In Xamarin Forms there is a native function called UriBuilder: it allow you to create a well-formed url. In my implementation, all parameters are in a Dictionary called parameters. Using Linq, I put in builder.Query only the parameters with a value. UriBuilder builder = new UriBuilder(yourUrl); Dictionary<string, string> parameters = new Dictionary<string, string>(); parameters.Add(“reference”, Reference); parameters.Add(“param1”, Param1); builder.Query = string.Join(“&”, parameters.Where(p => !string.IsNullOrWhiteSpace(p.Value)) .Select(p => string.Format(“{0}={1}”, Uri.EscapeDataString(p.Key), Uri.EscapeDataString(p.Value)))); return builder.ToString(); Happy coding!
Search Results for: linq
Binding FormattedString for Xamarin Forms
Xamarin Forms doesn’t have a Label with a Bindable FormattedString. For example, if you want a bindable bold word in the middle of a sentence in a Label, it’s very hard to design it with common control. For that, I create my own component for that. LabelRenderer.cs using System.Collections.Generic; using System.Collections.ObjectModel; using System.Collections.Specialized; using System.Linq; using System.Runtime.CompilerServices; using Xamarin.Forms; namespace PSC.Controls { public class Label : Xamarin.Forms.Label { protected override void OnBindingContextChanged() { base.OnBindingContextChanged(); UpdateFormattedTextBindingContext(); } protected override void OnPropertyChanged( [CallerMemberName] string propertyName = null) { base.OnPropertyChanged(propertyName); if (propertyName ==…
Xamarin: how to Start an Application at Device Bootup in Android
This tutorial will explain to stat an application while the Android device boot-up. For this, we need to listen to the BOOT_COMPLETED action and react to it. BOOT_COMPLETED is a Broadcast Action that is broadcast once, after the system has finished booting. You can listen to this action by creating a BroadcastReceiver that then starts your launch Activity when it receives an intent with the BOOT_COMPLETED action. Add this permission to your manifest In your Android.Manifest you must add thi permission: <uses-permission android:name=”android.permission.RECEIVE_BOOT_COMPLETED” /> Then open this file and…
Render in MVC a link with image and text
Hi guys, I want in MVC to render a text with an image as an ActionLink. For creating a simple anchor tag, we use Html.ActionLink() helper which generates anchor tag for us. If you want to create something a bit more complicated, you must create you own component. For this reason, I created the following code. It allows you to create an anchor with an image and a text. using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using System.Web.Routing; namespace PSC.MVC.Helpers { public static class CustomHtmlHelpers { ///…
“System.IO.FileNotFoundException” using controls from another assembly in Xamarin Forms on iOS.
I was building a Xamarin solution with my components like that: All my components (PSC.Xamarin.Controls.*) are working fine in other solutions.Always fine for Windows or UWP solutions. A problem was born when I started to deployed my solutions on iOS. When on the app I opened a page with my controls I always received an error like: System.IO.FileNotFoundException: Could not load file or assembly ‘PSC.Xamarin.Controls.BindablePicker’ or one of its dependencies. The system cannot find the file specified. I can check my references and deployment settings in all ways, it turns…
Remove multiple line in the same file with C#
Read the file, remove the multiple line (but it saves one of them) in memory and put the contents back to the file (overwriting) and create a backup file with the original file. using System; using System.Collections.Generic; using System.IO; using System.Linq; namespace DelMultiLine { class Program { static void Main(string[] args) { if (args.Count() == 0 || args.Count() > 2) { Console.WriteLine(“\nDelMultiLine (by Enrico Rossini – puresourcecode.com)”); Console.WriteLine(“———————————————————————–“); Console.WriteLine(“Remove duplicate line in a file\n”); Console.WriteLine(“Usage:”); Console.WriteLine(” delmultiline <Filename> <resultFilename>\n”); Console.WriteLine(“filename: define a full path for the file you want…
Dijkstra’s Algorithm in C# with Generics
I recently needed to to implement a shortest-path algorithm (to identify preferred domain controllers using site link costs) and I found Dijkstra’s Algorithm Path class using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace DijkstraAlgorithm { public class Path<T> { public T Source { get; set; } public T Destination { get; set; } /// <summary> /// Cost of using this path from Source to Destination /// </summary> /// /// Lower costs are preferable to higher costs /// </remarks> public int Cost { get; set; } } }…
Data and data access technologies
In my previous post I spoke about key layers of distributed applications. Now we will go through the most crucial layer of any distributed application, the data layer. In this part, you will be introduced to various database technologies, along with .NET-related technologies. Data can be stored in a wide range of data sources such as relational databases, files on the local filesystems, on the distributed filesystems, in a caching system, in storage located on the cloud, and in memory. Relational databases (SQL server): This is the traditional data source…
C# and HTML5: drag and Drop elements
HTML5 API includes Drag and Drop (DnD) native functionality. The event listener methods for all the drag and drop events accept Event object which has a readonly attribute called dataTransfer. The event.dataTransfer returns DataTransfer object associated with the event This is the list of events fired during the different stages: Event Description dragstart Fires when the user starts dragging of the object. dragenter Fired when the mouse is first moved over the target element while a drag is occuring. A listener for this event should indicate whether a drop is…
Integration with C# and ReactJS
The goal for this project is to show a list of books with ReactJS from a WebAPI written in C#. You can download this project from Github. New project Start by creating a new ASP.NET MVC 4 project: 1. File → New → Project 2. Select ".NET Framework 4" and Templates → Visual C# → Web → ASP.NET MVC 4 Web Application. Call it "CSReact" 3. In the "New ASP.NET MVC 5 (or 4) Project" dialog, select the MVC (or empty) template. Install ReactJS.NET We need to install ReactJS.NET to…
Customize Json result in Web API
If you work with Visual Studio 2015 and WebAPI, this short post is for you! We have to make our Web API project easy to debug so, I’m going to remove the XML formatter. I’m doing that because I’m in a test project and I’d like to see the response in the browser. The easily way to force the response to Json for all Web API requests is to remove the XML. Obviously you shouldn’t do it in production. Global.asax var formatters = GlobalConfiguration.Configuration.Formatters; formatters.Remove(formatters.XmlFormatter); Now we can start change…
Creating a URL shortener using ASP.NET WepAPI and MVC: error handling
In the two previous post I discussed about the first step to creare this application and the implementation of the business logic. Now we can implement the error handling. We have two custom exception classes: ShorturlConflictException (when a segment already exists) and ShorturlNotFoundException (when a segment isn’t found in the database). There is also a third type: an unexpected exception, for example when there is no database connection. Normally, the user will see these errors. We have to build a mechanism where these exceptions are caught and a nice error…
Creating a URL shortener using ASP.NET WepAPI and MVC: implementing the business layer
In my previsious post I discussed the first implementation of this application. In this post I’m explained how to implement the business layer. First of all you make sure the Business project references the Data, Entities and Exceptions projects. In the Exceptions project you add two new classes: ShorturlConflictException using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace PSC.Shorturl.Web.Exceptions { public class ShorturlConflictException : Exception { } } ShorturlNotFoundException using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace PSC.Shorturl.Web.Exceptions { public class ShorturlNotFoundException : Exception {…
Creating a URL shortener using ASP.NET WepAPI and MVC
In this tutorial, I use several techniques and tools. I use Microsoft Visual Studio 2015 and the latest version of all components. ASP.NET MVC: Microsoft’s modern web application framework. As the name says, it pushes you to use the MVC (model view controller) software design principle. ASP.NET Web API: Web API and MVC are used together in many applications. With MVC, the HTML of the web pages are rendered on the server, and with Web API you can, like the name says, create an API. Web API also uses the…
How do I get a Unique Identifier for a Device within Windows 10 Universal?
If you google a bit about this problem, you can’t find a right solution because all people are speaking about Hardware Token. Unfortunately this functionality doesn’t exists for Universal Windows Application. There are at the moment only a way. You have to add the Extension reference “Windows Desktop Extensions for the UWP” or “Windows Mobile Extensions for the UWP“, then you can use the following code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using Windows.Security.ExchangeActiveSyncProvisioning; using Windows.System.Profile; namespace PSC.Code { public sealed class DeviceInfo { private static…
Console Progress Bar with C#
The progress of these applications with a simple incremental percentage display. I’d create a generic method which would display an ASCII progress bar
PSC.Search: a new implementation of Levenshtein distance algorithm
This article describes a simple implementation of the string search. It can be used for approximate string matching (for more information, see https://en.wikipedia.org/wiki/Fuzzy_string_searching). Other algorithms for approximate string searching exist (e.g., Soundex), but those aren’t as easy to implement. The algorithm in this article is easy to implement, and can be used for tasks where approximate string searching is used in an easy way. The algorithm used the Levenshtein-distance for determining how exact a string from a word list matches the word to be found. Information about the Levenshtein-distance can…
Writing Custom HTML Helpers for ASP.NET MVC
As a web forms developer, I found the transition to MVC to be a bit of a shock at first. Without fully understanding the nature of MVC, I found the lack of a Toolbox filled with server controls to be confusing. However, once it became clear that the goal of MVC was to expose HTML markup and give developers full control over what is rendered to the browser, I quickly embraced the idea. Transitioning from Web Forms In MVC development, HTML helpers replace the server control, but the similarities aren’t…
Implementing Role Based Menu in ASP.NET MVC
In default template of asp.net mvc 4.0, Layout.cshtml has following code for menu: <nav> <ul id=”menu”> <li>@Html.ActionLink(“Home”, “Index”, “Home”)</li> <li>@Html.ActionLink(“About”, “About”, “Home”)</li> <li>@Html.ActionLink(“Contact”, “Contact”, “Home”)</li> </ul></nav> Which is hard-coded for all users. We’ll create partial view for menu to reduce complexity. Right click on Shared folder in Views > select Add > click ViewEnter Name: _Menu and set “Create as a partial view†option true > click AddIt’ll open blank cshtml page. Define Menu Items: In normal asp.net webforms app, Sitemap file is used to define structure. Here we’ll define…
Make the application loosely coupled
In this series of tutorials, we build an entire Contact Management application from start to finish. The Contact Manager application enables you to store contact information – names, phone numbers and email addresses – for a list of people. We build the application over multiple iterations. With each iteration, we gradually improve the application. The goal of this multiple iteration approach is to enable you to understand the reason for each change. Iteration #1 – Create the application. In the first iteration, we create the Contact Manager in the simplest…
Add form validation ASP.NET MVC
Building a Contact Management ASP.NET MVC Application (C#) In this series of tutorials, we build an entire Contact Management application from start to finish. The Contact Manager application enables you to store contact information – names, phone numbers and email addresses – for a list of people. We build the application over multiple iterations. With each iteration, we gradually improve the application. The goal of this multiple iteration approach is to enable you to understand the reason for each change. Iteration #1 – Create the application. In the first iteration,…
Parse HTML page and capture contents
Here I show a simple class that receives the HTML string and then extracts all the links and their text into structs. It is fairly fast, but I offer some optimization tips further down. It would be better to use a class. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Text.RegularExpressions; using System.Threading.Tasks; namespace PSC { public class Finder { public struct LinkItem { public string Href; public string Text; public override string ToString() { return Href + “\n\t” + Text; } } public class LinkFinder { public static…
Log record changes in SQL server in an audit table
How to implement a log record changes in SQL server in an audit table and Entity Framework. This is the easy explanation and the code
Working With Share Link Task in Windows Phone 8
In this article we will learn about the Share Link Task. This task enables the user to share a link from the app itself on various social media and other sharing platforms. It can be a very useful feature for promoting your app on various platforms. Let’s see how to use it. Share Link Task This is a kind of launcher provided by Windows Phone to launch the share screen from an app so that the user can share the link. The task can be customized with various properties for…
C# string to Formatted HTML string
Is there a tool out there that can turn a C# string of unformatted HTML (no indentions, no new lines, etc) into a Formatted HTML string?I am in a situation where I am generating an HTML string, and I am outputting it into a multiline textbox. Write now, it is wrapping, but is showing up similar to a paragraph. I would like it to be shown as formatted HTML? It wouldn’t even have to be very nice formatting, but at least not show a paragraph of HTML.For having a good…