Static variables on the Asp.net page

Refer. It can be said that all instances of this class share a static variable. The Asp.net page is a class, and we access a page. An instance of this class will be instantiated on the server to respond to our requests. "All instances share a static variable", which means that the static variable on the Asp.net page accessed by all clients is the same variable.

Every time we access the Asp.net page, it is a brand new object, not the object we accessed last time. Therefore, the changes to the variables on the page were not retained during the last page access. When this problem occurs, many beginners intuitively declare this variable as static. During the test, they find that the page status is actually retained.

TestCodeAs follows:

View code

 Public     Partial     Class  _ Default: system. Web. UI. Page
{
  Private    Static     String  STR;
  Protected     Void  Page_load (  Object  Sender, eventargs E)
{
  If  (  !  Ispostback)
{
Str  =    "  This is a static variable value assignment.  "  +  Datetime. now;
}
}
  Protected     Void  Button#click (  Object  Sender, eventargs E)
{
  This  . Textbox1.text  =  STR;
}
} 

I used Firefox to open three pages in a row and click the button to display the same value (assign the connection value to IE and then change it)

View code

 Public     Partial     Class  _ Default: system. Web. UI. Page
{
  //  Private Static string STR;  
    Protected     Void  Page_load ( Object  Sender, eventargs E)
{
  If  (  !  Ispostback)
{
  //  STR = "this is a static variable value assignment" + datetime. now;  
  Viewstate [  "  Key  "  ]  =    "  This is a static variable value assignment.  "     +  Datetime. now;
}
}
  Protected     Void  Button#click (  Object  Sender, eventargs E)
{
  This  . Textbox1.text  =  Viewstate [ "  Key  "  ]. Tostring ();
}
} 

Changed to viewstate.