Cast ArrayList used in Gridview datasource to Datatable without loops

Question

Dear All I would like to Cast Arraylist into datatable Arraylist can be bound in Gridview and displayed in table format why Gridview.Datasource is not convertable to Datatable ? is there any easier way to convert collections into Datatable i have thousands of records ..using loops wil not be good Advanced thanks

Vulpes · Answer

Thanks Jagan :) Just a point on naming when using this technique. The DataColumns will be given the names of the class properties - Type Answer Question Id here - and so you can use retrieve columns by these names as well as by their index. However for an ArrayList the DataSet will be given the name ArrayOfAnyType and the (only) DataTable will be given the name anyType bearing in mind that an ArrayList stores its elements internally in an object array. If you don't like these names then you can change them by setting the ds.DataSetName and/or dt.TableName properties.

Jaganathan Bantheswaran · Answer

Really great Vulpes....

Vulpes · Answer

You can use XML serialization to convert an ArrayList to a DataTable as the following console app shows: using System; using System.Collections; using System.Xml.Serialization; using System.Data; using System.IO; public class QuestionAnswer // needs to be public { public string Type {get; set;} public string Answer {get; set;} public string Question {get; set;} public int Id {get; set;} public QuestionAnswer(string type string answer string question int id) { Type = type; Answer = answer; Question = question; Id = id; } public QuestionAnswer() {} // class must also have a parameterless constructor } class Test { static void Main() { ArrayList al = new ArrayList(); al.Add(new QuestionAnswer(SampleProject.QuestionAnswer a b 1)); al.Add(new QuestionAnswer(SampleProject.QuestionAnswer b c 2)); XmlSerializer xs = new XmlSerializer(typeof(ArrayList) new Type[]{typeof(QuestionAnswer)}); MemoryStream ms = new MemoryStream(); xs.Serialize(ms al); ms.Position = 0; DataSet ds = new DataSet(); ds.ReadXml(ms); ms.Close(); DataTable dt = ds.Tables[0]; foreach(DataRow dr in dt.Rows) { Console.WriteLine({0} {1} {2} {3} dr[0] dr[1] dr[2] dr[3]); } Console.ReadKey(); } }

narasimman g · Answer

Unable to cast object of type 'ArrayList' to type System.Data.Datatable

Jaganathan Bantheswaran · Answer

Hi What is the error statement ?

narasimman g · Answer

Hi Jagan Thanks for the Response Problem is I am using ArrayList as Datasource :( Am not able to cast but if i bind in gridview it works like a charm The ArrayList Looks like al[0] SampleProject.QuestionAnswer Answer : a Question : b Id : 1 a[1] SampleProject.QuestionAnswer Answer : b Question : c id : 2

Jaganathan Bantheswaran · Answer

Hi You can do like this... First Ex. DataTable dt = (DataTable)GridViewArgs.DataSource; Second Ex. DataView dataview = ((DataTable)GridViewArgs.DataSource).DefaultView; DataTable dt = dataview.Table.Clone();