Decimal TextBox Class Need Modification

See more:

C#3.5

Hi.. All CodeProject Members
I download this code below from Microsoft Official Site
this Class Use For formatting textbox with numeric mask.
but i found some problem and need modified it
which it's can't accepted Minus (-) Character and i can't change the decimal digits into 4 decimal digits..
i have tried to modificated it hundred's time but still not find the
way..
Could anybody show me how the right code. then i can make the textbox
in Minus Format..and modified the decimal digits

thx for attn :
hope CodeProjects Better.. ^^

here is the code or you can download it at :
http://download.microsoft.com/download/0/8/7/087e6a47-7306-4a5c-ad97-d1ffd58d712e/DecimalTextBox.msi[^]

static NumberFormatInfo nfi = NumberFormatInfo.CurrentInfo;
/// <devdoc>
///     Overridden to validate and format the text.
/// </devdoc>
public override string Text
{
    get
    {
        return base.Text;
    }
    set
    {
        if (value != base.Text)
        {
            SetFormattedText(new StringBuilder(value));
        }
    }
}
/// <devdoc>
///     Overridden to handle unsupported RETURN key.
/// </devdoc>
protected override bool IsInputKey(Keys keyData)
{
    if ((keyData & Keys.KeyCode) == Keys.Return)
    {
        return false;
    }
    return base.IsInputKey(keyData);
}

/// <devdoc>
///     Handle input filtering and text insertion.
/// </devdoc>
protected override void OnKeyPress( KeyPressEventArgs e )
{
    base.OnKeyPress( e );

    e.Handled = true;  // This disables undersired keys. ProcessCmdKey is used to enabled supported shortcuts.
    // Filter allowed input: integers or decimal separator only.
    if( !char.IsDigit( e.KeyChar ) && e.KeyChar != nfi.NumberDecimalSeparator[0] )
    {
        return;
    }
    int caretPos = this.SelectionStart;
    StringBuilder txt = new StringBuilder( this.Text );

    if (e.KeyChar == nfi.NumberDecimalSeparator[0])
    {
        // Go to decimal input location.
        this.SelectionStart = txt.Length - nfi.NumberDecimalDigits;
        return;
    }
    if( caretPos == txt.Length ) // caret at the end of the box
    {
        // input ignored.
        return;
    }
    int originalTextLength = txt.Length;
    if( originalTextLength - caretPos <= nfi.NumberDecimalDigits ) // caret at decimal location
    {
        // Replace the current location's value with the input.
        txt[caretPos] = e.KeyChar;
        this.Text = txt.ToString();
        this.SelectionStart = caretPos + 1;
    }
    else // caret at a whole number's location or at the decimal separator's location.
    {
        // If caret is at pos 0 and the number is zero, we need to move caret so it can be inserted after the 0
        // and get properly formatted; otherwise, the input would be inserted at zero (effect = multiplied by 10).
        if( caretPos == 0 && txt[0] == '0' )
        {
            caretPos++;
        }
        // Insert value.
        txt.Insert( caretPos, e.KeyChar );
        if( SetFormattedText( txt ) )
        {
            this.SelectionStart = caretPos + ( txt.Length - originalTextLength );
        }
    }
}

/// <devdoc>
/// </devdoc>
public override void ResetText()
{
    SetFormattedText(new StringBuilder("0"));
}
/// <devdoc>
///     Sets the decimal-formatted text into the control's text.
///     Returns false if an exception is thrown during text formatting due to overflow or unexpected characters in
///     the specified text.
///     Methods calling this method should check for the return value before doing further processing.
///     The input should contain interger numbers and decimal group separator characters only; it does not expect
///     the string to represent a well formatted decimal number.
/// </devdoc>
private bool SetFormattedText( StringBuilder txt )
{
    // Remove group separators to re-format the string.
    txt.Replace( nfi.NumberGroupSeparator, "" )
    try
    {
        double value = double.Parse( txt.ToString() ); // parse decimal value.
        txt.Length = 0; // clear text.
        txt.Append( value.ToString( "N", nfi ) ); // set new text.
        base.Text = txt.ToString(); // set control's text.
        return true;

    }
    catch( System.OverflowException )
    {
        // Input too big.
    }
    catch( System.FormatException )
    {
        Debug.Fail( "Input was not in a correct format." );
        // Input not formatted properly.
    }
    return false;
}

[removed the code that has nothing to do with your problem]