Understanding of ispostback in ASP. NET

1. Official explanation of ispostback:

Gets a value that indicates whether the page is first rendered or loaded in response to sending back.

If the page is loaded in response to the client sending back, it is true; otherwise, it is false.

2. perform the following experiments:

 
Protected void page_load (Object sender, eventargs e) {If (! Ispostback) {this.txt hidden. value = "! Ispostback ";}} protected void button#click (Object sender, eventargs e) {response. write ("<SCRIPT type = 'text/JavaScript '> alert ('" + this.txt hidden. value + "'); </SCRIPT> ");}
 

Result :! Ispostback

Slightly changed

 
Protected void page_load (Object sender, eventargs e) {If (! Ispostback) {this.txt hidden. value = "! Ispostback ";} else {this.txt hidden. value = "ispostback" ;}} protected void button#click (Object sender, eventargs e) {response. write ("<SCRIPT type = 'text/JavaScript '> alert ('" + this.txt hidden. value + "'); </SCRIPT> ");}
 

Result: ispostback

Here, if you need to assign a value to the control during page loading! Ispostback;

The page logic operation can change the control value in ispostback.

 

To be continued...