如何检测iOS短信功能（一般不发短信）

Question

I'm writing an app that optionally allows you to send an SMS to a list of users. The app currently detects whether the device allows the sending of text messages using MFMessageComposeViewController.canSendText() and only displays the "Send SMS" button when the result is true.

Today, one of my users complained that when he hit the button on his Wifi-only iPad, nothing happened. As it turns out, canSendText() also returns true if the iOS device has the iMessage capability turned on, even if SMS is not supported. Turning the iMessage capability off in the iOS setting properly disables the "Send SMS" button.

The problem with sending the message via iMessage is that some recipients will have iMessage turned on and thus will receive the text message. But for the recipients without iMessage (it may be turned off or they may not be using an Apple device in the first place), those messages will not arrive. (When the MFMessageComposeViewController eventually comes up, those addresses are marked in red. But my average user is not going to understand that this means the message will not delivered.)

Does anybody know of a reliable method that tests for SMS capability specifically, not just for text messages (SMS, iMessage and MMS) in general?

Answer 1

As far as I know devices with iOS 5+ will return TRUE for MFMessageComposeViewController.canSendText() as they are capable of iMessage

So I assume you only need to send text if SIM card is installed on device. But there is no way to detect if SIM card is installed on device. Still you can use workaround like :

#import<CoreTelephony/CTCallCenter.h>
#import<CoreTelephony/CTCall.h>
#import<CoreTelephony/CTCarrier.h>
#import<CoreTelephony/CTTelephonyNetworkInfo.h>

CTTelephonyNetworkInfo* info = [[CTTelephonyNetworkInfo alloc] init];
CTCarrier* carrier = info.subscriberCellularProvider;
NSString *mobileCountryCode = carrier.mobileCountryCode;
NSString *carrierName = carrier.carrierName;
NSString *isoCountryCode = carrier.isoCountryCode;
NSString *mobileNetworkCode = carrier.mobileNetworkCode;

NSLog(@"\n %@ \n %@ \n %@ \n %@", mobileCountryCode, carrierName, isoCountryCode, mobileNetworkCode);

Here, carrierName will return name when SIM card is present OR last use SIM card info. But others will be null if there is no SIM card installed.