Read Entity Attributes in MS CRM 2011

below is the way to read Entity Attributes and Display in GridView

// please connect to your CRM organization using appropriate URL

           IOrganizationService crmservice;
            CrmConnection crmconn = new CrmConnection();
            crmservice = crmconn.Connect2CRMNew(orguri);

            RetrieveEntityRequest retrieveEntityRequest = new RetrieveEntityRequest
            {
                EntityFilters = EntityFilters.All,
                LogicalName = entityname,
                RetrieveAsIfPublished = true
            };

            RetrieveEntityResponse retrieveEntityResponse = (RetrieveEntityResponse)crmservice.Execute(retrieveEntityRequest);
            EntityMetadata currentEntity = retrieveEntityResponse.EntityMetadata;
           
            // Attributes
           
            DataTable dtmain = new DataTable();
            dtmain.Columns.Add(new DataColumn("Schema name"));
            dtmain.Columns.Add(new DataColumn("Data Type"));
            dtmain.Columns.Add(new DataColumn("Size"));
            dtmain.Columns.Add(new DataColumn("Required Level"));
            dtmain.Columns.Add(new DataColumn("Is Audit Enabled"));
            dtmain.Columns.Add(new DataColumn("Is Custom Attribute"));
            dtmain.Columns.Add(new DataColumn("AttributeID"));
           
            foreach(AttributeMetadata allattributes in  currentEntity.Attributes)
            {
                DataRow dtrow = dtmain.NewRow();

                dtrow[0] = allattributes.LogicalName.ToString();
                dtrow[3] = allattributes.RequiredLevel.Value.ToString();
                dtrow[4] = allattributes.IsAuditEnabled.Value.ToString();
                dtrow[5] = allattributes.IsCustomAttribute.Value.ToString();
                dtrow[6] = allattributes.MetadataId.Value.ToString();
                dtrow[1] = allattributes.AttributeType.Value;

                switch (allattributes.AttributeType.Value.ToString())
                {
                    //case "Money":
                    //    dtrow[6] = ((Microsoft.Xrm.Sdk.Metadata.MoneyAttributeMetadata)(allattributes)).MaxValue.ToString();
                    //    break;
                    //case "Virtual":
                    //    dtrow[6] = ((Microsoft.Xrm.Sdk.Metadata.V)(allattributes)).MaxLength.ToString();
                    //    break;
                    case "Decimal":
                        dtrow[2] = ((Microsoft.Xrm.Sdk.Metadata.DecimalAttributeMetadata)(allattributes)).MaxValue.ToString();
                        break;
                    //case "Boolean":
                    //    //dtrow[6] = ((Microsoft.Xrm.Sdk.Metadata.BooleanAttributeMetadata)(allattributes)).
                    //    break;
                    //case "State":
                    //    //dtrow[6] = ((Microsoft.Xrm.Sdk.Metadata.StateAttributeMetadata)(allattributes)).
                    //    break;
                    case "String":
                        dtrow[2] = ((Microsoft.Xrm.Sdk.Metadata.StringAttributeMetadata)(allattributes)).MaxLength.ToString();
                        break;
                    //case "DateTime":
                    //    //dtrow[6] = ((Microsoft.Xrm.Sdk.Metadata.DateTimeAttributeMetadata)(allattributes)).
                    //    break;
                    case "Integer":
                        dtrow[2] = ((Microsoft.Xrm.Sdk.Metadata.IntegerAttributeMetadata)(allattributes)).MaxValue.ToString();
                        break;
                    //case "Lookup":
                    //    //dtrow[6] = ((Microsoft.Xrm.Sdk.Metadata.LookupAttributeMetadata)(allattributes)).
                    //    break;
                    //case "Uniqueidentifier":
                    //    //dtrow[6] = ((Microsoft.Xrm.Sdk.Metadata.Uniq)(allattributes)).
                    //    break;
                    //case "Picklist":
                    //    //dtrow[6] = ((Microsoft.Xrm.Sdk.Metadata.PicklistAttributeMetadata)(allattributes)).OptionSet.
                    //    break;



                };
                dtmain.Rows.Add(dtrow);
            }
            gvAttributes.DataSource = dtmain.DefaultView;
            gvAttributes.DataBind();
            pnlattribute.Visible = true;
            Session.Add("TaskTable",dtmain);