I hope help you.

    /// <summary>
    /// Get the integer part of any decimal number passed trough a string 
    /// </summary>
    /// <param name="decimalNumber">String passed</param>
    /// <returns>teh integer part , 0 in case of error</returns>
    private int GetIntPart(String decimalNumber)
    {
        if(!Decimal.TryParse(decimalNumber, NumberStyles.Any , new CultureInfo("en-US"), out decimal dn))
        {
            MessageBox.Show("String " + decimalNumber + " is not in corret format", "GetIntPart", MessageBoxButtons.OK, MessageBoxIcon.Error);
            return default(int);
        } 
        
        return Convert.ToInt32(Decimal.Truncate(dn));
    }

I hope help you.

/// <summary>
/// Get the integer part of any decimal number passed trough a string 
/// </summary>
/// <param name="decimalNumber">String passed</param>
/// <returns>teh integer part , 0 in case of error</returns>
private int GetIntPart(String decimalNumber)
{
    if(!Decimal.TryParse(decimalNumber, NumberStyles.Any , new CultureInfo("en-US"), out decimal dn))
    {
        MessageBox.Show("String " + decimalNumber + " is not in corret format", "GetIntPart", MessageBoxButtons.OK, MessageBoxIcon.Error);
        return default(int);
    } 
    
    return Convert.ToInt32(Decimal.Truncate(dn));
}