我想检查设备的iOS版本是否大于3.1.3 我尝试了以下方法:
[[UIDevice currentDevice].systemVersion floatValue]
但是不管用，我只想要一个:
if (version > 3.1.3) { }
我怎样才能做到这一点呢?
当前回答
一个在obj - c++ 11中更通用的版本(你可能会用NSString/C函数替换其中的一些东西，但这不是那么冗长。这给了你两种机制。splitSystemVersion为你提供了一个包含所有部分的数组，如果你只是想打开主版本(例如switch([self splitSystemVersion][0]) {case 4: break;案例5:断裂;})。
#include <boost/lexical_cast.hpp>
- (std::vector<int>) splitSystemVersion {
std::string version = [[[UIDevice currentDevice] systemVersion] UTF8String];
std::vector<int> versions;
auto i = version.begin();
while (i != version.end()) {
auto nextIllegalChar = std::find_if(i, version.end(), [] (char c) -> bool { return !isdigit(c); } );
std::string versionPart(i, nextIllegalChar);
i = std::find_if(nextIllegalChar, version.end(), isdigit);
versions.push_back(boost::lexical_cast<int>(versionPart));
}
return versions;
}
/** Losslessly parse system version into a number
* @return <0>: the version as a number,
* @return <1>: how many numeric parts went into the composed number. e.g.
* X.Y.Z = 3. You need this to know how to compare again <0>
*/
- (std::tuple<int, int>) parseSystemVersion {
std::string version = [[[UIDevice currentDevice] systemVersion] UTF8String];
int versionAsNumber = 0;
int nParts = 0;
auto i = version.begin();
while (i != version.end()) {
auto nextIllegalChar = std::find_if(i, version.end(), [] (char c) -> bool { return !isdigit(c); } );
std::string versionPart(i, nextIllegalChar);
i = std::find_if(nextIllegalChar, version.end(), isdigit);
int part = (boost::lexical_cast<int>(versionPart));
versionAsNumber = versionAsNumber * 100 + part;
nParts ++;
}
return {versionAsNumber, nParts};
}
/** Assume that the system version will not go beyond X.Y.Z.W format.
* @return The version string.
*/
- (int) parseSystemVersionAlt {
std::string version = [[[UIDevice currentDevice] systemVersion] UTF8String];
int versionAsNumber = 0;
int nParts = 0;
auto i = version.begin();
while (i != version.end() && nParts < 4) {
auto nextIllegalChar = std::find_if(i, version.end(), [] (char c) -> bool { return !isdigit(c); } );
std::string versionPart(i, nextIllegalChar);
i = std::find_if(nextIllegalChar, version.end(), isdigit);
int part = (boost::lexical_cast<int>(versionPart));
versionAsNumber = versionAsNumber * 100 + part;
nParts ++;
}
// don't forget to pad as systemVersion may have less parts (i.e. X.Y).
for (; nParts < 4; nParts++) {
versionAsNumber *= 100;
}
return versionAsNumber;
}
其他回答
一个在obj - c++ 11中更通用的版本(你可能会用NSString/C函数替换其中的一些东西，但这不是那么冗长。这给了你两种机制。splitSystemVersion为你提供了一个包含所有部分的数组，如果你只是想打开主版本(例如switch([self splitSystemVersion][0]) {case 4: break;案例5:断裂;})。
#include <boost/lexical_cast.hpp>
- (std::vector<int>) splitSystemVersion {
std::string version = [[[UIDevice currentDevice] systemVersion] UTF8String];
std::vector<int> versions;
auto i = version.begin();
while (i != version.end()) {
auto nextIllegalChar = std::find_if(i, version.end(), [] (char c) -> bool { return !isdigit(c); } );
std::string versionPart(i, nextIllegalChar);
i = std::find_if(nextIllegalChar, version.end(), isdigit);
versions.push_back(boost::lexical_cast<int>(versionPart));
}
return versions;
}
/** Losslessly parse system version into a number
* @return <0>: the version as a number,
* @return <1>: how many numeric parts went into the composed number. e.g.
* X.Y.Z = 3. You need this to know how to compare again <0>
*/
- (std::tuple<int, int>) parseSystemVersion {
std::string version = [[[UIDevice currentDevice] systemVersion] UTF8String];
int versionAsNumber = 0;
int nParts = 0;
auto i = version.begin();
while (i != version.end()) {
auto nextIllegalChar = std::find_if(i, version.end(), [] (char c) -> bool { return !isdigit(c); } );
std::string versionPart(i, nextIllegalChar);
i = std::find_if(nextIllegalChar, version.end(), isdigit);
int part = (boost::lexical_cast<int>(versionPart));
versionAsNumber = versionAsNumber * 100 + part;
nParts ++;
}
return {versionAsNumber, nParts};
}
/** Assume that the system version will not go beyond X.Y.Z.W format.
* @return The version string.
*/
- (int) parseSystemVersionAlt {
std::string version = [[[UIDevice currentDevice] systemVersion] UTF8String];
int versionAsNumber = 0;
int nParts = 0;
auto i = version.begin();
while (i != version.end() && nParts < 4) {
auto nextIllegalChar = std::find_if(i, version.end(), [] (char c) -> bool { return !isdigit(c); } );
std::string versionPart(i, nextIllegalChar);
i = std::find_if(nextIllegalChar, version.end(), isdigit);
int part = (boost::lexical_cast<int>(versionPart));
versionAsNumber = versionAsNumber * 100 + part;
nParts ++;
}
// don't forget to pad as systemVersion may have less parts (i.e. X.Y).
for (; nParts < 4; nParts++) {
versionAsNumber *= 100;
}
return versionAsNumber;
}
UIDevice + IOSVersion.h
@interface UIDevice (IOSVersion)
+ (BOOL)isCurrentIOSVersionEqualToVersion:(NSString *)iOSVersion;
+ (BOOL)isCurrentIOSVersionGreaterThanVersion:(NSString *)iOSVersion;
+ (BOOL)isCurrentIOSVersionGreaterThanOrEqualToVersion:(NSString *)iOSVersion;
+ (BOOL)isCurrentIOSVersionLessThanVersion:(NSString *)iOSVersion;
+ (BOOL)isCurrentIOSVersionLessThanOrEqualToVersion:(NSString *)iOSVersion
@end
UIDevice + IOSVersion.m
#import "UIDevice+IOSVersion.h"
@implementation UIDevice (IOSVersion)
+ (BOOL)isCurrentIOSVersionEqualToVersion:(NSString *)iOSVersion
{
return [[[UIDevice currentDevice] systemVersion] compare:iOSVersion options:NSNumericSearch] == NSOrderedSame;
}
+ (BOOL)isCurrentIOSVersionGreaterThanVersion:(NSString *)iOSVersion
{
return [[[UIDevice currentDevice] systemVersion] compare:iOSVersion options:NSNumericSearch] == NSOrderedDescending;
}
+ (BOOL)isCurrentIOSVersionGreaterThanOrEqualToVersion:(NSString *)iOSVersion
{
return [[[UIDevice currentDevice] systemVersion] compare:iOSVersion options:NSNumericSearch] != NSOrderedAscending;
}
+ (BOOL)isCurrentIOSVersionLessThanVersion:(NSString *)iOSVersion
{
return [[[UIDevice currentDevice] systemVersion] compare:iOSVersion options:NSNumericSearch] == NSOrderedAscending;
}
+ (BOOL)isCurrentIOSVersionLessThanOrEqualToVersion:(NSString *)iOSVersion
{
return [[[UIDevice currentDevice] systemVersion] compare:iOSVersion options:NSNumericSearch] != NSOrderedDescending;
}
@end
试试下面的代码:
NSString *versionString = [[UIDevice currentDevice] systemVersion];
使用nv-ios-version项目(Apache License, Version 2.0)中包含的Version类，很容易获取和比较iOS版本。下面的示例代码转储iOS版本，并检查版本是否大于或等于6.0。
// Get the system version of iOS at runtime.
NSString *versionString = [[UIDevice currentDevice] systemVersion];
// Convert the version string to a Version instance.
Version *version = [Version versionWithString:versionString];
// Dump the major, minor and micro version numbers.
NSLog(@"version = [%d, %d, %d]",
version.major, version.minor, version.micro);
// Check whether the version is greater than or equal to 6.0.
if ([version isGreaterThanOrEqualToMajor:6 minor:0])
{
// The iOS version is greater than or equal to 6.0.
}
// Another way to check whether iOS version is
// greater than or equal to 6.0.
if (6 <= version.major)
{
// The iOS version is greater than or equal to 6.0.
}
项目页面:nv-ios-version TakahikoKawasaki / nv-ios-version
博客:获取并比较iOS版本在运行时与版本类 获取并比较iOS版本在运行时与版本类
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);
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