For server-side code, the HTML code to generate a bunch is a bunch of strings, there is no meaning, only to the browser execution makes sense
127.0.0.1 is the loopback address (the LoopBack), it is represented by a loopback address to access the machine, even if it is outside the network address of the machine can not access. localhost is 127.0.0.1 alias. It is not accessible externally.
0.0.0.0 any IP (Any IP), do not write the IP death bound by any piece of card can access the network program.
In the browser you can accomplish things, do not do it to the server.
<Asp: Button is concerned, onclick is a server-side event, OnClientClick onclick code that is ultimately generated to the client browser.
Reproduced in: https: //my.oschina.net/u/164404/blog/210632