private void sDoubleBox_KeyPress(object sender, KeyPressEventArgs e)
{
    if (e.KeyChar == ' ') //禁止空格键
    {
        e.Handled = true;
        return;
    }
    if (((TextBox)sender).Text.Equals(((TextBox)sender).SelectedText)) //處理全選
    {
        ((TextBox)sender).Text = null;
    }
    if ((e.KeyChar == '-') && (((TextBox)sender).SelectionStart == 0)) return;   //處理負號
 
    if (e.KeyChar > ' ')
    {
        try
        {
            double.Parse(((TextBox)sender).Text + e.KeyChar.ToString());
        }
        catch
        {
            e.Handled = true;
        }
    }
}

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