How to: determine how to call ASP. NET web pages

It is usually necessary to know how to call ASP. net webpage: called by the original request (http get), http post, and cross-page sending (http post) from other pages, or from other pages (Use Method or use the callback in the browser. Class exposure can be used to determine the property set of the page call method.

Determine how to call ASP. NET web pages

• Check the values of the following page class attributes, and then determine the page calling method by referring to the following table:

  The following table lists the page call method and corresponding page attribute values.

  Call Method	Attribute Value
  Original request	Set ispostback to false. Set previouspage to null (nothing in Visual Basic ). Set iscallback to false.
  Resend	Ispostback is set to true. Set previouspage to null (nothing in Visual Basic ). Set iscallback to false.
  Send across pages	Set ispostback to false. Previouspage references the Source Page. Iscrosspagepostback is set to true. Set iscallback to false.
  Server Transmission	Set ispostback to false. Previouspage references the Source Page. Set iscrosspagepostback referenced in previouspage to false. Set iscallback to false.
  Callback	Set ispostback to false. Set previouspage to null (nothing in Visual Basic ). Set iscallback to true.

  Note:
  Make sure that the iscrosspagepostback attribute of the page referenced in previouspage is tested. The iscrosspagepostback attribute of the current page always returns false.