How would I use and implement a MaskedTextBox into my Calculator application? C#

Question

So I'm working on a calculator application in C-Sharp and I want to prevent people from entering more than 1 period/point at once. So they can't type "....." or "1..1" or "1.1.1" Really just stuff like that.... I would also like to prevent them from adding alphabetical characters in by typing them in with the keyboard, characters like "a, b, c".

I was told to use a MaskedTextBox, and I want to know if that is correct. Also, if it is correct, how would I implement it into my code? I'm a complete beginner when it comes to C#, so I would like some help (toned down for a beginner).

So far the code I have written is:

    double total1 = 0;
    double total2 = 0;

    public Form1()
    {
        InitializeComponent();
    }

    private void btnOne_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnOne.Text;
    }

    private void btnTwo_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnTwo.Text;
    }

    private void btnThree_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnThree.Text;
    }

    private void btnFour_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnFour.Text;
    }

    private void btnFive_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnFive.Text;
    }

    private void btnSix_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnSix.Text;
    }

    private void btnSeven_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnSeven.Text;
    }

    private void btnEight_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnEight.Text;
    }

    private void btnNine_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnNine.Text;
    }

    private void btnZero_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnZero.Text;
    }

    private void btnClear_Click(object sender, EventArgs e)
    {
        txtDisplay.Clear();
    }

    private void btnPlus_Click(object sender, EventArgs e)
    {
        total1 = total1 + double.Parse(txtDisplay.Text);
        txtDisplay.Clear();
    }

    private void btnEquals_Click(object sender, EventArgs e)
    {
        total2 = total1 + double.Parse(txtDisplay.Text);
        txtDisplay.Text = total2.ToString();
        total1 = 0;

    }

    private void btnPoint_Click(object sender, EventArgs e)
    {
        txtDisplay.Text = txtDisplay.Text + btnPoint.Text;
    }

    private void label1_Click(object sender, EventArgs e)
    {

    }

    private void txtDisplay_TextChanged(object sender, EventArgs e)
    {

    }
}

So I ask... how/where do I add in this "MaskedTextBox" - if that is correct? How do I implement it? What makes it work?

Thanks!

Answer 1

You can also save a big amount of code if you write the code of the click event just once and asign the click event handlers of every number buttons to it:

    private void btnNumber_Click(object sender, EventArgs e)
    {
        if (sender is Button)
            txtDisplay.Text = txtDisplay.Text + ((Button)sender).Text;
    }

So you can save all of the following methods

private void btnZero_Click(object sender, EventArgs e) (...)
private void btnOne_Click(object sender, EventArgs e) (...)
.
.
.
private void btnNine_Click(object sender, EventArgs e) (...)

Answer 2

In addition to MusiGenesis's snippet, you can use the KeyPress event of the text box to prevent non-digits and multiple periods.

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    if(char.IsDigit(e.KeyChar) || ((e.KeyChar == '.' && textBox1.Text.IndexOf(".") < 0) ) )
    {
        textBox1.Text += e.KeyChar;
    }
    e.Handled = true;
}

or set ReadOnly property of the text box to true.

Answer 3

You don't need a MaskedTextBox, since you're simulating the keypad with your buttons. Just put something like this in btnPoint_Click:

private void btnPoint_Click(object sender, EventArgs e)     
{         
    if (!txtDisplay.Text.Contains("."))
    {
        txtDisplay.Text = txtDisplay.Text + btnPoint.Text;    
    } 
}