iOS打电话（有无提示功能）

NSMutableString * str = [[NSMutableString alloc]initWithFormat:@"tel:%@",<span style="font-family: Arial, Helvetica, sans-serif;">@"电话号码"</span>];
UIWebView * callWebView = [[UIWebView alloc]init];
[callWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:str]]];
[self.view addSubview:callWebView];

NSMutableString * str = [[NSMutableString alloc]initWithFormat:@"tel:%@",@"电话号码"];

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];