iOS打电话（有无提示功能）

一、有提示窗口

    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];

二、无提示窗口

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