Windows innovation interview Summary (1)

Windows innovation interview Summary (1)

Time: 2011/11/2

1. What is generic?

Definition: it provides more than one typeCode. Generics allow us to declare code for Type parameterization, And we can instantiate it with different types. Generic is a class template.

2. What is delegation? And the benefits of using delegation?

Delegate: A delegate is a list of ordered methods with the same signature and return value types. When a delegate is called, each method in the method list is called in sequence.

Advantages of using delegation:

Use DelegationProgramThe delegate can encapsulate the method in the delegate object, and then pass the delegate objectThe code of the referenced method, instead of knowing which method to call at compilation.

Extension: the difference between a delegate and an event:

A delegate is a type, and an event is an object, which is not comparable.

3. What are the improvements of the. netframework3.5 framework to the 2.0 Framework?

1> language integrated query is a set of extensions used for C # language. ItAllows you to write C # code to directly operate the database. There are three types of data: LINQ to objects, LINQ to dataset, and LINQ.

Entities.

2> Ajax support.

3. ASP. NET page processing?

More professional: the lifecycle of a page.

There are the following phases:

1> the browser sends a request.

2> page framework initialization. The page. init event is triggered.

3> User code initialization. The page. Load event is triggered.

4> automatic verification. The page. isvalid attribute checks whether all verification controls in the form pass.

5> event processing. ASP. NET triggers all events that occur after the last release.

6> the browser accepts the response.

7> clear (close ). Trigger the page. Unload event first .. The garbage collector of netframework recycles resources, and the page. Disposed event is triggered.

4. Database paging?

The core technology for implementing database paging is to limit the number of rows in the result set.

Idea: 1> set two attributes. pagesize indicates the number of data entries on each page, and currentindex indicates the current page number (counted from 0 ).

Four buttons: Home Page, Previous Page, next page, and last page.

2> pagesize * The pagesize entry starting with currentindex is the data on the current page.

3> when you click the homepage button, set currentindex to 0.

When you click the previous page button, currentindex is set to CurrentIndex-1.

When you click the next page, set currentindex to currentindex + 1.

When you click the last page button, currentindex is set to the total number of entries/pagesize.

5. What are the functions of having and where statements in SQL? Used for Data Filtering

1> the having statement is used to filter data in a group. For example, you can only query the age group where the number of queried users is greater than 1.

For example, select age, count (*) as countofthisage from tb_employee group by Fage having count (*)> 1;

2> when having statements are used, group by should be placed after having statements; when where statements are used, group by should be placed before where statements.

6. What is the problem about Div + CSS layout?

Let's talk about the "box model"

The box model mainly defines four areas:

1> content)

2> border distance and padding attributes.

3> border, border attribute.

4> margin, margin attribute.

7. What selectors does jquery have?

The four selectors are:

Basic selector: 1> wildcard selector. $ ("*")

2> tag selector. $ ("Div ")

3> ID selector. $ ("#")

4> class selector. $ (".")

5> group selector. $ ("Div, span, P ")

Hierarchy selector: 1> descendant element selector. $ ("Div span ")

2> child element selector. $ ("Parent Child ")

3> adjacent element selector. $ ("Prev + next ")

4> sibling element selector. $ ("Prev ~ Siblings ")

Filter selector: 1>: first. $ ("Div: First ")

2>: Last. $ ("Div: Last ")

...

Form selector: 1>: input. $ (": Input ")

2>: text. $ (": Text ")

...