iOS-拨打电话

http://blog.csdn.net/ouy_huan/article/details/30506925 借鉴于此，谢谢
1、这种方法，打完电话后还会回到原来的程序，也会弹出提示，推荐这种

NSMutableString * str=[[NSMutableString alloc] initWithFormat:@"tel:%@",@"182xxxxxxxx"];
UIWebView * callWebview = [[UIWebView alloc] init];
[callWebview loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:str]]];
[self.view addSubview:callWebview];

2、这种方法，挂断电话会在原来的应用，而且是直接拨打，不弹出提示

NSMutableString * str=[[NSMutableString alloc] initWithFormat:@"tel:%@", @"电话号码"];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];

此方法可以自己定义提示信息：

UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"提示" message:[NSString stringWithFormat:@"拨打该电话按照正常资费由运营商收取：%@", @"182xxxxxxxx"] preferredStyle:UIAlertControllerStyleAlert];
        UIAlertAction *action1 = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            [alert dismissViewControllerAnimated:YES completion:^{
                NSLog(@"取消拨打电话");
            }];
        }];
        UIAlertAction *action2 = [UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            NSMutableString * str=[[NSMutableString alloc] initWithFormat:@"tel:%@", @"182xxxxxxxx"];
            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];
        }];
        [alert addAction:action1];
        [alert addAction:action2];
        [self presentViewController:alert animated:YES completion:^{
            NSLog(@"弹出拨打电话号码弹框");
        }];

3,这种方法也会回去到原来的程序里（注意这里的telprompt），也会弹出提示

NSMutableString * str=[[NSMutableString alloc] initWithFormat:@"telprompt://%@", @"182xxxxxxxx"];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];