我们如何以编程方式检测运行设备的iOS版本？ [重复]

本文翻译自：How can we programmatically detect which iOS version is device running on? [duplicate]

This question already has an answer here: 这个问题在这里已有答案：

• How to check iOS version? 如何查看iOS版本？ 36 answers 36个答案

I want to check if the user is running the app on iOS less than 5.0 and display a label in the app. 我想检查用户是否在低于5.0的iOS上运行应用程序并在应用程序中显示标签。

How do I detect which iOS is running on user's device programmatically? 如何以编程方式检测用户设备上运行的iOS？

Thanks! 谢谢！

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#1楼

参考：https://stackoom.com/question/wVP0/我们如何以编程方式检测运行设备的iOS版本-重复

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#2楼

A simple check for iOS version less than 5 (all versions): 对iOS版本少于5（所有版本）的简单检查：

if([[[UIDevice currentDevice] systemVersion] integerValue] < 5){
        // do something
};

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#3楼

In MonoTouch: 在MonoTouch中：

To get the Major version use: 要获得主要版本使用：

UIDevice.CurrentDevice.SystemVersion.Split('.')[0]

For minor version use: 对于次要版本使用：

UIDevice.CurrentDevice.SystemVersion.Split('.')[1]

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#4楼

Marek Sebera's is great most of the time, but if you're like me and find that you need to check the iOS version frequently, you don't want to constantly run a macro in memory because you'll experience a very slight slowdown, especially on older devices. Marek Sebera的大部分时间都很棒，但是如果你像我一样并且发现你需要经常检查iOS版本，你不希望在内存中不断运行宏，因为你会经历一个非常轻微的减速，特别是在旧设备上。

Instead, you want to compute the iOS version as a float once and store it somewhere. 相反，您希望将iOS版本计算为浮动一次并将其存储在某处。 In my case, I have a GlobalVariables singleton class that I use to check the iOS version in my code using code like this: 在我的例子中，我有一个GlobalVariables单例类，我用它来检查代码中的iOS版本，使用如下代码：

if ([GlobalVariables sharedVariables].iOSVersion >= 6.0f) {
    // do something if iOS is 6.0 or greater
}

To enable this functionality in your app, use this code (for iOS 5+ using ARC): 要在您的应用中启用此功能，请使用此代码（对于使用ARC的iOS 5+）：

GlobalVariables.h : GlobalVariables.h ：

@interface GlobalVariables : NSObject

@property (nonatomic) CGFloat iOSVersion;

    + (GlobalVariables *)sharedVariables;

@end

GlobalVariables.m : GlobalVariables.m ：

@implementation GlobalVariables

@synthesize iOSVersion;

+ (GlobalVariables *)sharedVariables {
    // set up the global variables as a static object
    static GlobalVariables *globalVariables = nil;
    // check if global variables exist
    if (globalVariables == nil) {
        // if no, create the global variables class
        globalVariables = [[GlobalVariables alloc] init];
        // get system version
        NSString *systemVersion = [[UIDevice currentDevice] systemVersion];
        // separate system version by periods
        NSArray *systemVersionComponents = [systemVersion componentsSeparatedByString:@"."];
        // set ios version
        globalVariables.iOSVersion = [[NSString stringWithFormat:@"%01d.%02d%02d", \
                                       systemVersionComponents.count < 1 ? 0 : \
                                       [[systemVersionComponents objectAtIndex:0] integerValue], \
                                       systemVersionComponents.count < 2 ? 0 : \
                                       [[systemVersionComponents objectAtIndex:1] integerValue], \
                                       systemVersionComponents.count < 3 ? 0 : \
                                       [[systemVersionComponents objectAtIndex:2] integerValue] \
                                       ] floatValue];
    }
    // return singleton instance
    return globalVariables;
}

@end

Now you're able to easily check the iOS version without running macros constantly. 现在，您可以轻松检查iOS版本，而无需经常运行宏。 Note in particular how I converted the [[UIDevice currentDevice] systemVersion] NSString to a CGFloat that is constantly accessible without using any of the improper methods many have already pointed out on this page. 请特别注意我如何将[[UIDevice currentDevice] systemVersion] NSString转换为CGFloat，这种CGFloat可以不使用许多已经在本页面指出的任何不正确的方法而不断访问。 My approach assumes the version string is in the format n.nn.nn (allowing for later bits to be missing) and works for iOS5+. 我的方法假设版本字符串的格式为n.nn.nn（允许以后的位丢失）并适用于iOS5 +。 In testing, this approach runs much faster than constantly running the macro. 在测试中，这种方法比不断运行宏的速度快得多。

Hope this helps anyone experiencing the issue I had! 希望这有助于任何人遇到我遇到的问题！

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#5楼

[[[UIDevice currentDevice] systemVersion] floatValue]

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#6楼

I know I am too late to answer this question. 我知道我来不及回答这个问题。 I am not sure does my method still working on low iOS versions (< 5.0): 我不确定我的方法是否仍适用于低iOS版本（<5.0）：

NSString *platform = [UIDevice currentDevice].model;

NSLog(@"[UIDevice currentDevice].model: %@",platform);
NSLog(@"[UIDevice currentDevice].description: %@",[UIDevice currentDevice].description);
NSLog(@"[UIDevice currentDevice].localizedModel: %@",[UIDevice currentDevice].localizedModel);
NSLog(@"[UIDevice currentDevice].name: %@",[UIDevice currentDevice].name);
NSLog(@"[UIDevice currentDevice].systemVersion: %@",[UIDevice currentDevice].systemVersion);
NSLog(@"[UIDevice currentDevice].systemName: %@",[UIDevice currentDevice].systemName);

You can get these results: 你可以得到这些结果：

[UIDevice currentDevice].model: iPhone
[UIDevice currentDevice].description: <UIDevice: 0x1cd75c70>
[UIDevice currentDevice].localizedModel: iPhone
[UIDevice currentDevice].name: Someones-iPhone002
[UIDevice currentDevice].systemVersion: 6.1.3
[UIDevice currentDevice].systemName: iPhone OS