How to use Visual Studio to build a web service with ASP.NET in C#
You can use Visual Studio to build a web service and in this case you will not go through the process described in the articles How to build basic web service with ASP.NET in C# – step 1 , How to build basic web service with ASP.NET – step 2, and How to build basic web service with …
You can use the article How to build basic web service with ASP.NET – step 2 to verify that the class developed by you is ready for the Web. You will learn from this article how to convert it to a web service. In this case the BookService class described in the article How to build …
Each web service begins as a stateless class with one or more methods that the remote clients call to invoke your code.
BookService is designed to allow remote clients to retrieve information about books provided by the store. The class provides GetBooks() method that returns a DataSet with the full set of books information. It …
How to use calculated columns with the ADO.NET DataView in C#
Calculated columns are used when you want to represent a value that’s computed using a combination of existing values. You can create a calculated column, by following the next steps:
1. Create DataColumn object by specifying its name and type.
2. Set the Expression …
How to filter data based on relationships with the ADO.NET DataView in C#
The article How to filter data with the ADO.NET DataView in C# does not cover one of little-known features of the DataView to filter data rows based on relationships. For example, you need to display categories that contain more than five products, or you need to display customers who have bought more than 5 bank products. …
If in your project you want to include only certain rows in the display you can use a DataView to apply custom filtering. To accomplish this, you should use the RowFilter property which acts like a WHERE clause in a SQL query. You can limit the final results by using it and by applying logical operators, …
If in your project you need to sort data by using ADO.NET DataView you can use the next example as a basic. The example uses a page with three GridView controls. When the page loads, it binds the same DataTable to each of the grids. However, it uses three different views, each of which sorts the results using …
There is a threat for file access named path canonicalization. Canonicalization is a process for converting data in standard (or canonical) form and it refers to the action that builds a path in a safe form. The next picture shows this process:
Path canonicalization in action. If an attacker passes special characters, such as .. or …
How to handle and display user input to protect ASP.NET web application from XSS in C#
Cross site scripting (or XSS) is the most insidious kind of attack because it’s quite often invisible at first glance. XSS is based on some code (markup or JavaScript) that is injected into your page. The most common is related to that’s saved in a database after end user input and then loaded in a page. The next …
You can use approach described in the article How to handle improper parameter values in ASP.NET in C# to create a blocking engine to handle and improve parameter values. You should manage invalid requests and notify the client about any invalid parameters that were passed in. You should reply to the request using one of the …