steps:

  1. Add four Button controls for each operation.

  2. Add two TextBox controls for input numbers and one Label for displaying the result.

  3. Write code in the Button click events to perform calculations and display results in the Label.

private void btnAdd_Click(object sender, EventArgs e)
{
    int num1 = int.Parse(txtNumber1.Text);
    int num2 = int.Parse(txtNumber2.Text);
    lblResult.Text = (num1 + num2).ToString();
}

2. Temperature Converter

Objective: Convert temperatures from Celsius to Fahrenheit and vice versa.

• Steps:

  1. Add a TextBox for input and a Label to display the converted temperature.

  2. Add two RadioButton controls, one for Celsius to Fahrenheit and the other for Fahrenheit to Celsius.

  3. Add a Button for the conversion.

  4. In the button's click event, check the selected RadioButton and perform the conversion.

private void btnConvert_Click(object sender, EventArgs e)
{
    double temp = double.Parse(txtTemperature.Text);
    if (rbtnCtoF.Checked)
    {
        lblResult.Text = ((temp * 9 / 5) + 32).ToString("0.##") + " °F";
    }
    else if (rbtnFtoC.Checked)
    {
        lblResult.Text = ((temp - 32) * 5 / 9).ToString("0.##") + " °C";
    }
}

3. Basic Login Form

Objective: Create a login form with username and password verification.

• Steps:

  1. Add TextBox controls for username and password, and a Button for login.

  2. Write code to verify the username and password when the button is clicked.

  3. Display a success message if the username and password are correct, or an error if they are incorrect.

private void btnLogin_Click(object sender, EventArgs e)
{
    string username = txtUsername.Text;
    string password = txtPassword.Text;

    if (username == "admin" && password == "12345")
    {
        MessageBox.Show("Login Successful!");
    }
    else
    {
        MessageBox.Show("Invalid username or password");
    }
}

4. Simple To-Do List

Objective: Allow the user to add tasks to a list, mark them as completed, and delete them.

• Steps:

  1. Add a TextBox for input and a Button to add tasks.

  2. Add a ListBox to display the tasks.

  3. Add two more buttons to mark tasks as completed and to delete selected tasks.

private void btnAddTask_Click(object sender, EventArgs e)
{
    listBoxTasks.Items.Add(txtTask.Text);
    txtTask.Clear();
}

private void btnMarkComplete_Click(object sender, EventArgs e)
{
    if (listBoxTasks.SelectedItem != null)
    {
        int index = listBoxTasks.SelectedIndex;
        listBoxTasks.Items[index] = "[Completed] " + listBoxTasks.Items[index];
    }
}

private void btnDeleteTask_Click(object sender, EventArgs e)
{
    listBoxTasks.Items.Remove(listBoxTasks.SelectedItem);
}

5. Change Background Color

Objective: Create a form where users can change the background color.

• Steps:

  1. Add several Button controls, each representing a different color.

  2. In each button's click event, change the form's BackColor.

private void btnRed_Click(object sender, EventArgs e)
{
    this.BackColor = Color.Red;
}

private void btnGreen_Click(object sender, EventArgs e)
{
    this.BackColor = Color.Green;
}