asp.net 3.5

How to use LINQ Skip clause in VB.NET

Web developers use optional LINQ Skip clause when they want to bypass, specified by the count parameter, elements at the beginning of a results list and return the remaining elements. Web developers can combine the Skip clause with the Take clause to return a range of data from any segment of a query, by passing the …

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How to use LINQ Distinct clause in VB.NET

Web developers use optional LINQ Distinct clause when they want to receive a list of unique items. The Distinct clause ignores duplicate query results and can be applied to duplicate values for all return fields specified by the Select clause. If no Select clause is specified, the Distinct clause is applied to the range variable for the query …

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How to use LINQ Let clause in VB.NET

Web developers can use optional LINQ Let clause to compute values for each query result and reference them by using an alias. The alias can be used in other clauses, such as the Where clause. By using Let clause, Web developers can create a query statement that is easier to read because they can specify an alias for …

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How to use LINQ multiple joins

Web developers use LINQ join clause when they want to associate elements from different source sequences that have no direct relationship in the object model. For example, an electronic devices distributor might have a list of suppliers of a certain product, and a list of buyers. A join clause can be used, for example, to create a list …

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How to use Validation groups in ASP.NET 4.0

In more complex pages, you may want to perform validation separately, by using several distinct groups of controls, possibly in separate panels. ASP.NET 4.0 enables this scenario with a feature called validation groups. To create a validation group, you need to put the input controls and the CausesValidation button controls into the same logical group. You can do …

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How to use CustomValidator control in ASP.NET 4.0

You can use the CustomValidator control to execute your custom client-side and server-side validation routines. You can associate them with the control so that validation is performed automatically. If the validation fails, the Page.IsValid property is set to false, as occurs with any other validation control.

 

The client-side and server-side validation routines for the CustomValidator are declared similarly. They …

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How to use LINQ inner join clause based on a composite key

Web developer uses LINQ join clause when he/she wants to associate elements from different source sequences that have no direct relationship in the object model. For example, an electronic devices distributor might have a list of suppliers of a certain product, and a list of buyers. A join clause can be used, for example, to create a list …

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How to use LINQ inner join clause based on a simple key

Web developers use LINQ join clause when he/she wants to associate elements from different source sequences that have no direct relationship in the object model. For example, an electronic devices distributor might have a list of suppliers of a certain product, and a list of buyers. A join clause can be used, for example, to create a list …

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How to use RegularExpressionValidator control in ASP.NET 4.0

The RegularExpressionValidator is one of ASP.NET’s most powerful validation controls. It validates text by determining whether it matches a specific pattern. All regular expressions consist of two kinds of characters:

– Literals – represent a specific defined character

– Metacharacters –  characters for special use.

When you are going to use RegularExpressionValidator you should develop regular expression …

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How to create a manual validation in ASP.NET 4.0

You can create a manual validation in one of the three ways:

– Use your own code to verify values. In this case, you will not use any of the ASP.NET validation controls.

– Disable the EnableClientScript property for each validation control. This allows an invalid page to be submitted, after which you can decide what …

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