FlexiCoder Blog » C# 3.5

XSL/T Transform from String to String

flexicoder — Wed, 22 Jul 2009 09:01:19 +0000

The following example transforms the supplied xml string, using XSL/T and outputs to another string


using (StringReader rdr = new StringReader(selectedLine.AdditionalInformation))
{
    XPathDocument doc = new XPathDocument(rdr);

    using (StringWriter writer = new StringWriter())
    {

        transformer.Transform(doc, null, writer);
        titleLabel.Attributes.Add("onmouseover", string.Format(@"showDiv(""{0}"")", writer.ToString()));
    }
}

The XSL/T loaded into the transformer variable is as follows

And a sample xml string is as follows:

The result from the transformation is as follows:



Body Rides


Additional answer code


Additional answer date


Answer code


TOS


Answer date


Author
Richard Laymon


Delivery to
Company Name, Address Line 1, AddressLine 2


Expected delivery
09/08/2009


Held orders


Ordered on
20/07/2009


Print runs

The code to build up the xml within the object is below, note that the values are HtmlEncoded to ensure that there are no problems in the web page.

public string AdditionalInformation
{
    get
    {
        StringBuilder builder = new StringBuilder();
        builder.Append(string.Format(CultureInfo.CurrentCulture,
                                        @"",
                                        HttpUtility.HtmlEncode(this.Title)));
        AddLabelValue(builder, "Account number", ParentPurchaseOrder.AccountNumber);
        AddLabelValue(builder, "Additional answer code", this.AdditionalAnswerCode);
        AddLabelValue(builder, "Additional answer date",
            this.AdditionalAnswerDate.Year != 1 ? this.AdditionalAnswerDate.ToShortDateString() : "" );
        AddLabelValue(builder, "Answer code", this.AnswerCode);
        AddLabelValue(builder, "Answer date",
            this.AnswerDate.Year != 1 ? this.AnswerDate.ToShortDateString() : "");
        AddLabelValue(builder,"Author", this.Author);
        AddLabelValue(builder, "Delivery to",
            ParentPurchaseOrder.DeliveryName + ", " + ParentPurchaseOrder.Address1 + ", " +
                          ParentPurchaseOrder.Address2 + ", " +
                          ParentPurchaseOrder.Address3 + ", " +
                          ParentPurchaseOrder.Address4 + ", " +
                          ParentPurchaseOrder.Address5 + ", " +
                          ParentPurchaseOrder.Postcode);

        AddLabelValue(builder, "Expected delivery",
ParentPurchaseOrder.ExpectedDeliveryDate.ToShortDateString());
        AddLabelValue(builder, "Held orders", this.HeldOrders);
        AddLabelValue(builder, "Ordered on", ParentPurchaseOrder.OrderedOn.ToShortDateString());
        AddLabelValue(builder, "Print runs", this.PrintRuns);
                builder.Append("");

        return builder.ToString();

    }
}

private void AddLabelValue(StringBuilder builder, string label, string value)
{
      builder.Append(string.Format(CultureInfo.CurrentCulture,
                        @"",
                         label, HttpUtility.HtmlEncode(value)));
}

?? Operator (C# Reference)

flexicoder — Fri, 22 May 2009 10:30:00 +0000

This operator allows you to supply an alternative value if the value being supplied is null. It only works on nullable datatypes but with a bit of googling came accross this article.

public int CurrentPage
{
    get
    {
        return (int)(ViewState["_CurrentPage"] ?? 0);
    }
    set
    {
        this.ViewState["_CurrentPage"] = value;
    }
}

The offical Microsoft article

Creating Event Handler Signatures

flexicoder — Tue, 21 Apr 2009 10:43:00 +0000

In Visual Studio 2008 you’ve lost the abillity to click on the drop down in the code behind and see all the event signatures that are available but haven’t handled yet. To get the signature you are after without using the properites in the desinger you can type…

this.

As you hit the . all methods and events should appear, pick the event you after e.g. Load

Then add type += after the event name and press TAB TAB, the event is automatically generated. ASP.Net auto wires the events with the correct name and signature so you should be able to delete the line of code that binds the event.

Check out this article for more info.

SessionId – keeping it the same

flexicoder — Mon, 23 Feb 2009 10:31:00 +0000

If you don’t populate a value in the session of a page then the session Id will reset everytime the page is loaded.


protected void Page_PreInit(object sender, EventArgs e)
{
    //Need this line otherwise it resets the Session Id everytime!
    Session["keepme"] = "True";
}

Sort Collection

flexicoder — Mon, 09 Feb 2009 14:16:00 +0000

Here is a simple solution based on this article to implement a sort of a generic collection.


public ContentCollection Sort()
{
    List items = (List)Items;
    items.Sort();
    return this;
}

The Content class needs to implement IComparable

C# – IsNumeric

flexicoder — Thu, 22 Jan 2009 09:35:00 +0000

Use the TryParse method to determine if a value is numeric

int retNum;
if (Int32.TryParse(BookId, System.Globalization.NumberStyles.Any, System.Globalization.NumberFormatInfo.InvariantInfo, out retNum))
{
    //Is numeric
}

Singleton Class – Basic Example

flexicoder — Tue, 13 Jan 2009 16:14:00 +0000

Below is an example of a Singleton implementation C# class.

public sealed class StaticData
{
    private  StaticData() {}
    public static readonly StaticData Instance = new StaticData();
    string connectionString = "";
    public string ConnectionToUse
    {
        get
        {
            if (connectionString.Length == 0)
            {
                connectionString = System.Configuration.ConfigurationManager.AppSettings.Get("DBConnection").ToString();
            }
            return connectionString;
        }
    }
}

Output Parameters with returned value

flexicoder — Thu, 08 Jan 2009 10:06:00 +0000

When using output parameter values you need to check that the value is not DBNull before using it…

using (SqlConnection conn = new SqlConnection())
{
    conn.ConnectionString = System.Configuration.ConfigurationManager.AppSettings.Get("DBConnection").ToString();
    conn.Open();
    using (SqlCommand cmd = new SqlCommand())
    {
        cmd.Connection = conn;
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Parameters.Add(new SqlParameter("@ChapterId", _ChapterId));
        cmd.Parameters.Add(new SqlParameter("@Sequence", _Sequence));
        cmd.CommandText = "Get_ContentPrevNext";
        SqlParameter parameterPreviousId = new SqlParameter("@PreviousId", System.Data.SqlDbType.Int)
        {
            Direction = System.Data.ParameterDirection.Output
        };
        cmd.Parameters.Add(parameterPreviousId);
        SqlParameter parameterNextId = new SqlParameter("@NextId", System.Data.SqlDbType.Int)
        {
            Direction = System.Data.ParameterDirection.Output
        };
        cmd.Parameters.Add(parameterNextId);
        cmd.ExecuteNonQuery();
        if (parameterPreviousId.Value != DBNull.Value)
        {
            _PreviousId = Convert.ToInt32(parameterPreviousId.Value);
        }
        if (parameterNextId.Value != DBNull.Value)
        {
            _NextId = Convert.ToInt32(parameterNextId.Value);
        }
    }
}

Image from Byte Array

flexicoder — Wed, 07 Jan 2009 16:17:00 +0000

To render an image to a picturebox using the data stored in a byte array use the following code


using (MemoryStream ms = new MemoryStream(ImageDetails.ThumbnailImage))
{
    ThumbnailImage.Image = Image.FromStream(ms);
}

Render Image using Generic Handler ASP.Net

flexicoder — Wed, 07 Jan 2009 11:27:00 +0000

The following code uses a property from an object that returns a byte array that contains an image.

public void ProcessRequest(HttpContext context)
{
    context.Response.ContentType = "image/jpg";
    if (context.Request.Params["Id"] != null)
    {
        Content selectedImage = new Content(Convert.ToInt32(context.Request.Params["Id"].ToString()));
        if (context.Request.Params["t"] == "D")
        {
            context.Response.OutputStream.Write(selectedImage.ImageDetails.FullImage, 0, selectedImage.ImageDetails.FullImage.Length);
        }
        else
        {
            context.Response.OutputStream.Write(selectedImage.ImageDetails.ThumbnailImage, 0, selectedImage.ImageDetails.ThumbnailImage.Length);
        }
    }
}

Body Rides
Additional answer code
Additional answer date
Answer code
TOS
Answer date
Author	Richard Laymon
Delivery to	Company Name, Address Line 1, AddressLine 2
Expected delivery	09/08/2009
Held orders
Ordered on	20/07/2009
Print runs