比较Objective-C中的版本号

Question

我正在编写一个接收带有项目和版本号的数据的应用程序.数字格式为"1.0.1"或"1.2.5".如何比较这些版本号？我认为他们必须先格式化为字符串,不是吗？我有什么选择来确定"1.2.5"在"1.0.1"之后？

Answer 1

这是比较版本的最简单方法,请记住"1"<"1.0"<"1.0.0":

NSString* requiredVersion = @"1.2.0";
NSString* actualVersion = @"1.1.5";

if ([requiredVersion compare:actualVersion options:NSNumericSearch] == NSOrderedDescending) {
  // actualVersion is lower than the requiredVersion
}

Answer 2

我将添加我的方法,它将严格的数字版本(没有a,b,RC等)与任意数量的组件进行比较.

+ (NSComparisonResult)compareVersion:(NSString*)versionOne toVersion:(NSString*)versionTwo {
    NSArray* versionOneComp = [versionOne componentsSeparatedByString:@"."];
    NSArray* versionTwoComp = [versionTwo componentsSeparatedByString:@"."];

    NSInteger pos = 0;

    while ([versionOneComp count] > pos || [versionTwoComp count] > pos) {
        NSInteger v1 = [versionOneComp count] > pos ? [[versionOneComp objectAtIndex:pos] integerValue] : 0;
        NSInteger v2 = [versionTwoComp count] > pos ? [[versionTwoComp objectAtIndex:pos] integerValue] : 0;
        if (v1 < v2) {
            return NSOrderedAscending;
        }
        else if (v1 > v2) {
            return NSOrderedDescending;
        }
        pos++;
    }

    return NSOrderedSame;
}

Answer 3

这是对Nathan de Vries的解释,以解决1 <1.0 <1.0.0等问题.

首先,我们可以在我们的版本字符串上解决额外".0"的问题,其中包含以下NSString类别:

@implementation NSString (VersionNumbers)
- (NSString *)shortenedVersionNumberString {
    static NSString *const unnecessaryVersionSuffix = @".0";
    NSString *shortenedVersionNumber = self;

    while ([shortenedVersionNumber hasSuffix:unnecessaryVersionSuffix]) {
        shortenedVersionNumber = [shortenedVersionNumber substringToIndex:shortenedVersionNumber.length - unnecessaryVersionSuffix.length];
    }

    return shortenedVersionNumber;
}
@end

通过上述NSString类别,我们可以缩短版本号以减少不必要的.0

NSString* requiredVersion = @"1.2.0";
NSString* actualVersion = @"1.1.5";

requiredVersion = [requiredVersion shortenedVersionNumberString]; // now 1.2
actualVersion = [actualVersion shortenedVersionNumberString]; // still 1.1.5

现在我们仍然可以使用Nathan de Vries提出的非常简单的方法:

if ([requiredVersion compare:actualVersion options:NSNumericSearch] == NSOrderedDescending) {
  // actualVersion is lower than the requiredVersion
}

Answer 4

Sparkle(最受欢迎的MacOS软件更新框架)具有SUStandardVersionComparator类,可以实现此目的,还可以考虑构建数和beta标记.即正确比较1.0.5 > 1.0.5b7或2.0 (2345) > 2.0 (2100).代码只使用Foundation,因此在iOS上也可以正常工作.

Answer 5

我自己制作,使用分类..

资源..

@implementation NSString (VersionComparison)
- (NSComparisonResult)compareVersion:(NSString *)version{
    NSArray *version1 = [self componentsSeparatedByString:@"."];
    NSArray *version2 = [version componentsSeparatedByString:@"."];
    for(int i = 0 ; i < version1.count || i < version2.count; i++){
        NSInteger value1 = 0;
        NSInteger value2 = 0;
        if(i < version1.count){
            value1 = [version1[i] integerValue];
        }
        if(i < version2.count){
            value2 = [version2[i] integerValue];
        }
        if(value1  == value2){
            continue;
        }else{
            if(value1 > value2){
                return NSOrderedDescending;
            }else{
                return NSOrderedAscending;
            }
        }
    }
    return NSOrderedSame;
}

测试..

NSString *version1 = @"3.3.1";
NSString *version2 = @"3.12.1";
NSComparisonResult result = [version1 compareVersion:version2];
switch (result) {
    case NSOrderedAscending:
    case NSOrderedDescending:
    case NSOrderedSame:
         break;
    }

Answer 6

查看我的NSString类别,该类别在github上实现简单的版本检查; https://github.com/stijnster/NSString-compareToVersion

[@"1.2.2.4" compareToVersion:@"1.2.2.5"];

这将返回一个NSComparisonResult,它比使用更准确;

[@"1.2.2" compare:@"1.2.2.5" options:NSNumericSearch]

还增加了助手;

[@"1.2.2.4" isOlderThanVersion:@"1.2.2.5"];
[@"1.2.2.4" isNewerThanVersion:@"1.2.2.5"];
[@"1.2.2.4" isEqualToVersion:@"1.2.2.5"];
[@"1.2.2.4" isEqualOrOlderThanVersion:@"1.2.2.5"];
[@"1.2.2.4" isEqualOrNewerThanVersion:@"1.2.2.5"];