IOS6/iOS7, 3.5 inch/4.0 inch, ios6ios7

IOS6/iOS7, 3.5 inch/4.0 inch, ios6ios7

Retina (3.5/4 inch Screen) or Non-Retina judgment

if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {    if ([[UIScreen mainScreen] scale] == 2.0) {       if([UIScreen mainScreen].bounds.size.height == 568){          // iPhone retina-4 inch        } else{         // iPhone retina-3.5 inch        }}else {    // not retina display}

IOS6/iOS7 judgment

NSString *ver = [[UIDevice currentDevice] systemVersion]; float ver_float = [ver floatValue]; if (ver_float >= 7.0) {    //iOS >=7 } else{    //iOS <7  }

How can I restore the iPhone 4 to ios613 after ios7 is upgraded? ios7 is too slow, too difficult, and I want to die.

I am very responsible for telling you that your iPhone will definitely be able to downgrade. For details, please refer to the post I answered earlier. iPhone4 has escaped from prison and has to be downgraded.
 
How does IOS7 return to IOS613? For iPhone 4

First, you need to know whether you have backed up the shsh file of ios6. If yes, you can restore it on a self-built server. If the shsh file has not been backed up in jailbreak mode, you can only wait for the official version of ios7, and it should come out soon. I'm just waiting for the official version of ios7 .... There should be a beta3 of ios7 in the next week, and many bugs will be fixed. The landlord can wait and upgrade beta3, which may be slightly better. Good luck.