// 拨打电话 
+ (void)callPhone:(NSString *)phoneNum { 
  
 if ([ISNULL(phoneNum) length] == 0) { 
  [SVProgressHUD showErrorWithStatus:@"拨打失败，手机号码不存在" duration:1.0 dismiss:nil]; 
  return; 
 } 
  
 NSString *callPhone = [NSString stringWithFormat:@"telprompt://%@", phoneNum]; 
  
 /// 解决iOS10及其以上系统弹出拨号框延迟的问题 
 /// 方案一 
 if ([[UIDevice currentDevice].systemVersion floatValue] >= 10.0) { 
  /// 10及其以上系统 
  [[UIApplication sharedApplication] openURL:[NSURL URLWithString:callPhone] options:@{} completionHandler:nil]; 
 } else { 
  /// 10以下系统 
  [[UIApplication sharedApplication] openURL:[NSURL URLWithString:callPhone]]; 
 } 
  
 /// 方案二 
// dispatch_async(dispatch_get_global_queue(0, 0), ^{ 
//  [[UIApplication sharedApplication] openURL:[NSURL URLWithString:callPhone]]; 
// }); 
  
}