禁用控件的ViewState，設置控件的EnableViewState="False"即可；禁用Form的ViewState：<%@ Page EnableViewState="False" %>；設置ViewState的值：ViewState( "SomeItem" ) = "Some Value"；ViewState是區分大小寫的，比如Response.Write( ViewState( "Count" ) )和Response.Write( ViewState( "count" ) )是不一樣的。
By default, almost all ASP.NET controls retain the values of their properties between form posts. For example, if you assign text to a Label control and submit the form, when the page is rendered again, the contents of the Label control are preserved.
The magic of view state is that it does not depend on any special server or browser properties. In particular, it does not depend on cookies, session variables, or application variables. View state is implemented with a hidden form field called VIEWSTATE that is automatically created in every Web Forms Page.
Disabling View State：for example, uses the EnableViewState property to disable view state for a Label control. When the page is first loaded, a message is assigned to the Label control and the message is displayed. If you click the button, however, and reload the page, the text disappears from the label.Instead of disabling view state control by control, you also can disable view state for the whole page. You should do so when you are not taking advantage of view state and the controls in a page contain a lot of data. To disable view state for an entire page, modify the EnableViewState attribute of the Page directive.：<%@ Page EnableViewState="False" %>
Adding Values to View State ：To add a value to the state bag, use a statement such as the following:ViewState( "SomeItem" ) = "Some Value"。This statement adds a new item to the state bag class named SomeItem with the value Some Value.
ViewState is case-sensitive. The following two statements are not equivalent:
Response.Write( ViewState( "Count" ) ) Response.Write( ViewState( "count" ) )