.Net Tips : Convert DataTable object to list of class object using LINQ with C#.Net and VB.Net example

You can fill List of object from DataTable using LINQ. There are many situations where you need to get data from DB into data table and after that from data table to proper class object. We can do this easily with LINQ.

Here is example for this.
In this example we take one DataTable object which contains two columns 'product_id' and 'product_name'. This DataTable has many rows. Now we want to convert DataTable object into list of class object. We have one Class 'clsProduct' which has two property 'product_id' and 'product_name'. Now we transform DataTable object data in to list of clsProduct class object using LINQ.

MVC Tips : Implement IValidatableObject Interface for custom validation in ASP.Net MVC 4

Click Here to Download ImplementIValidateObjectInterfaceInMVC.zip Example.

We can validate model itself by implementing IValidatableObject Interface. For validation you need to implement 'Validate' method of IValidatableObject Interface.

Here is some difference from the attribute validation version.

• In this for validation method is 'Validate' instead of 'IsValid' and also return type and parameter is different.
• The return type for Validate is an IEnumerable<ValidationResult>, because the logic inside this method is validating the entire model and might need to return more than a single validation error.
• No parameter is passed to Validate because you  can directly access model properties because this Validate method is inside model.

Here is example for this.

.Net Tips : Attach and Raise events on XML document object with C#.Net and VB.Net example

You can attach events like 'onChanging' and 'onChanged' events on XML document object. These events raise when you 'ADD' or 'REMOVE' XML element from XML Document object.

First 'onChanging' event raise after that 'onChanged' event raise. In this event we get 'XObjectChangeEventArgs' class object. This object give us property like 'ObjectChange'. In this property we can know that which method is performed.

When we call 'Add' method we get 'Add' value in 'ObjectChange' property and when we call 'Remove' method we get 'Remove' value in 'ObjectChange' property.

Here is example on this.

MVC Tips : Custom Annotation validation in ASP.Net MVC 4

Click Here to Download CustomAnnotationInMVC.zip Example.

You can write your own custom annotations in MVC 4.
Here we can do custom validation using custom annotations. Custom annotations validation derive from the ValidationAttribute base class. This base class available in 'System.ComponentModel.DataAnnotations' namespace. ValidationAttribute class is abstract class.

For custom validation you need to write your own class and inherit ValidationAttribute class. After that, you need to override IsValid Method. IsValid Method has two parameters 'Value' and 'ValidationContext'.

• Value : Which contains your data, which is going to validate.
• ValidationContext : This parameter is very important. This content information like model object instance, model type friendly display name and other information

In this method you write your own logic for validate data and return result. If value is validate at that time you need to return this 'ValidationResult.Success' else you return result like 'return new ValidationResult(your custom error message)'

C# Tips : Validate or Verify XML File Data using LINQ and REGEX with C#.Net and VB.Net example

You can validate the data of XML file and identify XML elements which are failed to validate. We can easily achieve this using LINQ.

Here is example for this.
In this example we take one 'customer.xml' file. In this file we have 'name' and 'phone' element. We need to validate phone number with REGEX and display it's validate result either it is true or false.

C# Tips : Check XML element has attribute using LINQ with C#.Net and VB.Net example

Using LINQ you can check that attribute exist in element or not. There is property called "HasAttributes" of XElement class to check existence of attribute.

Here is example for this.

In this example we take one 'customers.xml' file which contains customers information like name, id, etc. Now we check that does "customer" element has 'id' attribute or not. In XML there is one customer 'David' which does not have 'id' attribute. Now we iterate each 'customer' element and display that it element has attribute or not.

C# Tips : Sort or order by Date in XML File data using LINQ with C#.Net and VB.Net example

 XML file contains various types of data like string, integer, date, etc. Now if we want to get data from XML file order by some attribute which contains dates at that time we need to do some special things if we are not doing that at that time data is not sorted date wise it will treat as normal string sorting. We can do date wise sorting. 

Here are examples for this.
In this example we are taking on 'Books.xml' file which contains books details in this XML file for each book element we are one "ReleaseDate" element which contains date value. Now we take that XML file in XMLDocument object and sort on "ReleaseDate" attribute by converting that string date into date datatype.