View State

View State is the method to preserve the Value of the Page and Controls between round trips. It is a Page-Level State Management technique. View State is turned on by default and normally serializes the data in every control on the page regardless of whether it is actually used  during a post-back. 

Features Of View State

These are the main features of view state:

1. Retains the value of the Control after post-back without using a session.
2. Stores the value of Pages and Control Properties defined in the page.
3. Creates a custom View State Provider that lets you store View State Information in a SQL Server Database or in another data store.

Data Objects That Can be Stored in View state

1. String
2. Boolean Value
3. Array Object
4. Array List Object
5. Hash Table 
6. Custom type Converters

Advantages of View State

1. Easy to Implement.
2. No server resources are required: The View State is contained in a structure within the page load.
3. Enhanced security features: It can be encoded and compressed or Unicode implementation.

Disadvantages of View State

1. Security Risk: The Information of View State can be seen in the page output source directly. You can manually encrypt and decrypt the contents of a Hidden Field, but It requires extra coding. If security is a concern then consider using a Server-Based state Mechanism so that no sensitive information is sent to the client.
2. Performance: Performance is not good if we use a large amount of data because View State is stored in the page itself and storing a large value can cause the page to be slow.
3. Device limitation : Mobile Devices might not have the memory capacity to store a large amount of View State data.
4. It can store values for the same page only