iOS调用打电话，发短信，打开网址

//1、调用 自带mail
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"mailto://admin@CodeSnippet.cn"]];

//2、调用 电话phone
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"tel://8008808888"]];

//3、调用 SMS
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"sms://800888"]];

//4、调用自带 浏览器 safari
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"http://outofmemory.cn