Question

I need to generate windows form fields based off of a text file that I am parsing. I also want to automatically generate validation event handlers which all will be basically the same only the form field and the regular expression which is used to validate the field will change.

I’m having a difficult time figuring out the quickest and easiest method to go about doing this.

Any pointers in the right direction would really be great, maybe even some keywords that I’m missing. I can only imagine this type of question has been covered before, I just don’t know what I’m searching for really.

Answer 1

I have done something similar using XML to generate controls at runtime

The easiest way i found was to create custom controls to allow easy validation.

I also collect details regarding the controls to be able to return the value of the fields to the webservice

Here is how i achive this

  public bool IsFieldValid()
    {
             Error.SetError(label, "");
        if (_Validate.Length == 0)
        {
         return true;
        }

        else 
        {
            switch (_Validate)
            { 
                case "General":
                    return ValidateText();
                case "Int":
                    return ValidateInt();
                case "Decimal":
                    return ValidateDecimal();
                case "Length":
                    return ValidateTextLength();
                default:
                    return true;
            }


        }


    }


    public bool ValidateText()
    {

            this.shapeContainer1.BackColor = this.BackColor;
            if (_CanBeNull == true & this.textBox.Text.Trim() == "")
            {

                return true;
            }
            else
            {
                if (this.textBox.Text.Trim().Length > 0)
                {

                    return true;
                }
                else
                { 
                    Error.SetError(label, CustomError);
                    return false;
                }

        }
    }

    public bool ValidateDecimal()
    {

        if (_CanBeNull == true & this.textBox.Text.Trim() == "")
        {
            return true;
        }
        else
        {
            try
            {
                this.textBox.Text = this.textBox.Text.Replace("£", "");
                Decimal Val = System.Convert.ToDecimal(this.textBox.Text);
                if (_MaxValue == 0)
                {
                    return true;
                }

                if ((Val >= _MinValue) && (Val <= _MaxValue))
                {
                    return true;
                }
                else
                {

                    this.Error.SetError(this.label, "Value must be between " + _MinValue.ToString() + " and " + _MaxValue);
                    return false;

                }


            }
            catch
            {
                this.Error.SetError(this.label, "Error converting value to a decimal value");
                return false;
            }



        }

    }

    public bool ValidateInt()
    {
        if (_CanBeNull == true & this.textBox.Text.Trim() == "")
        {
            return true;
        }
        else
        {
            try
            {
                int Val = System.Convert.ToInt32(this.textBox.Text);
                if (_MaxValue == 0)
                {
                    return true;
                }

                if ((Val >= _MinValue) && (Val <= _MaxValue))
                {

                    return true;
                }
                else
                {

                    this.Error.SetError(label,"Value must be between " + _MinValue.ToString() + " and " + _MaxValue);
                    return false;

                }


            }
            catch
            {
                this.Error.SetError(label,"Error converting value to a numeric value");
                return false;
            }



        }
    }

    public bool ValidateTextLength()
    {
        if (_CanBeNull == true & this.textBox.Text.Trim() == "")
        {
            return true;
        }
        else
        {

            int Val = this.textBox.Text.Length;
            if ((Val >= _MinValue) && (Val <= _MaxValue))
            {
                return true;
            }
            else
            {

                this.Error.SetError(label,"Length of text must be between " + _MinValue.ToString() + " and " + _MaxValue);
                return false;

            }





        }
    }


    public String TxtReturnXML
    { 
        get {
            string S;
            XmlDocument doc = new XmlDocument();
            XmlNode Xe = doc.CreateNode(XmlNodeType.Element,"Value",null);
            Xe.InnerText = this.textBox.Text.ToString();
            S = Xe.OuterXml;
            doc = null;
            Xe = null;
            return S;


        }



    }

    public bool LoadedXml(XmlNode X)
    {
        try
        {
            _Validate = X.Attributes["Validate"].Value;

            this.textBox.Text = X.Attributes["DefaultValue"].Value.ToString();
            this.label.Text = X.Attributes["LabelText"].Value.ToString();

            if (System.Convert.ToInt32(X.Attributes["Height"].Value) > 0)
            {
                this.Height = System.Convert.ToInt32(X.Attributes["Height"].Value) + 10;
                textBox.Multiline = true;
                this.textBox.Height = System.Convert.ToInt32(X.Attributes["Height"].Value);
            }
            if (System.Convert.ToInt32(X.Attributes["Width"].Value) > 0)
            {
                this.textBox.Width = System.Convert.ToInt32(X.Attributes["Width"].Value);
                this.textBox.Left = (this.Width - 20) - System.Convert.ToInt32(X.Attributes["Width"].Value);
            }
            _CanBeNull = System.Convert.ToBoolean(X.Attributes["CanBeNull"].Value);
            _PassBack = System.Convert.ToBoolean(X.Attributes["PassBack"].Value);

            CustomError = X.Attributes["CustomError"].Value.ToString();
            CustomWarning = X.Attributes["CustomWarning"].Value.ToString();
            if (CustomWarning.Length > 0)
            {
                Error.SetError(label, CustomWarning);

            }


            _MinValue = System.Convert.ToInt32(X.Attributes["MinValue"].Value);
            _MaxValue = System.Convert.ToInt32(X.Attributes["MaxValue"].Value);



        }
        catch {
            return false;
        }

            _LoadedXml = X;
            return true;



}

You could also add event handles to validate at a specific event(i.e blur)

Hope this helps

Sp