code for how to perform calling and cancel the calling in iphone

I am new to developing iPhone applications.

I am looking for an example on calling phone numbers, specifically starting a call and ending one.

Is this possible ? If so, how would one accomp开发者_开发技巧lish this ?

Here is the code to make a call

[[UIApplication sharedApplication] openURL:[NSURL URLWithString: @"tel:1-800-ACCE-PTME"]];

Anything that modifies a user's ability to block phone calls is going to run afoul of Apple's basic approach to third-party apps. There are a lot of things that are questionable and you might get away with. Blocking calls is clearly forbidden.

 [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"tel:374347347"]];

I don't think Apple allows you to cancel calls from within your app.