Postback and Stateview

andreas5 · August 2nd, 2010, 09:22 AM

Hello, first of all i would like to thank Imar for a awesome and very easy to read book.
It is probably the best book i have worked with.

I just read about postback and stateview in chapter 4, and i understand why it exists,
but i have some questions about what information is sent from the client to the server in a postback.

Are my following two statements correct?

- The stateview is only stored at the client and then sent with every postback,
is updated on the server if needed, and then sent back to the client.

- Everything inside <form> is sent to the server during a postback.

I probably dont need to know this in detail but i couldnt stop thinking about it

Imar · August 2nd, 2010, 09:37 AM

Quote:

Are my following two statements correct?

More or less....

Quote:

The stateview is only stored at the client and then sent with every postback, is updated on the server if needed, and then sent back to the client.

Yes, ViewState is sent to the client when the page is done at the server. Whatever data is stored in ViewState is serialized (converted to characters basically so it can be stored in a hidden field) and sent back to the server after a postback. There it's used to recreate control state. When the page is sent to the client again, the new ViewState for that page is serialized and sent to the browser.

Quote:

Everything inside <form> is sent to the server during a postback.

Not everything; but controls that are designed to do this. E.g. the values of HTML controls such as <input type="text" />, <select />, <textarea /> and so are submitted to the server. Other elements, such as labels (<span /> elements) and text are not submitted to the server.

Hope this helps,

Imar

andreas5 · August 2nd, 2010, 10:13 AM

Alright, thanks!

btcomp · August 6th, 2010, 09:50 AM

I had to go over ViewState at least a couple of times. But I am beginning to understand, and I agree turn off ViewState except when you really need it.