Question

I need to validate a textbox as follows:

When the user changes focus from that textbox, I want to show the properly formated currency value, but without lost the real user-entered value, Because i need it for later Calculations, and if is the case, for later editing from the user…

Can i do that? i don’t want to have another variable just for that, and i remmeber the “validating” (i think) event on datagrid view that lets you keep the value and format that value, so if you have to change or use for calculations, you just use the VALUE property, and for showing, it uses the FORMATEDVALUE property…
Can i do that?

Thanks!

Answer 1

Define a function which formats the user entered value and returns the formatted value. On the LostFocus event of the text box you can accept the value entered by the user and store it into a variable. Then, pass the variable value as a parameter to the function. Format your value and return the value to the textbox.

    private void textBox1_Leave(object sender, EventArgs e)
    {
        Int32 original_value = Convert.ToInt32(textBox1.Text);
        textBox1.Text = Format(original_value).ToString();
        //original_value still holds the value that the user entered.
        //textbox holds the formated value.

    }
    public int Format(int a)
    {
        //code to format your input value
        return a;
    }

This way your variable holds the acutal value entered by the user and the textbox will display the formatted value. Does this help.

If you do not want to use another variable at all then you can perhaps make your own class control that inherits the textbox control, or just get the source, and use the Override attribute for the class.
this might help.