每当更新另一个文本框时更新一个文本框

Question

I have three textboxes. One for FirstName, the other for LastName, the Last for FullName.

What i want to do is that whenever the firstname textbox is filled in, the FullName should be reset to the FirstName text and the FullName textbox should be updated whenever textbox is filled.

I have tried

    private void txtFirstName_TextChanged(object sender, EventArgs e)
    {
        txtFullName.Text = txtFirstName.Text;
    }

    private void txtLastName_TextChanged(object sender, EventArgs e)
    {
        if (_New == false)
        {
            txtFullName.Text += " ";
            _New = true;
        }
        string newletter = txtLastName.Text.Substring(txtLastName.Text.Length - 1);
        txtFullName.Text += newletter;
    }

This code works to an extent but the main problems with this code is that The fullname textbox is not updated whenever a user deletes a text from the lastname textbox also, i want it that when text is deleted from the firstname textbox when there is text in the lastname textbox, The entire text shouldn't be reset but the text should be updated.

Any help will be appreciated.

Answer 1

This should work for you

    private void Form()
    {
        txtFirstName.TextChanged += TextBoxChanged;
        txtLastName.TextChanged += TextBoxChanged;
    }

    private void TextBoxChanged(object sender, EventArgs e)
    {
        txtFullName.Text = txtFirstName.Text + " " + txtLastName.Text;
    }