我正在使用Generics添加不同类型,如Int,Double,Float等.我使用下面的代码,但我得到错误"二元运算符'+'不能应用于两个'T'操作数".
func add<T>(num1: T,num2: T) -> T {
return num1 + num2
}
Run Code Online (Sandbox Code Playgroud) 我在从api请求数据时遇到此错误.我想要的只是获取消息"请求超时".在NSLocalizedDescription.怎么做到的?下面是返回错误.
错误域= NSURLErrorDomain代码= -1001"请求超时." UserInfo = 0xa5bd490 {NSErrorFailingURLStringKey = api url,NSErrorFailingURLKey = api url,NSLocalizedDescription =请求超时.,NSUnderlyingError = 0xa5763b0"请求超时."}
我创建了一个应用程序,我使用它JSQMessageViewController,它在iOS 8中工作正常.我在这个项目中使用Swift,我做桥接,因为库是用Objective-C编写的.但是在iOS 9,Xcode 7和Swift 2发布之后,我将我的代码语法转换为Swift 2并且出现问题..应用程序没有崩溃但是有一个日志错误...见下文.
2015-09-23 14:45:08.867 COC REAL WAR[1201:546997] Logging only once for UICollectionViewFlowLayout cache mismatched frame
2015-09-23 14:45:08.868 COC REAL WAR[1201:546997] UICollectionViewFlowLayout has cached frame mismatch for index path <NSIndexPath: 0xc000000000a00016> {length = 2, path = 0 - 5} - cached value: {{4, 693.221}, {312, 97}}; expected value: {{4, 596}, {312, 97}}
2015-09-23 14:45:08.868 COC REAL WAR[1201:546997] This is likely occurring because the flow layout subclass JSQMessagesCollectionViewFlowLayout is modifying attributes returned by UICollectionViewFlowLayout without copying …Run Code Online (Sandbox Code Playgroud)