问题
First, my app worked fine on iOS 7, since iOS 8 i can't send in-app email thru "MFMailComposeViewController". Message window comes up, only shows subject of the mail and closes within seconds. I found this thread here which describes my problem and now tried to implement the answer from "Joe Blow" https://stackoverflow.com/a/25864182/4061869
But im getting some errors, some sematic and parse issues.
Worst thing according to this part of the workaround:
Of course have this in your Prefix file
#define APP ((AppDelegate *)[[UIApplication sharedApplication] delegate])
// it's worth noting that is the delegate, not the "application"
Leads to this error:
Use of undeclared identifier 'AppDelegate'
Anyone knows where the problem can be? I tried different wordings on 'AppDelegate' according to my filename of the appdelegat.h/.m but nothing helps.
回答1:
You can define the app delegate in whichever ViewController you are working in, by using:
AppNameAppDelegate *APP = [[UIApplication sharedApplication]delegate];
To state the obvious, by AppName I mean the name of your application. Make sure to import the AppDelegate.h into your .m file too.
#import "AppNameAppDelegate.h"
For the record, I am also having the same issue with MFMailComposeViewController,and I have tried the method suggested in the post you linked (creating a global mail composer), but it still won't work for me using the iOS 8 simulator. Apparently it works on a physical device running iOS 8, but I personally cannot confirm that just yet.
来源：https://stackoverflow.com/questions/25953103/mfmailcomposeviewcontroller-in-ios-8