iOS 10拨打系统电话发现弹出框会延迟2s左右出现，很不爽，研究了一下，发现是openURL在http://blog.csdn.net/syg90178aw/article/details/68926603及其之后会阻塞主线程
所以，拨打电话前，做个判断，来代码,
方案一：
```
// 拨打电话
+ (void)callPhone:(NSString*)phoneNum {
if(phoneNum.length==0) {
return;
}
NSString*callPhone = [NSStringstringWithFormat:@"telprompt://%@",phoneNum];
NSComparisonResult compare = [[UIDevicecurrentDevice].systemVersioncompare:@"10.0"];
if(compare == NSOrderedDescending || compare == NSOrderedSame) {
/// 大于等于10.0系统使用此openURL方法
[[UIApplicationsharedApplication]openURL:[NSURLURLWithString:callPhone]options:@{}completionHandler:nil];
}else{
[[UIApplicationsharedApplication]openURL:[NSURLURLWithString:callPhone]];
}
}
```
方案二
```
// 拨打电话
+ (void)callPhone:(NSString*)phoneNum {
if(phoneNum.length==0) {
return;
}
NSString*callPhone = [NSStringstringWithFormat:@"telprompt://%@",phoneNum];
dispatch_async(dispatch_get_global_queue(0,0), ^{
[[UIApplicationsharedApplication]openURL:[NSURLURLWithString:callPhone]];
});
}
```
关于拨打电话的方法，自己凭喜好选择，导致弹出框延迟的原因，目前初步诊断就是openURL在iOS 10及其之后会阻塞主线程
原文：http://blog.csdn.net/syg90178aw/article/details/68926603
