我正在用Swift检查系统信息。我发现，这可以通过代码来实现:
var sysData:CMutablePointer<utsname> = nil
let retVal:CInt = uname(sysData)
这段代码有两个问题:
sysData的初始值应该是什么?这个例子在retVal中给出-1可能是因为sysData为nil。 如何从sysData读取信息?
当前回答
根据Matt Thompson的回答，这里有一个带有各自单元测试的方法，可以在iOS 7及以上版本(包括iOS 9，不再让你检查NSFoundationNumber)上与Swift和Objective-c一起工作:
+ (BOOL) isAtLeastOSVersion:(NSString *)osVersion
{
switch ([[UIDevice currentDevice].systemVersion compare:osVersion options:NSNumericSearch]) {
case NSOrderedSame:
case NSOrderedDescending:
return YES;
default:
return NO;
}
}
.
@interface ANFakeCurrDevice : NSObject
@property (nonatomic, strong) NSString *systemVersion;
@end
@implementation ANFakeCurrDevice
@end
@implementation MyHelperClassUnitTests
- (void)setUp {
[super setUp];
}
- (void)tearDown {
[super tearDown];
}
- (void)test_isAtLeastOSVersion
{
id deviceMock = [OCMockObject niceMockForClass:[UIDevice class]];
ANFakeCurrDevice *fakeCurrDevice = [ANFakeCurrDevice new];
fakeCurrDevice.systemVersion = @"99.9.9";
[[[deviceMock stub] andReturn:fakeCurrDevice] currentDevice];
XCTAssertTrue([[UIDevice currentDevice].systemVersion isEqualToString:@"99.9.9"]);
fakeCurrDevice.systemVersion = @"1.0.1";
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"1"]);
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"1.0"]);
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"1.0.1"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"1.0.2"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"1.1.0"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"2"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"2.0"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"2.0.0"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"2.0.1"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"2.1.0"]);
fakeCurrDevice.systemVersion = @"8.4.0";
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"7.0.1"]);
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"8"]);
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"8.4"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"8.4.1"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"8.4.2"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"9.0"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"9.0.1"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"9.0.2"]);
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"8.4"] && ![ANConstants isAtLeastOSVersion:@"9.0"]);
fakeCurrDevice.systemVersion = @"8.4.1";
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"8.4"] && ![ANConstants isAtLeastOSVersion:@"9.0"]);
}
@end
其他回答
如果你正在使用Swift 2，并且你想要检查操作系统版本以使用某个API，你可以使用新的可用性特性:
if #available(iOS 8, *) {
//iOS 8+ code here.
}
else {
//Code for iOS 7 and older versions.
//An important note: if you use #availability, Xcode will also
//check that you don't use anything that was introduced in iOS 8+
//inside this `else` block. So, if you try to use UIAlertController
//here, for instance, it won't compile. And it's great.
}
我写这个答案是因为它是谷歌中swift 2 check系统版本查询的第一个问题。
对于iOS，请尝试:
var systemVersion = UIDevice.current.systemVersion
对于OS X，尝试:
var systemVersion = NSProcessInfo.processInfo().operatingSystemVersion
如果你只是想检查用户是否至少运行了一个特定的版本，你也可以使用以下Swift 2功能，它适用于iOS和OS X:
if #available(iOS 9.0, *) {
// use the feature only available in iOS 9
// for ex. UIStackView
} else {
// or use some work around
}
但不建议检查操作系统版本。最好检查您想要使用的功能在设备上是否可用，而不是比较版本号。 对于iOS，如前所述，你应该检查它是否响应选择器; 如:
if (self.respondsToSelector(Selector("showViewController"))) {
self.showViewController(vc, sender: self)
} else {
// some work around
}
根据Matt Thompson的回答，这里有一个带有各自单元测试的方法，可以在iOS 7及以上版本(包括iOS 9，不再让你检查NSFoundationNumber)上与Swift和Objective-c一起工作:
+ (BOOL) isAtLeastOSVersion:(NSString *)osVersion
{
switch ([[UIDevice currentDevice].systemVersion compare:osVersion options:NSNumericSearch]) {
case NSOrderedSame:
case NSOrderedDescending:
return YES;
default:
return NO;
}
}
.
@interface ANFakeCurrDevice : NSObject
@property (nonatomic, strong) NSString *systemVersion;
@end
@implementation ANFakeCurrDevice
@end
@implementation MyHelperClassUnitTests
- (void)setUp {
[super setUp];
}
- (void)tearDown {
[super tearDown];
}
- (void)test_isAtLeastOSVersion
{
id deviceMock = [OCMockObject niceMockForClass:[UIDevice class]];
ANFakeCurrDevice *fakeCurrDevice = [ANFakeCurrDevice new];
fakeCurrDevice.systemVersion = @"99.9.9";
[[[deviceMock stub] andReturn:fakeCurrDevice] currentDevice];
XCTAssertTrue([[UIDevice currentDevice].systemVersion isEqualToString:@"99.9.9"]);
fakeCurrDevice.systemVersion = @"1.0.1";
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"1"]);
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"1.0"]);
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"1.0.1"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"1.0.2"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"1.1.0"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"2"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"2.0"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"2.0.0"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"2.0.1"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"2.1.0"]);
fakeCurrDevice.systemVersion = @"8.4.0";
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"7.0.1"]);
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"8"]);
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"8.4"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"8.4.1"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"8.4.2"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"9.0"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"9.0.1"]);
XCTAssertFalse([ANConstants isAtLeastOSVersion:@"9.0.2"]);
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"8.4"] && ![ANConstants isAtLeastOSVersion:@"9.0"]);
fakeCurrDevice.systemVersion = @"8.4.1";
XCTAssertTrue([ANConstants isAtLeastOSVersion:@"8.4"] && ![ANConstants isAtLeastOSVersion:@"9.0"]);
}
@end
我做了帮助函数，从下面的链接转移到swift:
我们如何通过程序检测设备运行的iOS版本?
func SYSTEM_VERSION_EQUAL_TO(version: String) -> Bool {
return UIDevice.currentDevice().systemVersion.compare(version,
options: NSStringCompareOptions.NumericSearch) == NSComparisonResult.OrderedSame
}
func SYSTEM_VERSION_GREATER_THAN(version: String) -> Bool {
return UIDevice.currentDevice().systemVersion.compare(version,
options: NSStringCompareOptions.NumericSearch) == NSComparisonResult.OrderedDescending
}
func SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(version: String) -> Bool {
return UIDevice.currentDevice().systemVersion.compare(version,
options: NSStringCompareOptions.NumericSearch) != NSComparisonResult.OrderedAscending
}
func SYSTEM_VERSION_LESS_THAN(version: String) -> Bool {
return UIDevice.currentDevice().systemVersion.compare(version,
options: NSStringCompareOptions.NumericSearch) == NSComparisonResult.OrderedAscending
}
func SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(version: String) -> Bool {
return UIDevice.currentDevice().systemVersion.compare(version,
options: NSStringCompareOptions.NumericSearch) != NSComparisonResult.OrderedDescending
}
它可以这样使用:
SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO("7.0")
斯威夫特4.2
func SYSTEM_VERSION_EQUAL_TO(version: String) -> Bool {
return UIDevice.current.systemVersion.compare(version, options: .numeric) == .orderedSame
}
func SYSTEM_VERSION_GREATER_THAN(version: String) -> Bool {
return UIDevice.current.systemVersion.compare(version, options: .numeric) == .orderedDescending
}
func SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(version: String) -> Bool {
return UIDevice.current.systemVersion.compare(version, options: .numeric) != .orderedAscending
}
func SYSTEM_VERSION_LESS_THAN(version: String) -> Bool {
return UIDevice.current.systemVersion.compare(version, options: .numeric) == .orderedAscending
}
func SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(version: String) -> Bool {
return UIDevice.current.systemVersion.compare(version, options: .numeric) != .orderedDescending
}
在Swift 2及更高版本中，检查系统版本(以及许多其他版本)最简单和最简单的方法是:
if #available(iOS 9.0, *) { // check for iOS 9.0 and later
}
此外，使用#available你可以检查这些版本:
iOS
iOSApplicationExtension
macOS
macOSApplicationExtension
watchOS
watchOSApplicationExtension
tvOS
tvOSApplicationExtension
swift
推荐文章
- 我如何获得iOS 7默认的蓝色编程?
- UITapGestureRecognizer破坏UITableView didSelectRowAtIndexPath
- 在Objective-C中@property保留，赋值，复制，非原子
- 6.5英寸屏幕的App store截图大小是多少?
- 我如何使一个enum可解码在Swift?
- 我如何在NSAttributedString中创建一个可点击的链接?
- iOS测试/规格TDD/BDD以及集成和验收测试
- 停止UIWebView垂直“弹跳”?
- 启动屏幕故事板不显示图像
- HTTP请求在Swift与POST方法
- 在Mac上安装R -警告消息:设置LC_CTYPE失败，使用“C”
- 是否可以为iPhone应用程序(如YouTube和地图)注册一个基于http+域的URL方案?
- 模拟器错误fbssystemservicdomain代码4
- 为什么cURL返回错误“(23)Failed writing body”?
- 节点和错误:EMFILE，打开的文件太多
