Swift 中由字符串转化成类名

OC中由字符串转化成类名，很直接， NSClassFromString("类名")即可

但是Swift 中就不能直接转化了：如果想使用即可用下面两种方法(Xcode6.1，现在6.3/ 6.4)

 let classStringName = "_TtC\(appName!.utf16Count)\(appName!)\(count(className))\(className)"//xcode 6.1-6.2 beta

 class func swiftClassFromString(className: String) -> AnyClass! {
        //method1
        //方法 NSClassFromString 在Swift中已经不起作用了no effect，需要适当更改
        if  var appName: String? = NSBundle.mainBundle().objectForInfoDictionaryKey("CFBundleName") as! String? {
            // generate the full name of your class (take a look into your "appname-swift.h" file)
            //            let classStringName = "_TtC\(appName!.utf16Count)\(appName!)\(count(className))\(className)"//xcode 6.1-6.2 beta
            let classStringName = "_TtC\(count(appName!))\(appName!)\(count(className))\(className)"
            var  cls: AnyClass? = NSClassFromString(classStringName)
            //  method2
            //cls = NSClassFromString("\(appName!).\(className)")
            assert(cls != nil, "class not found,please check className")
            return cls
            
        }
        return nil;
    }