Category: ASP.NET Page 3 of 5

In ASP.NET

Auto-attach to process ‘[2440] w3wp.exe’ on machine ‘…’ failed. Error code 0x8013134b. This problem is most likely occurred because I have two .NET framework installed in my PC (v1.14322 and v2.0).

To fix this problem:

• Open IIS (inetmgr)
• Right click on the web site with the problem
• Click the ASP.NET tab
• Change the ASP.NET version from 2.something to 1.14322 in the dropdown(or vice versa) and debugging works again

Enums with description in c#

In .NET & C#, ASP.NET, C#, VB.NET

Sometime when we have Enum , we want to use it /bind it on the list as well with a better description/ word. With this method you can bind enum to a list which display its description but store its value as well.This is very useful function.

using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;
using System.Reflection;
using System.ComponentModel;

public class Enums
    {
        #region helpers
        public static string GetEnumDescription(Enum value)
        {
            FieldInfo fi = value.GetType().GetField(value.ToString());
            DescriptionAttribute[] attributes =
              (DescriptionAttribute[])fi.GetCustomAttributes
              (typeof(DescriptionAttribute), false);
            return (attributes.Length > 0) ? attributes[0].Description : value.ToString();
        }

        public static T Parse(string input)
        {
            return (T)Enum.Parse(typeof(T), input);
        }
        #endregion

        #region enums
        public enum ResultsType
        {
            [Description("Featured Products")]
            FeaturedProducts,
            [Description("New Products")]
            NewStock,
            CategoryResults,
            [Description("Specials")]
            Specials,
            Brand,
            Row1,
            Row2,
            Row3,
            [Description("This Weeks Specials")]
            ThisWeeksSpecials,
            [Description("Top 10 Best Sellers")]
            Top10BestSellers,
            [Description("Special Offers")]
            SpecialOffers,
            [Description("Buy 1 Get 1 Free")]
            Buy1Get1Free,
            [Description("Half Price Bargains")]
            HalfPriceBargains,
            [Description("Top Sellers")]
            TopSellers,
            [Description("Summer Specials")]
            SummerSpecials,
            [Description("CUSTOMERS WHO BOUGHT THIS ALSO BOUGHT")]
            AlsoBought,
            [Description("Related Products")]
            Upsell
        }

          public enum ReportType
         {
            [Description("Monthly Sales Report")]
            MonthySalesReport = 1,
            [Description("Dispatched Orders Report")]
            DispatchedOrdersReport = 2,
            [Description("Order Report")]
            OrderReport = 3
         }

#endregion

}

This is how you bind it

Private Sub PopulateReportType()

        ddlReportType.Items.Clear()
        ddlReportType.Items.Add(New ListItem(Enums.GetEnumDescription(Enums.ReportType.MonthySalesReport), Convert.ToInt32(Enums.ReportType.MonthySalesReport)))
        ddlReportType.Items.Add(New ListItem(Enums.GetEnumDescription(Enums.ReportType.DispatchedOrdersReport), Convert.ToInt32(Enums.ReportType.DispatchedOrdersReport)))
        ddlReportType.Items.Add(New ListItem(Enums.GetEnumDescription(Enums.ReportType.OrderReport), Convert.ToInt32(Enums.ReportType.OrderReport)))

    End Sub

Raise Event in User Control

In .NET & C#, ASP.NET, VB.NET

I need to create a payment gateway user control that will be used accross all of the modules. This user control should be as simple as doing the transaction ONLY. So what I need to do is to let the host/page container knows whether the transaction is succeeded or not, if it is succeeded then the rest of the logic will be handled on ASPX page.

In order to do so I need to create an event on the user control that will be bubbled up to the page container/host. This sample might not be the best solution but it works perfectly for my needs and only requires several lines of code.

Write this in your user control including declaration(signature) of parameter that you want to pass

Partial Class usercontrols_MyPaymentGateway
    Inherits System.Web.UI.UserControl

#Region "Property"

    ''' 
    ''' this is an event for process status
    ''' 
    ''' 
    Public Event getProcessStatus(ByVal isPaid As Boolean)

Write this in your user control where you want to raise the event and pass the parameter

     RaiseEvent getProcessStatus(True)

Write this in your page container(Create an Event handler to handle your user control events) (NOTE: paymentGateway is the name of your user control)

 ''' 
    ''' event handler to the payment gateway controls
    ''' 
    ''' 
    ''' 
    Private Sub paymentProcessed(ByVal isPaid as boolean) Handles paymentGateway.getProcessStatus

        If (paymentGateway.IsPaid) Then
            ltMessage.Text = "Payment Successful " + paymentGateway.ResponseMessage

            'if it is paid then we need to clear the remaining text boxes
            paymentGateway.ClearFields()
        Else
            ltMessage.Text = "Payment Failed " + paymentGateway.ResponseMessage
        End If

    End Sub

Reference to user control in web.config

In ASP.NET, VB.NET

I’ve seen that most of people put their user control declaration in individual aspx page, and they declare it on the top of that page. What will happen if you are going to use it on multiple number of pages and i believe most of you would like to have a kind of tag that you can simply use on your web page to add your user control. In here, we declare all the user controls in web.config which I believe is more clean and manageable.

Web.Config

How to use it in ASPX Page






    Untitled Page

Find a control in ContentPlaceHolder

In ASP.NET, VB.NET

I have a user control and I would like to hide a control on the page container that host this user control. I try to use

Page.FindControl("litContent")

But It throws an error of object not found. The solution is you need to find the contentplaceholder first on the master page then you find the control that you want from that placeholder. It’s a bit tricky since i thought once you get a Page instance then you can get all control hosted on the Page instance itself.

1. Place this tag on your asp.net page where it hosts your control

2. go to the page behind of the user control/page where you want to place your logic to hide/show it

'hide the dynamic page from the parent page
Dim mainContent As ContentPlaceHolder = CType(Page.Master.FindControl("ContentPlaceHolder1"), ContentPlaceHolder)

If Not (mainContent Is Nothing) Then
   Dim contentPlaceHolder As Literal = CType(mainContent.FindControl("litContent"),Literal)
   If Not (contentPlaceHolder Is Nothing) Then
       contentPlaceHolder.Visible = False
   End If
End If

AJAX Update Panel Timeout Issue

In ASP.NET, JavaScript

I have an asp.net page where the page will query the report from the database. To query the report itself might cause timeout exception on the page itself before the report result is being returned from database.

You need to do it in two steps, first you need to override the script timeout only for the pageitself. put this code in your code behind

    Dim pageTimeOut As Integer
Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
        pageTimeOut = Server.ScriptTimeout

        'this is in seconds
        Server.ScriptTimeout = 2500
End Sub

Protected Sub Page_Unload(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Unload

Server.ScriptTimeout = pageTimeOut

End Sub

The next step is required only if you use AJAX Update panel. Put this script on the aspx page


   Sys.WebForms.PageRequestManager.getInstance().add_endRequest(
        function (sender, args)
        {
             if (args.get_error() && args.get_error().name == 'Sys.WebForms.PageRequestManagerTimeoutException')
            {
                  // remember to set errorHandled = true to keep from getting a popup from the AJAX library itself
                 args.set_errorHandled(true);
             }
        });

File Stream/Stream response in AJAX Update Panel

In ASP.NET, C#

Last few months, I got a problem to place a button to generate a CSV file in the update panel. I was having a problem related with response error. So what i did was to place the button outside the Update Panel. Today, I found a simple solution to place this button inside the AJAX Update panel

1. You need to set the page mode on the page load event

protected void Page_Load(object sender, EventArgs e)
{
    this.Page.Form.Enctype = "multipart/form-data";
}

2. set the update Panel Children as trigger to true

3. set the trigger to your button

Filtering Field/Column in DataTable

In ASP.NET, C#, VB.NET

I was having a problem when I have the same datatable and one datagrid but I want to display different field on the grid for different report and I want to use AutoGenerateColumn = true in the datagrid. Remember, it is about filtering fields not Row(If you want to filter row then you can use dataview).

This is the way of filtering field in datatable

     public static DataTable FilterTableRemoveColumns(tdsReports.ReportSelectDataTable inputTable, List fields)
        {
            //create a new data table
            DataTable newTable = new DataTable();
            newTable.TableName = "newtable";

            //iterate through each column
            foreach (DataColumn col in inputTable.Columns)
            {
                //cross match and filter fields/column
                if (fields.Contains(col.ColumnName))
                {
                    //create a new datacolumn with the same column name and same datatype
                    DataColumn newCol = new DataColumn(col.ColumnName, col.DataType);
                    newTable.Columns.Add(newCol);
                }
            }

            //you ignore the schema because you don't want to throw the exception
            //you merge the data with the new schema
            newTable.Merge(inputTable, true, MissingSchemaAction.Ignore);
            return newTable;
        }

this is how you use it. You pass a string list into the function. The string list contains your desired column

Private Function FilterDataTableColumn(ByVal dtReport As tdsReports.ReportSelectDataTable) As DataTable

        Dim dt As DataTable = New DataTable()
        Try
            Dim list As List(Of String) = New List(Of String)

            If (ReportType = Enums.ReportType.DispatchedOrdersReport) Then
                list.Add("OrderID")
                list.Add("PaymentType")
                list.Add("ProductCode")
                list.Add("Qty")
                list.Add("Price")
                list.Add("Total")
                list.Add("IncGst")

            ElseIf (ReportType = Enums.ReportType.MonthySalesReport) Then
                list.Add("Qty")
                list.Add("ProductCode")
                list.Add("ProductName")

            ElseIf (ReportType = Enums.ReportType.OrderReport) Then
                list.Add("ProductCode")
                list.Add("Qty")
                list.Add("ProductName")

            End If

            dt = objReportService.FilterTableRemoveColumns(dtReport, list)

        Catch ex As Exception

        End Try

        Return dt
    End Function

Set Default value with clear text for input type=”password”