之前项目可以编译和运行，好好的。
去掉了一个不用的库之后，结果再去编译就出错了：
A declaration cannot be both ‘final’ and ‘dynamic’
CompileSwift normal i386 /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/CrifanLib.swift
cd /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift -frontend -c /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/ReportViewController.swift -primary-file /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/CrifanLib.swift /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/TimelineViewController.swift /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/GlobalValues.swift /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/TimelineTableViewCell.swift /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/MainTabViewController.swift /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/Memo.swift /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/GlobalConstants.swift /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/CrifanLibDemo.swift /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/AppDelegate.swift -target i386-apple-ios9.3 -enable-objc-interop -sdk /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator9.3.sdk -I /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Products/Debug-iphonesimulator -F /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Products/Debug-iphonesimulator -F /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/Carthage/Build/iOS -enable-testing -g -import-objc-header /Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales/QorosSales/QorosSales-Bridging-Header.h -module-cache-path /Users/crifan/Library/Developer/Xcode/DerivedData/ModuleCache -D COCOAPODS -serialize-debugging-options -Xcc -I/Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/swift-overrides.hmap -Xcc -iquote -Xcc /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/QorosSales-generated-files.hmap -Xcc -I/Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/QorosSales-own-target-headers.hmap -Xcc -I/Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/QorosSales-all-non-framework-target-headers.hmap -Xcc -ivfsoverlay -Xcc /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/all-product-headers.yaml -Xcc -iquote -Xcc /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/QorosSales-project-headers.hmap -Xcc -I/Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Products/Debug-iphonesimulator/include -Xcc -I/Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/DerivedSources/i386 -Xcc -I/Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/DerivedSources -Xcc -DDEBUG=1 -Xcc -DCOCOAPODS=1 -Xcc -working-directory/Users/crifan/dev/dev_root/daryun/Projects/Qoros/QorosSales/Sourcecode/QorosSales -emit-module-doc-path /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/Objects-normal/i386/CrifanLib~partial.swiftdoc -Onone -module-name QorosSales -emit-module-path /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/Objects-normal/i386/CrifanLib~partial.swiftmodule -serialize-diagnostics-path /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/Objects-normal/i386/CrifanLib.dia -emit-dependencies-path /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/Objects-normal/i386/CrifanLib.d -emit-reference-dependencies-path /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/Objects-normal/i386/CrifanLib.swiftdeps -o /Users/crifan/Library/Developer/Xcode/DerivedData/QorosSales-fdvmkfwiibblhkeaqjznadykdyuj/Build/Intermediates/QorosSales.build/Debug-iphonesimulator/QorosSales.build/Objects-normal/i386/CrifanLib.o
<unknown>:0: error: a declaration cannot be both ‘final’ and ‘dynamic’
搜：
A declaration cannot be both ‘final’ and ‘dynamic’
A declaration cannot be both ‘final’ and ‘dynamic’ error in Swift 1.2 – Stack Overflow
现在问题最诡异的是：
为何之前编译没有问题？？？
并且，对于：
/CrifanLibDemo.swift
代码里面，并没有static之类的
为何也报错？
a declaration cannot be both ‘final’ and ‘dynamic’ – SiamPig的专栏 – 博客频道 – CSDN.NET
swift/attr_dynamic.swift at master · apple/swift
去看了看final和dynamic：
也都没有我自己写的代码，都是第三方的库
难道因为是昨天添加了一个：
extension NSDate
{
static let emptyDate:NSDate = NSDate(timeIntervalSince1970: 0)
}
换种写法试试：
但是此处不是我自己写的NSDate（是系统自己的）
所以没法写成：
class MyClass {
static var someProperty = 1
}
extension MyClass {
//something else
}
只能想办法：
Extensions may not contain stored properties
再去试试其他：
‘let’ declarations cannot be computed properties
最后：
//static let emptyDate:NSDate = NSDate(timeIntervalSince1970: 0)
var emptyDate:NSDate {
return NSDate(timeIntervalSince1970: 0)
}
至少此处是可以通过编译了
再去clean项目，重新编译，看看能否解决上述的问题
然后之前的调用方式：
if !memoItem.time.isEqualToDate(NSDate.emptyDate) {
也要改为：
if !memoItem.time.isEqualToDate(NSDate().emptyDate) {
最后果然可以正常编译运行项目了。
再去参考：
A declaration cannot be both ‘final’ and ‘dynamic’ error in Swift 1.2 – Stack Overflow
加上：@nonobjc，估计更好：
//static let emptyDate:NSDate = NSDate(timeIntervalSince1970: 0)
// var emptyDate:NSDate {
// return NSDate(timeIntervalSince1970: 0)
// }
@nonobjc static let emptyDate:NSDate = NSDate(timeIntervalSince1970: 0)
调用的地方，也又是从：
NSDate().emptyDate
改为之前的：
NSDate.emptyDate
也是可以的。
［总结］
此处的：
extension NSDate
{
static let emptyDate:NSDate = NSDate(timeIntervalSince1970: 0)
}
报错：
办法1:
如果是自己写的类，可以写成：
class NSDate {
static let emptyDate:NSDate = NSDate(timeIntervalSince1970: 0)
}
extension NSDate {
//something else
}
但是很明显，这个NSDate是系统的类，没法这么写。
办法2：
改为：
extension NSDate {
var emptyDate:NSDate {
return NSDate(timeIntervalSince1970: 0)
}
}
－》
当然，对应的调用方式就从：
NSDate.emptyDate
变成了：
NSDate().emptyDate
办法3：
改为：
extension NSDate
{
@nonobjc static let emptyDate:NSDate = NSDate(timeIntervalSince1970: 0)
}
前提：
是swift 2.0
其他调用此（函数）属性的地方，没有object-c代码
总的来说：
如果条件符合上面，比如我这里就是使用最新的swift 2.2，且调用此段代码的全是swift没有object-c，那么用方法3，比较合适。
转载请注明：在路上 » ［已解决］iOS项目编译出错：A declaration cannot be both final and dynamic