#define IsIOS8 (NSFoundationVersionNumber > NSFoundationVersionNumber_iOS_7_1)

#define IsIOS8 (NSFoundationVersionNumber > NSFoundationVersionNumber_iOS_7_1)

float deviceOSVersion = [[[UIDevice currentDevice] systemVersion] floatValue];
float versionToBeCompared = 3.1.3; //(For Example in your case)

if(deviceOSVersion < versionToBeCompared)
   //Do whatever you need to do. Device version is lesser than 3.1.3(in your case)
else 
   //Device version should be either equal to the version you specified or above

基本上和这个想法一样https://stackoverflow.com/a/19903595/1937908但更健壮:

#ifndef func_i_system_version_field
#define func_i_system_version_field

inline static int i_system_version_field(unsigned int fieldIndex) {
  NSString* const versionString = UIDevice.currentDevice.systemVersion;
  NSArray<NSString*>* const versionFields = [versionString componentsSeparatedByString:@"."];
  if (fieldIndex < versionFields.count) {
    NSString* const field = versionFields[fieldIndex];
    return field.intValue;
  }
  NSLog(@"[WARNING] i_system_version(%iu): field index not present in version string '%@'.", fieldIndex, versionString);
  return -1; // error indicator
}

#endif

只需将上面的代码放在一个头文件中。

用法:

int major = i_system_version_field(0);
int minor = i_system_version_field(1);
int patch = i_system_version_field(2);

Try:

NSComparisonResult order = [[UIDevice currentDevice].systemVersion compare: @"3.1.3" options: NSNumericSearch];
if (order == NSOrderedSame || order == NSOrderedDescending) {
    // OS version >= 3.1.3
} else {
    // OS version < 3.1.3
}

所有的答案看起来都有点太大了。 我只用:

if (SYSTEM_VERSION_GREATER_THAN(@"7.0")){(..CODE...)}
if (SYSTEM_VERSION_EQUAL_TO(@"7.0")){(..CODE...)}
if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")){(..CODE...)}
if (SYSTEM_VERSION_LESS_THAN(@"7.0")){(..CODE...)}
if (SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(@"7.0")){(..CODE...)}

当然，将@“7.0”替换为所需的操作系统版本。